Designing a Cost-Effective and high Efficient

In the Name of God

A Proposal for:

Designing a Cost-Effective and high Efficient Business Jet Light Business Jet Family Design Challenge 2017

AIAA Graduate & Undergraduate Team Aircraft Student Design Competition

Copyright © 2017 by DeBiz. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.

SIGNATURE PAGE

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Designing a Cost-Effective and high Efficient Business Jet

Acknowledgement DeBiz would like to thank our friends and families for their emotional supports and patience as we have been completing this proposal. We also extend our special gratitude to Engineer Ehsan ImaniNejad, who helped us in structural design.Same goes for Mr AmirHossein PourShaaban, who had guided us with great ideas for cost estimations. We would like to send our deepest regards to Mr Amin PourMohamdian because of his remarkable help for overall structural design. We also had Miss Rana Nouri with us with her great positive energy. Finally, we are deeply indebted to Miss Mahsa AbbasZadeh Nakhost, who spent countless hours in editing the final manuscript.

Executive Summary “…If you don’t make a decision, a decision will be made for you.”-Prof. S.M.B Malaek DeBiz is a team of nine undergraduate students, all from Aerospace Engineering Department of Sharif University of Technology ; for each team-member exhibits tremendous desire to become a system-engineer. Toward achieving their goal, participation in an AIAA challenging aircraft design competition is a must. We as DeBiz members believe a wining proposal requires chaotic-good decision makers with reliable BOID1 architecture. By “Chaotic”, we mean that we are able to recognize current competition and we are able to propose creative and innovative ideas to influence the market in our favor and not just modify current designs. By “Good”, we mean that we intend to keep growing in the long-run and for the years to come and short-term profits would not form the basis for our decisions. This is how our team has been formed and impelled to finish the AIAA 2017 challenge. We enjoyed the differences among team members and we firmly believe such differences has led to a family of UniBee; which is going to be the fastest light business jet with the longest range in the 2022 and beyond. Currently, UniBee has two family members; that belong to light class of Business Jet (Bizjet). The first comes with standard 6 seats and the second with 8 seats; for which current global market trends suggest a bright future. High level of commonality between the two versions lead to considerable acquisition-cost reduction; while providing the opportunity for the potential customers to explore their options (Table 1). The approach coincides with RFP calling for two distinctive versions; while considers the fact that certifying under FAR-23 requirements is much less than that for FAR-25 and at the same time each version must consider future enhancements. Based on extensive historical reviews, expert interview and brainstorming, we at DeBiz have come to the following conclusions:

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Beliefs– Obligations-Intensions-Desires 1|Page

Designing a Cost-Effective and high Efficient Business Jet 1- UniBee family offers relatively better performance characteristics w.r.t the competition; while keeping the direct operating costs (DOC) to an attractive level compared to that by the competition. 2- From Handling Quality point of view, both UniBee versions are fairly identical, so a pilot trained on UniBee 620 could fly UniBee 822 without any extra training. We note that inertia parameters of the two versions are not the same; nevertheless, an adaptive SAS (Stability Augmentation System) can compensate for the difference between the two versions. Table 1, UniBee Family General Specification

Specification Airplane Crew Crew Weight max payload maximum speed Stall Speed Typical Range cruise altitude empty weight T/W W/S L/D

Quantity General UniBee822 1 200 2800 490 93 2550 43000 13275 0.38 70 17 Wing

Aspect Ratio Wing Span Wing Area Taper Ratio Mean Aerodynamic Chord

Unit UniBee620 1 200 1600 490 93 3550 43000 13275 0.38 70 17

person lb. lb. knots knots nm. ft. lb. NA NA NA

7.5 47.8 305 0.4 5.2

NA ft. ft2. NA ft.

34 1.22 9.5 74

deg. NA ft. ft2.

20 7.7 19 46.7

deg. NA ft. ft2.

Vertical Tail Tail sweep Aspect Ratio Tail Span Tail Area Canard Sweep Aspect Ratio Span Area

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Contents Acknowledgement ............................................................................................................................ 1 1

RFP Overview.................................................................................................................. 9

2

DeBiz Design Space ....................................................................................................... 11

2.1

DeBiz Design Approach ....................................................................................................................... 11

2.2

DeBiz Design Objectives ...................................................................................................................... 13

3

Environmental Study .................................................................................................... 14

3.1

History .................................................................................................................................................. 14

3.2

BizJets Accident Study ........................................................................................................................ 15

3.3

Customer analysis ................................................................................................................................ 16

4

Mission Specifications ................................................................................................... 18 4.1

DeBiz Range criteria ............................................................................................................................ 19

4.2

DeBiz Mission Variations .................................................................................................................... 20

4.3

Results ................................................................................................................................................... 21

4.4

Two Different Scenarios ...................................................................................................................... 21

5

UniBee Initial Sizing ..................................................................................................... 22 5.1

UniBee Weight Sizing .......................................................................................................................... 22

5.2

UniBee Performance Sizing ................................................................................................................. 23

6

UniBee Propulsion System & Integration ................................................................... 24 6.1

UniBee Engine Type............................................................................................................................. 24

6.2

Number of engines ............................................................................................................................... 25

6.3

Location ................................................................................................................................................ 25

6.4

Thrust Calculations ............................................................................................................................. 25

6.5

Future Versions .................................................................................................................................... 26

6.6

Engine Selection ................................................................................................................................... 26

6.7

Selected engine benefits ....................................................................................................................... 29

7

UniBee Configuration ................................................................................................... 30 7.1

UniBee General Configuration Selection ........................................................................................... 30

7.2

UniBee in critical weather conditions ................................................................................................. 30

7.3

UniBee Fuel Tank ................................................................................................................................ 31

7.4

UniBee Airfoil Selection....................................................................................................................... 31

7.5

UniBee Wing Design ............................................................................................................................ 31

7.6

UniBee Wing Configuration ................................................................................................................ 32

7.7

UniBee Fuselage Design ....................................................................................................................... 33

7.8

UniBee Subsystems .............................................................................................................................. 42

8

UniBee Painting and Finishing..................................................................................... 43

9

Weight Engineering ...................................................................................................... 43 9.1

Weights Breakdown ............................................................................................................................. 44

9.2

Static Margin ........................................................................................................................................ 44

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Designing a Cost-Effective and high Efficient Business Jet 9.3

Water Tanks ......................................................................................................................................... 45

9.4

UniBee 3View ....................................................................................................................................... 46

10

UniBee Drag Polar ........................................................................................................ 47

11

UniBee Stability and Control ....................................................................................... 49 11.1

UniBee Tail sizing ................................................................................................................................ 49

11.2

UniBee Derivatives ............................................................................................................................... 51

11.3

UniBee 620 Ride Quality System during Cruise ................................................................................ 53

11.4

UniBee Family Ride Quality System during Landing ....................................................................... 62

11.5

Discussion ............................................................................................................................................. 66

12

UniBee Structural Design ............................................................................................. 66 12.1

Introduction .......................................................................................................................................... 66

12.2

Material selection ................................................................................................................................. 68

12.3

UniBee loading and v-n diagram ........................................................................................................ 69

12.4

Primary sizing estimation according to critical maneuvers .............................................................. 70

12.5

UniBee Structural Layout ................................................................................................................... 72

12.6

UniBee Flight Envelope ....................................................................................................................... 76

13

UniBee Landing Gear Selection ................................................................................... 76 13.1

Design Approach .................................................................................................................................. 76

13.2

Types ..................................................................................................................................................... 77

13.3

Landing gear selection ......................................................................................................................... 79

13.4

Landing gear model and its location .................................................................................................. 79

13.5

Design parameters ............................................................................................................................... 79

14

DeBiz Market Analysis ................................................................................................. 80 14.1

DeBiz Market Strategy ........................................................................................................................ 80

14.2

DeBiz Sale Estimation .......................................................................................................................... 81

14.3

DeBiz Market marking (Making New demand) ................................................................................ 83

15

DeBiz Life Cycle Cost Analysis .................................................................................... 86 15.1

DeBiz Cost estimation .......................................................................................................................... 86

15.2

Non-recurring development costs ....................................................................................................... 86

15.3

DeBiz RDTE cost comparison for Hornet and UniBee ..................................................................... 87

15.4

DeBiz Flyaway costs ............................................................................................................................. 89

16

DeBiz Conclusion .......................................................................................................... 95

17

References ...................................................................................................................... 96

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LIST OF FIGURES Figure 1, V model of system design ................................................................................................ 11 Figure 2, Task Based DSM Strategy Baseline ................................................................................. 12 Figure 3, Lower Triangle Task Based DSM .................................................................................... 12 Figure 4, Physical DSM ................................................................................................................... 13 Figure 5- Parameter-based DSM .................................................................................................... 14 Figure 6, Classification of Failure ................................................................................................... 15 Figure 7, Accident Phase ................................................................................................................. 15 Figure 8, tomorrow’s Luxury Traveler’s Distributions ................................................................... 16 Figure 9. How the UniBee may use FT/AT, CC and CDA ............................................................. 18 Figure 10. World range map ............................................................................................................ 20 Figure 11. Payload-Range diagram ................................................................................................. 23 Figure 12. Performance Matching Diagram .................................................................................... 23 Figure 13 Thrust vs Speed ............................................................................................................... 28 Figure 14, DeBiz nose layout .......................................................................................................... 34 Figure 15, Cabin Cross Section ....................................................................................................... 36 Figure 16. Based on “The Real World of Business Aviation” [12] ................................................. 38 Figure 17, UniBee 822 Interior Design ........................................................................................... 39 Figure 18, UniBee 620 Business Type Interior Design ................................................................... 39 Figure 19, UniBee 620 Personal/Business interior design............................................................... 40 Figure 20, UniBee 620 Personal Interior Design ............................................................................. 40 Figure 21Brief List of Subsystems .................................................................................................. 43 Figure 22, Subsystems allocation .................................................................................................... 43 Figure 23, Weight-C.G. Excursion Diagram ................................................................................... 44 Figure 24, UniBee 3View ................................................................................................................ 47 Figure 25, Drag Polar Diagram at M = 0.85 .................................................................................... 49 Figure 26, Canard X- Plot ................................................................................................................ 49 Figure 27, Vertical tail area ............................................................................................................. 50 Figure 28, Unibee620 Cruise in presence of gust ............................................................................ 54 Figure 29, Gust alleviation sys. Block diagram ............................................................................... 56 Figure 30, Active Control ride quality sys. ...................................................................................... 57 Figure 31, 〖a_y〗_Acc/β_g, β/β_g ,r/β_g ,φ/β_g responses 〖〖,a〗_y〗_Acc Total, R.M.S. and Error results for Dryden gust model ............................................................................................... 58 Figure 32, Total ay and r.m.s for three controllers, step gust input ................................................ 59

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Designing a Cost-Effective and high Efficient Business Jet Figure 33, 〖a_y〗_Acc/β_g ,β/β_g , r/β_g , φ/β_g responses, 〖a_y〗_Acc Total, R.M.S. and error results ........................................................................................................................................... 60 Figure 34, β_g step input, 〖a_y〗_Acc Total and R.M.S. results ................................................ 61 Figure 35, Unibees landing in presence of gust ............................................................................... 62 Figure 36, Pitch attitude hold system to alleviate aircraft response to horizontal gust velocity ...... 64 Figure 37, θ response and gust alleviation system 1 results, step input horizontal gust velocity .... 65 Figure 38, 𝜃 response and gust alleviation system 2 results, Dryden input horizontal gust velocity .............................................................................................................................................................. 66 Figure 39, Trends and Forecast for Material ................................................................................... 67 Figure 40, Manufacturing and Process Cost .................................................................................... 67 Figure 41, Internal Parts Material .................................................................................................... 69 Figure 42, External Shell Material................................................................................................... 69 Figure 43, UniBee V-n Diagram...................................................................................................... 70 Figure 44, Special Maneuvers Loadings.......................................................................................... 71 Figure 45, Bending Moment Distribution........................................................................................ 72 Figure 46, Shear Moment Distribution ............................................................................................ 72 Figure 47C-shaped spars.................................................................................................................. 73 Figure 48, Wing Ribbed Geometry.................................................................................................. 74 Figure 49, Empennage Layout ......................................................................................................... 75 Figure 50, Flight Envelope Diagram ............................................................................................... 76 Figure 51, Landing Gear Geometric Considerations ....................................................................... 80 Figure 52, EIS Strategy.................................................................................................................... 81 Figure 53, sale number of current BizJets ....................................................................................... 82 Figure 54, Effect of Performance Parameters on Sales Number ..................................................... 83 Figure 55 Passengers Titles ............................................................................................................. 85 Figure56 RDTE cost break down for UniBee 620 ........................................................................ 88 Figure 57UniBee 620 Break-Even Point ......................................................................................... 90 Figure 58 UniBee 822 Break-Even Point ........................................................................................ 90 Figure 59 flyaway cost breakdown for UniBee 822 ........................................................................ 92 Figure 60 DOC break down ............................................................................................................. 94

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LIST OF TABLES Table 1, UniBee Family General Specification ................................................................................. 2 Table 2, RFP requirements ................................................................................................................ 9 Table 3: Balancing high-touch and low-touch ................................................................................. 17 Table 4. Major cities flight distance ................................................................................................ 19 Table 5. Mission Profile Characteristics .......................................................................................... 21 Table 6, Typical RFP Mission Requirements .................................................................................. 21 Table 7. Mission weight assumptions .............................................................................................. 22 Table 8. Merit matrix ....................................................................................................................... 24 Table 9. Functional comparison in scale of one to ten .................................................................... 24 Table 10 Engine Type Grading........................................................................................................ 24 Table 11. Uninstalled Thrust ........................................................................................................... 25 Table 12. Future Version Thrust ...................................................................................................... 26 Table 13 Total Thrust ...................................................................................................................... 26 Table 14. Engine Database .............................................................................................................. 26 Table 15. Functional comparison on scale of one to ten.................................................................. 27 Table 16 Merit matrix for engine parameters .................................................................................. 28 Table 17 Engine selection grading................................................................................................... 28 Table18 , Engine Specifications ..................................................................................................... 29 Table 19 Parameters affecting design objectives and their alternatives .......................................... 31 Table 20, Wing Geometric Specifications ....................................................................................... 32 Table 21, Flight-Deck Dimensions .................................................................................................. 35 Table 22, Flight-Deck Seat characteristics ...................................................................................... 35 Table 23Cabin dimensions .............................................................................................................. 36 Table 24, Cargo-bay Capacity Dimensions ..................................................................................... 37 Table 25 Subsystems ....................................................................................................................... 42 Table 26, Components Weight ........................................................................................................ 44 Table 27, required water quantities.................................................................................................. 45 Table 28, Drag Coefficient for Different Phases ............................................................................. 48 Table 29, UniBee SAS Gains .......................................................................................................... 51 Table 30,UniBee derivatives of case 2 ............................................................................................ 52 Table 31, UniBee620 Cruise Trim condition................................................................................... 53 Table 32 Material Properties ........................................................................................................... 68

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Designing a Cost-Effective and high Efficient Business Jet Table 33, UniBee General Loadings................................................................................................ 70 Table 34 A comparison among various landing gear configurations [3] ......................................... 78 Table 35 Merit matrix for landing gear selection ............................................................................ 78 Table 36 Landing gear ratings ......................................................................................................... 78 Table37 Landing gear size ............................................................................................................ 79 Table38 Landing gear loadings ..................................................................................................... 79 Table 40 UniBee Hourly Costs ........................................................................................................ 84 Table 41 UniBee Life Time ............................................................................................................. 84 Table 42, BizJets and Commercials Comparison ............................................................................ 84 Table43 Non-recurring cost reduction factors for Hornet 822 ....................................................... 87 Table44 RDTE phase costs ........................................................................................................... 87 Table45 Non-recurring development cost for UniBees ................................................................. 88 Table46 Break-Even Point ............................................................................................................ 90 Table47 flyaway cost for UniBee 620 ........................................................................................... 91 Table 48 flyaway cost breakdown for UniBee 620 ......................................................................... 91 Table49 flyaway cost for UniBee 822 ........................................................................................... 92 Table50 costs associated with flight for UniBee ........................................................................... 93 Table51 Maintenance Direct Operating Cost for UniBee ............................................................. 94

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1 RFP Overview The RFP states that both aircraft must meet some specific requirements which are described in Table 2. Table 2, RFP requirements

Requirements

Section

Opportunity/Background Business jets offer great value in travel with comfort.

7.7

Light business jets weigh roughly 13000-22000 lb.

5.1

Light business jets may have US coast to coast range.

4

New business jets offer larger cabins.

7.7

New business jets offer updated technology compatibility.

6.5

Business passengers expect comfortable and connected work environment.

7.7.8

Business passengers expect last minute and urgent trips on short notice.

4

Business passenger want to be able to travel to a wide range of destinations. Business passengers want to have jets with short runway operability.

4 5.2

Project Objective The EIS is 2020 for the first model and 2022 for the second.

14.1

A maximum cruise speed of 0.85 for shortening trip time.

5.2

Short take-off and landing field length for adding to operational flexibility.

5.2

Minimizing the development and non-recurring development costs.

15.2

Minimizing the acquisition and operating cost.

15.4.2

General Design Requirements Maximum Cruise Speed of Mach 0.85 at 35,000 ft.

4

Rate of Climb of 3,500 fpm

5.2

Service Ceiling of 45,000 ft.

5.2

Maximum Sea Level Takeoff Balanced Field Length of 4,000 ft. at Maximum Gross

5.2

Weight with dry pavement

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Designing a Cost-Effective and high Efficient Business Jet Requirements Maximum Landing Field Length of 3600 ft. at Typical Landing Weight

Section 5.2

Other Considerations Considering basic and optional features for a customer.

7.7

Considering unique features and a performance for marketing the aircraft.

14.3

Design Objectives Re-using of at least 70% of the airframe structure and systems by weight for both

2.2

but excepting the engine. Minimizing production cost by using appropriate materials and manufacturing

12

methods. Making the aircraft visually appealing.

2.2

Identifying what features are important to pilot, passengers and owners.

14

Making the aircraft maintainable and reliable.

11

For assuming technologies consider EIS for 2020 and 2022.

15

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2 DeBiz Design Space 2.1 DeBiz Design Approach DeBiz has decided to use V model for its design approach. Which has two sections (see Figure 1), the first one is designing and the second one is manufacturing, DeBiz proposal goes through the first section in detail. Generally speaking, V gives a breakdown through requirements in the first section then engages in problem solving by integrating in the second section. Every step of the second section has to be checked by the first section’s requirements in order to validate outcomes. All the design process in systematic approach starts with stakeholder requirements which are wage as they are expressed as customer and market desires which need to be converted to engineering requirements. Then there are some parameters that could be measured and be used as a function, In other words functional requirements. This process is called conceptual design in system semantics. Moreover, DeBiz needs to convert these functional requirements to physical requirements. Now a physic is needed in system to support all the functional requirements which are called preliminary design, DeBiz proposal ends with this phase. Next phase would be detail design which has not been considered in this proposal.

Figure 1, V model of system design

Some of these functional requirements have been given in the RFP, and some others came out from careful considerations of market and etc. DeBiz would follow up the Roskam method for its preliminary design [1] [2]. Furthermore, DeBiz has used task based Dependency Structure Matrix (DSM) to recognize design cycles and different disciplinary dependents. Below two task base DSMs have come. The first DSM illustrates the ability to cut off the feedbacks, therefore the design time would be minimizing. On the other hand, the second one gives us more 11 | P a g e

Designing a Cost-Effective and high Efficient Business Jet feedbacks which help to the integration. Therefore, DeBiz has chosen the first DSM in order to optimize the designing time. The chief designer administered to keep proper dependency between the tasks. Moreover, we must emphasize that the Task-Based DSM helped our team members to interact more efficiently while doing computations for both UniBee-620 and UniBee-822.

Figure 2, Task Based DSM Strategy Baseline

Figure 3, Lower Triangle Task Based DSM

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2.2 DeBiz Design Objectives DeBiz design objectives have been decided based on RFP requirements and environmental studies. Significant increase in range, takeoff and landing field lengths are the major design factors. Also the agility and highest level of comfort and luxurious withstand of beautiful appeal creates great market potentials. RFP requirements have led DeBiz to design two distinctive aircrafts with close to 70% commonality by weight. With extensive cost analysis a similar external configuration for both versions of UniBee seems to be the logical approach that allows sufficient commonality for manufacturing and acquisition cost reduction. It is clear that this decision leads to a heavier 6-pax version which needs to be certified under FAR-25. Such an approach, might seem to be against RPF, yet, it has many advantages such as cost-reduction. The very existence of commonality provides the opportunity to easily change between 6 and 8 seat versions. Moreover, market analysis justifies this decision in long-term basis. To make sure such commonality is mathematically understood, we have effectively used a combination of different DSMs 1 (Figure 4).

Figure 4, Physical DSM

1

Dependency Structure Matrix (DSM) 13 | P a g e


Figure 5- Parameter-based DSM

3 Environmental Study In this section, first the BizJets history introduced and followed up with its accidents study, finally the costumer analysis can demonstrate which airplane could have a great value in the market. The big opportunity is entrance with a high card and stay in the game of BizJets employing good future customer study.

3.1 History First jet fighter planes emerged in the waning years of WWII. Though the popular image is that Germany was the first to develop them, British pioneer Frank Whittle had drawing board designs of a jet plane as early as the mid-1930s. After the end of the war, commercial airlines quickly realized the value of these faster planes. Everyone wants to get where they want to go sooner. Less time in the air means less jet lag, less stress from engine and wind noise, and more time on the ground to take care of business. For upscale business travelers, those goals were first approached in the mid-1960s. In the 60s, airplane Manufacturing companies competed over the parameters of speed and range in design business jet. They tried to design aircrafts that travel farther more quickly. The competition was to seize the early market.

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Designing a Cost-Effective and high Efficient Business Jet In the seventies, the competition continued to gain more political and economic Support. About a decade after the cease of World War II the military's facilities were used for civil economic incentives. The support from the American government led the industry to a boost in manufacturing business jets. In the early eighties, Cessna's decision to enter the market in 1971 with a small, modestly performing low-priced business jet was a very risky one. As we have seen, a number of other companies had tried to market a low-priced business jet, and none had come close to success. Cessna with its intelligent products has gained control over the market in the little time It was since the 80s that Market competition intensified and production of the companies reach the maximum in quality. In our class Companies such as Embraer, Bombardier, Gulfstream, Dassault in the competition and Honda Be joined it in the late nineties. This competition includes a wide range of parameters such as speed, safety, comfort and beauty. In recent years due to growing demand, Competition in the market has become more complex. The need to leave the airport quickly, new sub-systems or new updates for older sub systems and Flying Safer, Things that should are a few things that should be considered in the design of future business jets.

3.2 BizJets Accident Study It is not possible to maintain in a great level of safety with no effort .Which means that business jet accidents must be studied to prevent them from happening. Results of these studies are summarized by the Figure 6 and Figure 7. 17

8 61

18

9

83

61

17

26

20 37

Landing Standing Taxi

5 4 10

Approach Takeoff Pushback

23

En route Initial climb

Figure 7, Accident Phase

25

Runway excursion

Loss of control

pilot & crew's

CFIT

hangar damege

Icing

Bird strike

Windshear

Other cases

Figure 6, Classification of Failure

Accident studies lead to identify functions which failed. DeBiz procedure for protecting UniBee is the use of “window of opportunity”. Any single function has been allocated to a physical element in order to propose confident backup in case of need. Recent accidents demonstrate that runway excursion in landing and losing control in takeoff are the most repetitive ones which could be prevented by decreasing takeoff and landing times.

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3.3 Customer analysis Customer study has been done to extract the customer demand and specifications who are rich luxury people who care about the self-acquisition and comfort. Luxurious has been defined to classify customers. Designing a new light BizJet and even surviving in the future market needs tomorrow costumer studies to find out which parameters helped us to succeed. Being luxury is an important feature in European and American markets from Maslow's perspective, it's about self-actualization. -

Luxury travel is growing faster than overall travel

-

North America and Western Europe account for 64% of global outbound luxury trips, despite making up only 18% of the world's population

-

Asia Pacific’s luxury travel market will see faster overall growth than Europe’s from 2011-2025, but will decelerate from 2015-2025

Travelers are defined by their behaviors and also by their varying levels of affluence. So they divided to the six group discussed in Figure 8.

3% %4 18%

%20

%24 %31

1. always luxury

2. special occasion

3. Bluxury

4. cash-rich,Time-poor

5. Strictly opulent

6. Independent & affluent

Figure 8, tomorrow’s Luxury Traveler’s Distributions

1. Money is no object at all for this traveler clan. According to many seeks, luxury is part of the everyday for them. Luxury is a minimum requirement rather than a perk, and an essential tool for making their life discreet, streamlined and comfortable. They will travel in first class or by private jet, stay in top‑level room categories and pay to outsource decision‑making to trusted parties. 2. They may use their loyalty points to upgrade their cabin class, to seek out prestigious dining experiences and to indulge in some well-deserved spa treatment. They may be willing to compromise on comfort at certain stages of their journey if necessary, or if it means they’ll get an incredible travel experience, such as sacrificing luxurious facilities to go on an independent guided tour of the Arctic.

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Designing a Cost-Effective and high Efficient Business Jet 3. This tribe blends Obligation Meeters with Reward Hunters. Their trip will have a business objective, but they will have the seniority and salary to extend their trip for some luxury leisure travel. 4. Members of this tribe won’t necessarily have an objective they need to fulfil during their travel, but they will have responsibilities that dictate when they can and can’t travel. Their plans often change at the last minute, so they may travel on flexible tickets. 5. Sharing their luxury holiday on social media is an important part of this experience – they want to be seen to be having fun, living life to the fullest and being able to indulge. 6. They may seek travel brands and destinations suitable for solo travelers, and may be looking for options that enable them to meet new people. They will want to feel that their travel provider is looking after them and helping them make the best choices for their trip, which could typically be a luxury yoga retreat in the Himalayas, or a cookery weekend in the South of France. An important facet of the luxury travel experience is how well travelers feel that their needs and preferences are understood by their travel providers. After knowing different kinds of luxury travelers it has been tried to know what they want in a journey. According to their requirements in a trip we divided them to two types: High-touch and low-touch travelers in Table 3. Table 3: Balancing high-touch and low-touch

High-touch travelers Value human interaction and like to be guided through the purchasing process to

Low-touch travelers Require little or no interaction when making a purchase

get the best options for their journey Will use technology in conjunction with

Use technology so they can self‑serve

personal service Are happy to be contacted (when it's useful) throughout their journey

Prefer not to be contacted during or after their time of travel

Low-touch luxury travelers may be too time-pressed for service that is heavy on interaction (as with the Bluxury and Cash-rich, Time-poor tribes). For high-touch travelers, this will be a minimum expectation, and a sign that they are being pampered and shown due attention. Strictly Opulent and Independent & Affluent luxury tribes tend to be more high-touch. As the result customer's specifications illustrated and will be considered for any single related section.

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4 Mission Specifications The RFP specifically requests for an aircraft that covers coast to coast range of the United States. However, it falls short to specify any cities on either coastline. It also requires the aircraft suitability for short time trips; while being able to cover a large set of destinations. A preliminary market analysis indicates that having an airplane with high cruise speed would be favorable. However, DeBiz firmly believes that such high cruise speed is, in fact, not necessary for all missions and destinations. The idea is to specifically tailor the combination of climb, cruise and descent phases for a specific payload and destination to compete in overall mission duration with existing business jets as the important criteria for businessmen is time. Considering these concepts leads to use of three capabilities as below because of needs and to have it more efficient it varies in any case Figure 9: A.

Terrain Avoidance (FA/TA):

The ability of living airport in low altitude and then climbing to higher altitude than normal transporters. It helps to departure at any desired time and climb to the determined corridor. B.

Cruise Climb

The ability to conduct cruise climb in higher altitudes which helps to initially climb to lower altitude in a shorter time and do the rest of it during cruise. C.

Continuous Descent Approach (CDA)

Altitude (*1000 ft)

The ability to conduct Continuous Descent Approach toward destination.

50

C

40 30 20

B

10 0

A

Figure 9. How the UniBee may use FT/AT, CC and CDA

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4.1 DeBiz Range criteria To select a standard range for UniBee, we have considered most of the cities targeted by businessmen. Table 4 illustrates over 50 major business routes and helped us to select the standard ranges for UniBee. Also Figure 10 shows distances between selected cities which are mostly below 2550nm, so it is our most important mission. Our goal is global coverage with a light BizJet. To cover intercontinental distances, we need to flight 3000nm, more reasonable selection for range is 3550nm which enlarge available routs. These two missions would be major missions for section 4.4. Table 4. Major cities flight distance

Departure

Destination

London

Madrid

London

Flight

Flight

Departure

Destination

676

Dubai

Berlin

2494

Stockholm

784

Beijing

Mumbai

2549

London

Rome

816

London

Ashgabat

2551

Rio de Janeiro

Buenos Aires

1078

Panama

São Paulo

2746

Beijing

Tokyo

1138

San Francisco

Panama

2885

Rio de Janeiro

São Luis

1202

new York

Lisbon

2926

San Francisco

Dallas

1298

London

Dubai

2952

London

Istanbul

1342

new York

São Luis

3003

London

Moscow

1367

new York

London

3006

Madrid

Stockholm

1407

new York

Paris

3150

Seattle

San Antonio

1550

Beijing

Dubai

3164

Washington DC

Mexico city

1622

Johannesburg

Dubai

3444

Sydney

Gerald ton

1906

new York

Zurich

3450

Moscow

Dubai

1963

shanghai

Dubai

3476

Washington DC

Los Angeles

2000

new York

Milan

3527

Washington DC

Seattle

2045

new York

Munich

3534

Seattle

Philadelphia

2092

Tokyo

new Delhi

3635

São Paulo

Ushuaia

2124

London

new Delhi

3655

San Francisco

Philadelphia

2213

Shanghai

Moscow

3678

Vancouver

new Orleans

2219

Shanghai

Moscow

3703

San Francisco

new York

2235

Tokyo

Moscow

4093

San Francisco

Miami

2268

Sydney

Tokyo

4133

Shanghai

new Delhi

2290

Seattle

Tokyo

4160

San Francisco

Boston

2341

Cape Town

Morocco

4200

Seattle

Miami

2367

Ashgabat

Tokyo

4200

Distance(nm)

Distance(nm)

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Departure

Destination

new York

Ketchikan

Flight Distance(nm) 2394

Departure

Destination

Dubai

Tokyo

Flight Distance(nm) 4277

Figure 10. World range map

4.2 DeBiz Mission Variations There is a trade-off between speed and range. So DeBiz introduces four primary missions to pass for both UniBees and take over the world with a light BizJet. Domestic flights in short time, continent coverage, cross-continent flights, and global delivery as will be explained. Domestic Fast Flight (DFF): Covering US coast to coast range and some other important routes like Berlin-Dubai will engage us to reach a flight range of 2550nm and NBAA IFR profile. And going fast with maximum passengers in any destinations up to 2550 nm is reasonably desired. Continent Coverage (CC): Covering America, Asia and Europe with a single flight is still tempting. America is too big for a light jet to travel one-legged, yet it will happen with a two-legged flight in a good selection of Table 4. Increasing range costs lower speed, lighter payload and more fuel. Cross-Continent Access (CCA): Cross-continent flight is the major restriction of world access, making it possible, will open large set of destinations for the costumer. Feasibility of this mission will support world come over with light BizJet too. Anyway it will cost more fuel and time which means decreasing payload and speed.

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Designing a Cost-Effective and high Efficient Business Jet Global Delivery (GD): Rising markets around the world has a temptation not to limit our environment to some near regions. Delivery and Support issues will cause making the airplane global access with least flight legs. A roughly 4200 nm range for fully fueled with extra fuel tanks can make it possible to every point with a tree-legged flight. First for reaching desired coast of America, second for crossing Pacific or Atlantic Ocean to a proper destination and final leg for the delivery that can be the longest trip.

4.3 Results Giving four missions (DFF, CC, CCA, GD) initial values and refining with weight sizing and sensitivity analysis across four variables: mission range, cruise Mach number, fuel consumption efficiency and airplane L/D final results illustrated in Table 5. Other quantities such as rate of climb, service ceiling and takeoff and landing field lengths are considered as RFP required values in Table 6. Table 5. Mission Profile Characteristics

Mission

Range

Alternative range

loiter

Payload

DFF

2450

100

30 min

2820

CC

3540

100

10 min

1820

CCA

3710

100

30 min

1420

GD

4280

100

30 min

0

Table 6, Typical RFP Mission Requirements

Rate of Climb

Service Ceiling

Max Sea Level Takeoff Balanced Field Length

Max Landing Field Length for Typical Weight

3500 ft./s

45000 ft.

4000 ft.

3500 ft.

4.4 Two Different Scenarios The major difference between 6 and 8 seat airplanes is the designed target market. Which this parameter firmly restricts block time and formal range for each UniBee thus affecting unit and operation costs. Thus DeBiz proposes an 8 seat airplane (UniBee 822) for business class operations which means it flight mostly domestic flights, suitable for the urgent travels and less than five hours’ flight needs less luxuries options for passengers.in other hands the 6 seat airplane (UniBee 620) designed for cross continental flights, this makes us to think about more comfortable flight, luxuries options and even shower for to be fresh after an 8-hour flight.

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5 UniBee Initial Sizing 5.1 UniBee Weight Sizing The weight-sizing technique is to estimate the maximum take-off weight of a new aircraft from its potential mission without having its external configuration. We have effectively used this technique to: 

Sensitivity analysis and parametric studies to adjust mission characteristics.



Adjusting airplane weights for different missions.



Deriving payload-range diagram

Obviously, the aircraft’s maximum 𝑾𝑻𝑶 depends on its𝑾𝑬 , 𝑾𝑷𝑳 , mission, reserved and trapped fuel and oil. With weight sizing and weight-sensitivity techniques, we have been able to verify the suitability of the selected mission profiles. This approach effectively helped us reach structural weight and from that to choose proper material, although this technique is straightforward, requires number of iterations to converge Table 7. Sensitivity analysis makes clear which parameters control our design, mission capabilities need that technological change and impact of selected parameters on mission characteristics [1]. Moreover, we used symmetric derivative to numerically compute sensitivity derivatives for proposed missions. Figure 11 Payload-Range diagram is another important outcome of this calculation. After several iterations we perceive that takeoff and empty weights are sensitive with L/D while changes in cruise Mach number does not have significant effect which demonstrates we should control fuel consumption and selected propulsion system [Ref: (UniBeeSensitivityTable)]. Table 7. Mission weight assumptions TOW

Range

Alternative range

Time

loiter

Payload

crew

Trapped Fuel and Oil (lb.)

21600

2450

100

5h

30 min

2820

2

1080

21600

3540

100

7h 10 min

10 min

1820

1

1080

21600

3710

100

7h 30 min

30 min

1420

1

1080

20800

4280

100

9h

30 min

0

2

1040

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UniBee Payload-Range Diagram 3000

Payload (lb.)

2500 2000 1500 1000 500 0 0

500

1000

1500

2000

2500

3000

3500

4000

4500

Range (nm)

Figure 11. Payload-Range diagram

5.2 UniBee Performance Sizing Consideration of performance objectives to pursue performance objectives and estimate related design parameters, indicates a valid range for wing and thrust loadings. As a result of this procedure, matching diagram Figure 12. Performance Matching Diagram used for UniBee and the optimum selected point should have the least distance from performance objective lines. Moreover in our design strategy less thrust loading and more wing loading is desired, so we could have more range and go faster with less fuel consumption and lower drag.

Figure 12. Performance Matching Diagram

Finally wing area and required thrust evaluates for UniBee Wing Design and UniBee Propulsion System & Integration.

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6

UniBee Propulsion System & Integration Considering the specific features of UniBee family, in this section we describe the distinctive

characteristics of the family Propulsion system.

6.1 UniBee Engine Type For UniBee family, we need to have a similar engine type. Therefore, we have divided mission phases based on their demand for energy and mission essentials. Obviously, we expect all mission essential functions and their energy demands are met and (Search for energy load profile). A specific merit matrix Table 8, has been developed to select the engine type for UniBee family; the most important of which are: 1- RFP requirements 2- Results from market survey and analyzing customer demands Table 8. Merit matrix Total

SFC

Noise

Engine Cost

Passenger Appeal

Engine Size

Propulsive Efficiency

Specific Weight

Maintainability

100%

16%

21%

6%

15%

9%

13%

8%

12%

Table 9. Functional comparison in scale of one to ten SFC

Noise

Engine Cost

Passenger Appeal

Engine Size

Propulsive Efficiency

Specific Weight

Maintainability

Prop

8

6

7

5

7

7

8

4

Jet

4

7

2

10

10

2

3

1

Fan

5

10

4

9

8

5

4

2

“Although RFP calls for business-jet, we must make sure that a turbo prop cannot pose as a serious competition” Table 9 employed to compare different engine types. Finally Table 10 demonstrates selected engine type. Table 10 Engine Type Grading Engine Type

Score

Defect

Turboprop

637

Mission Essential

Turbojet

525

Low Score

Turbofan

642

Selected!

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6.2 Number of engines Set of considerations listed below utilized for our decision process and we firmly concluded that in our class and weight twin turbofan engine satisfies required specifications. o o o o o o

Safety Issues General Configuration Required Trust Engine Weight Engine Location Operating Cost

6.3 Location Buried engine transfers noise and heat to the cabin section as well as its fire control issues so it is not a wise choice in our case. On the other hand, the podded beside the fuselage section installation offers better safety condition due to its separation from fuel reservoir and preventing ground suction. DeBiz has selected this superiority against podded under wing installation advantages. Near the fuselage installation gains more longitudinal stability and also decreases momentum caused by thrust arm than wing installed one. Also pusher engine suggests even more stability, required less elevator deflection and better handling in takeoff condition.

6.4 Thrust Calculations Having the exact values of thrust from UniBee Performance Sizing we can calculate uninstalled thrust consisting drag effect and subsystems load with the typical relation between installed and uninstalled thrusts. The additional thrust considered for required thrust of performance sizing used for subsystems e.g. electrical, pneumatically and mechanical Table 11. Calculations has been done using [3]. Table 11. Uninstalled Thrust

Required Thrust Uninstalled Thrust UniBee

8120lb

8850lb

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6.5 Future Versions Upgrading airplane design for future versions require additional thrust due to the upgraded subsystems, cabin technologies and avionics. 2025 as a near future studied and remarked for first upgraded model. Required thrust for all these changes noticed for engine selection thus further versions will cause no change in engines so it is much more cost effective and reasonable for manufacturing Table 12. Table 12. Future Version Thrust

Subsystem

Electrical

Mechanical

Pneumatic

Total

Required Thrust

140 lb.

80 lb.

0 lb.

220 lb.

Next generation electrical subsystems e.g. high-speed antennas, in-cabin visualization systems, rotating machinery seats, hostler robotics and updated avionics all need extra thrust in future. Finally selected engine should satisfy total value Table 13. Table 13 Total Thrust

Parameter

Required Thrust

Uninstalled Thrust

Required Thrust for future

Total

Quantity

8120 lb.

8850 lb.

220 lb.

9070 lb.

6.6 Engine Selection Now the target environment for the engines skipping several ranking and elimination procedures shortly comes in Table 14. Table 14. Engine Database Engine Model

SFC (lb./shp.hr)

Thrust (lbf.)

Weight (lb.)

Application

Company

TFE731-5

0.484

4300

852

BAe HS 125-800, Sabreliner 85

Garrett

TFE731-5AR

0.469

4500

884

Falcon 900, Falcon 20RE

Garrett

TFE731-40

0.457

4250

885

Falcon 50EX, Hawker 450

Garrett (AlliedSignal)

TFE73140AR-200G

0.46

4420

885

G150

Garrett (Honeywell)

CF700-2D2

0.643

4,315

767

Falcon 20E/F, Sabreliner 75A/80A

GE

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PW305A

0.388

4600

997

Learjet 60

Pratt Whitney Canada

RB.162-86

1.12

5250

520

Trident 3B (booster)

Rolls-Royce

CFE738-1-1B

0.372

5725

1325

Falcon 2000

CFE

ATF3-6A

0.44

5200

1125

Falcon 200

Garrett

TFE731-5BR

0.47

4750

899

Falcon 900B, Falcon 20RE, Hawker 800XP


TFE731-5BR1C

0.47

4750

899

Falcon 900C

Garrett (Honeywell)

TFE731-60

0.405

5000

988

Falcon 900EX


PW305B

0.391

5200

997

BAe (Hawker) 1000


PW306C

0.39

5600

997

Citation Sovereign


Engine selection again has been done employing merit matrix and airplanes popularity which used the engine beside pilots and airlines commentaries considered for this method. Also engine performance parameters and installation issues noticed as classification factors since satisfying required thrust has been used for elimination. Final results shortly have been demonstrated in Table 15. Table 15. Functional comparison on scale of one to ten Engine Model

initial cost

Operation cost

Ease of Assembly

Fuel consumption

Availability

Popularity

Thrust

TFE7315AR

8

7

9

7

9

7

10

PW305A

9

8

8

10

10

8

10

RB.162-86

6

5

10

2

8

4

5

CFE738-11B

6

5

2

10

8

6

3

ATF3-6A

8

7

5

8

9

6

5

TFE7315BR

7

7

9

7

9

9

8

TFE7315BR-1C

7

7

9

7

9

6

8

TFE731-60

7

7

8

9

9

6

6

PW305B

9

8

8

9

10

5

5

PW306C

9

8

8

9

10

7

3

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Designing a Cost-Effective and high Efficient Business Jet Since engine thrust is close enough to required thrust, it could reduce stability and control cost issues and also operates more fuel efficient. Moreover it will effect more properties consequently thus it has more value of interest. Every parameter of each engine rates with natural environment considerations, market requirements and airplane operating costs. Among all these parameters, bypass ratio is more important, while effects fuel efficiency and satisfies fuel required for long range flight and natural environment issues.

7800

thrust (lbf.)

6800 5800 4800 3800 2800 1800 150

250

350

450

550

650

750

850

speed (mph) h=0 h=27000 T=8120

h=9000 h=36000

h=18000 h=45000

Figure 13 Thrust vs Speed

Another major issue is accessibility which defines as maintenance facilities and accessories availability etc. in target countries of future market Table 16. Table 16 Merit matrix for engine parameters Parameter

Initial cost

Operation cost

Ease of Assembly

Fuel consumption

accessibility

Popularity

Thrust

Participation

12%

14%

11%

22%

4%

6%

31%

Table 17 Engine selection grading Engine Model

Point

Engine Model

Point

TFE731-5AR

835

TFE731-5BR

773

PW305A

926

TFE731-5BR-1C

755

RB.162-86

507

TFE731-60

726

CFE738-1-1B

545

PW305B

731

ATF3-6A

652

PW306C

657

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Designing a Cost-Effective and high Efficient Business Jet Finally, PW305A fits properly for this design and it is the best choice Table 17. Since engine selection is choice of customer and some additional situations may control it, we offer some alternative choices as redundancy of design which leaves the choice of engine for the airplane user. Thus, even if there is not Pratt & Whitney supporting material in a country, the user may decide which engine is proper for the case of usage. Obviously the higher score engine offers better operational conditions. Finally Table18 Table18 , Engine Specifications Company

Pratt & Whitney Canada

Overall Length

81 in

Type

PW305A

Height

45 in

EASA Type Certification Date

29 September 1995

Overall Diameter

36.5 in

Thrust

4600 lb.

Dry Weight

997.6 lb.

Thermodynamic Thrust

5800lb

Approximate Fan Diameter

31.1in

Service ceiling

51000 ft.

Bypass ratio

4.3

Specific Fuel Consumption

0.388 lb./hr.*lbf.

OPR

15.5

Stage Compressor

4-stage axial, single centrifugal

FPR

1.5

6.7 Selected engine benefits PW305A offers such benefits with its design and maintenance as discussed below. Fan Advanced shock management technology.FOD resistant titanium blades. Easily repairable or replaceable on aircraft Five-stage compressor 4-stage axial, single centrifugal. Integrally bladed rotors reduce parts count.Electronically controlled variable Inlet Guide Vanes (IGV) and bleed valves.Easy borescope access. Through-flow combustor TALONTM advanced technology impingement and diffusion cooled.Low emissions, high durability. Two-stage high pressure turbine

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Designing a Cost-Effective and high Efficient Business Jet High efficiency for low fuel consumption and long aircraft range.Advanced materials and cooling technology for long hot-end life.Built on the successful designs of the PW100 and PW4000 airline families. Three-stage low pressure turbine Free turbine, shrouded blades.High efficiency mixer for high performance and low noise. FADEC (Full Authority Digital Engine Control) Dual channel redundancy. Ease of operation, reduced workload.Intelligent health monitoring and diagnostics. Designed for efficient integration with aircraft electronics.

7 UniBee Configuration 7.1

UniBee General Configuration Selection

Based on 3.3 section, we should conduct specific maximum range with a light BizJet weight sizing and sensitivity analysis declared that L/D highly effects mission specifications. On the other hand SFC, bypass ratio and thrust are being controlled by engine which could not been changed a lot. As also we have to carry specific payload in the selected range, the best way to achieve this goal is to increase L/D. Since we want to have an agile BizJet which has more L/D than existing light airplanes. Using expert choice software the comparison between three configurations - conventional, three surface and canardhas been done. Stability, controllability, aerodynamic characteristics, cabin volume and visual appealing were derived our decision making. We have decided to have canard configuration which has better aerodynamic properties, stall characteristics and has simpler control linkages. First, it helps to move wing behind cabin to achieve better view for passengers during flight which is one of our major goals. Second, it causes simplification for pusher engine installation. Finally, this way we have undisturbed flow over control surfaces.

7.2 UniBee in critical weather conditions Based on the selected canard configuration and supercritical airfoil for wing we need to consider critical weather conditions as rain, haze and etc. Which causes flow to become turbulent in low speed during take-off and landing. Based on our calculations canard stall is safe and UniBee could recover. In wing section since turbulent flow causes drag rise we need to either carry more fuel or less flight range.

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7.3 UniBee Fuel Tank Since UniBee wing is located aft fuselage, so fuel consumption highly increases static margin to prevent this high effect we have decided to give an incidence to wing section which causes C.G. to travel slower. Since, as fuel consumes so the distance of remaining fuel increases. As the fuel pump is in the rearmost of fuel tank for this to work we have considered use of some hydraulic valve to make sure that fuel goes in one way, and there are always fuel to pump in different maneuvers.

7.4 UniBee Airfoil Selection Considering our initial design parameters to conduct high subsonic flights we need to have supercritical airfoil in root section to conduct more lift and less drag. Carrying most of the fuel volume and structural issues dictates us high thickness ratio. Yet, considering flight regime we are forced to have high sweep angle which causes wing elastic twist avoiding this leads to use thinner airfoil with less lift coefficient. We have selected NASA/LANGLEY MS (1)-0313 for root because of its 𝐶𝐿𝑚𝑎𝑥 , 𝐶𝐿 vs 𝐶𝐷 behavior and its negative 𝐶𝑚 − 𝛼 slope. For Tip PW51 was selected since it has steady 𝐶𝑚𝛼 mostly, superior 𝐶𝐿 vs 𝐶𝐷 behavior and low thickness ratio.

7.5 UniBee Wing Design 7.5.1 Wing Design Process Following considerations describe DeBiz basic logics in preliminary sizing of the UniBee wing layout: -

Priority is to make UniBee cruise speed faster than its rivals; while the take-off and landing field length are the same as rivals.

-

We expect not to use a new airfoil, unless computations show that it is absolutely necessary.

-

We further expect wing fuel volume would not force us to use a large wing-thickness-tochord ratio

Considering the aforementioned guidelines, we note how performance sizing chart Figure 12 leads us to the following options of Table 19: Table 19 Parameters affecting design objectives and their alternatives

Wing-loading (W/S)

Aspect Ratio (AR)

𝑪𝑳𝑻𝑶

𝑪 𝑳𝑳

𝑪𝑳𝒄𝒓

75

7.5

2.4

2.8

0.46

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Designing a Cost-Effective and high Efficient Business Jet Parameters given in Table 19 generally influence flight characteristics, stability and maneuverability, required structural strength in the intended Mach regime and finally required fuel-tank volume together with overall stall characteristics [4]. Obviously, in the process of reaching a suitable wing-layout, we need to repeatedly recalculate the airplane drag-polar and make sure wing C.G as well as aerodynamic center and finally the landing gears are in a correct position.

7.5.2 Results After several iterations, the final results are as given in Table 20. Table 20, Wing Geometric Specifications

Type

UniBee -8

Wing Area

305

Wing Span

47.8

Location

Low, Aft

Sweep angle (Λ 𝑐⁄4)

35°

Taper ratio

0.4

Thickness ratio

Root: 0.13

Dihedral angle

Tip: 0.08 3°

7.5.3 UniBee Wing Location Considering the general guidelines provided by [1] [4], we still believe UniBee to have a lowwing to avoid heavy frames imposed by mid-wing or high-wing configurations. Low-wing configuration is structurally simpler, lighter and provides good aerodynamic compromises. Furthermore low-wing technology helps decreasing interface drag and manufacturing costs. Nonetheless, low-wing generally leads to poor stall behavior or poor lateral stability. Such shortcomings are expected to be compensated with suitable Stability Augmentation Systems (SAS).

7.6 UniBee Wing Configuration Wing follows the canard configuration of UniBee which leads to a bipartite wing varying sweep angle and wing section. Inner part has high sweep angle and supercritical airfoil allows high subsonic flight and high lift generation while its high thickness will lessen the structure weight and provides proper volume for fuel tanks. The outer part that mainly operates as control surfaces part has a thin airfoil with zero pitching moment with a low sweep angle to avoid aileron reversal and aileron stall.

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7.6.1 Shape Parameters: Taper Ratio: Due to the wing lift distribution which tends to zero at tips the area is not very effective but decreasing chord increases stall chance at tip and control surfaces, light business jet database study demonstrates that they are all near a common value of 0.4 stepped taper ratio, it also has an optimum value with λ=0.4 for uniform span loading. In this case we assume𝜆 = 𝜆𝑖𝑛𝑛𝑒𝑟 × 𝜆𝑜𝑢𝑡𝑒𝑟 , and for avoiding tip stall it is better to have lower taper ratio. Dihedral: For low wing, positive 1-3 degrees dihedral improves spiral stability, in cost of some weight addition. So we choose 3° to satisfy desired spiral stability based on section Error! Reference source not found.. Wing Incidence on the Fuselage: Considering nose up and nose down cruise, will increase drag plus negative effects on comfort thus we firmly select 𝛼𝐶𝑙,𝑐𝑟𝑢𝑖𝑠𝑒 as the wing incidence angle. Twist: As previously discussed root and tip airfoils are different so we have geometric twist. Wingtip: Wingtips reduce drag by recovering flow of the wingtip vortex, which provides an effective increase in wing aspect-ratio and finally causes less fuel consumption.

7.7 UniBee Fuselage Design 7.7.1 Introduction DeBiz strategy for the fuselage forms from the inside out, which means we have started from the interior design. The RFP and also market clearly demands for a comfortable, high-tech and quite large cabin. Moreover, connected working environment is suitable for a set of our customers. Each of these parameters leads to a constraint for the fuselage dimensions. Fuselage sizing and selections are closely coupled with the cost, weight and drag factors and accordingly these are major limitations for our decision progress.

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7.7.2 Design Objectives DeBiz offers a light private jet for even large routes, so we came up with the idea to enhance the comfort level. In our design philosophy the comfort [5] defines as the available free space and adaptive environment that will support a wide range of applications from a straight entertaining room to a connected working area. Free space that noticed above means the available volume for moving around or rest in a seat place which we merely consider it as aisle height or leg room. Selective options all over the fuselage is compared as its function versus cost.

7.7.3 Nose Design Airplane’s forward fuselage integrates with the nose and its design has been done considering pilot’s comfort, placing related subsystems and finally exterior visual appeal. Classification Nose consists of flight-deck, nose gear, oxygen capsule and radome. Oxygen capsule should be placed in a safe location to prevent fire. Radar is located in radome which avoids perturbation and damage and is placed in the most forward location. Figure 14

Figure 14, DeBiz nose layout

Flight-deck Design Flight-deck and pilot seats are effected by an ordinary human body dimensions. Some essentials such as pedal to pilot seat and flight-deck seats distance and even entrance sizing are considered as

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Designing a Cost-Effective and high Efficient Business Jet major driving forces. Also comfort well thought out with pilot seat relocation and orientation besides pilot baggage behind the rear seat. Table 21 and Table 22. Table 21, Flight-Deck Dimensions

Dimensions

Length

Width

Height

Flight-deck

4 ft. 8 in.

5 ft. 2 in.

3 ft. 9 in.

Entrance

NAN

1 ft. 7 in.

3 ft. 9 in.

Table 22, Flight-Deck Seat characteristics

Seat Dimensions

Seat Degree of Freedom

Length

1 ft. 7 in.

Longitudinal Relocation

1 in.

Width

1 ft. 3 in.

Lateral Relocation

2 in.

Height

2 ft. 3 in.

Orientation Angle

15° (+5°)

Single Pilot Operation Market analysis revealed that single piloted flights would decrease cost and time due to reducing operational issues. Also lowering weight would let us carry more fuel or any miscellaneous weight. Copilot existence is not efficient during the most of flight time but the advantage is to lessen human work load and improving safety level. So DeBiz selected single pilot operation and offers a more intelligent avionic system instead. Avionic system Suggesting an intelligent avionic system is the matter of improving pilot situational awareness, convenient accessibility and operation which would provide desired level of safety for the UniBee flight. Improved autopilot technology will also reduce human workload preventing pilot exhaustion during 5 hour flights, which is DFF mission’s most duration. Desired avionic system should show a wide range of information in a small area on the pilot screen and effortlessly functioned. Furthermore air traffic, earth clutter, runway vision and poor weather perception should be shown. Facilitating flight procedure needs to reduce buttons, triggers etc. and bring them in a proper compact zone. It is important to be user friendly to avoid further difficulties. Weather awareness, storm tracking and turbulence detection are essentially needed for safety issues. On the other hand, traveling all over the world requires to be registered with both FAA and EASA regulations. Searching through existing models and considering risk study, cost analysis and weight importance we selected Garmin G5000 avionic system which meets our requirements while it has more reasonable cost and lower weight. Also, its release date (2015) avoids risky defects.

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Designing a Cost-Effective and high Efficient Business Jet Finally single piloted flight is safely possible with discussed topics. But since we are planning to go further ranges and do intercontinental or multi-leg flights which will increase travel duration, we have considered dual flight-deck settings to use copilot in case of need.

7.7.4 UniBee Cabin Dimensions Our strategy to enhance commonality is fixing the external dimensions for both UniBees. Key parameter for evaluating cabin dimensions is a typical human body size. Fuselage mid-section consists of two parts: subsystems area and cabin. Cabin height is measured to allow effortlessly move through cabin. Drag and weight issues do not permit us stand straight in the aisle but we can balance its height with environmental study. Aisle proper width In addition to seat sizes demonstrates a value for the cabin width. Besides, manufacturing and aerodynamic problems show circular cross section offers the best properties for the fuselage [6] [7] [8] [9].

Figure 15, Cabin Cross Section

Cabin length depends on various values discussed below. Seat arrangement, berthing and swirl capability, cabin tables, galley, shower and belted lavatory on its aft section Table 23. Fineness ratio as defined must have been set within 7-9 to lessen the drag in our class [2]. Table 23Cabin dimensions

Dimensions

Length

Max Width

Height

Fineness Ratio

UniBee 620

23 ft. 2 in.

5 ft. 9 in.

5 ft. 6 in.

7.8

UniBee 822

23 ft. 2 in.

5 ft. 9 in.

5 ft. 6 in.

7.8

Seats luxurious properties such as temperature control, massage system and leatherette skin, which gives it much attractiveness and comfort. Windows are important for the passengers, make the flight more joyful and visually appeal the airplane. Airplane door is the cabin stair itself, which reduces required airport services and lessens the operating cost.

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7.7.5 Galley and Full Refreshment Center Coolers, warmers, coffee maker, food and beverage water all placed in galley, wines and flavors placed in refreshment center in case of need. Both are located at the front of the cabin [10].

7.7.6 Shower and Belted Lavatory All designs of UniBee 622 enjoy a luxury shower, which its mechanism explained in stability & control section. Our exclusive property for a light BizJet is standing hot shower capability. Required height satisfies with removing aisle height from the fuselage and utilizing most of fuselage height, which is proper for a standing male with typical size. Wardrobe and lavatory located in front of shower near the emergency door. Moreover, the washstand is next to the shower. UniBee versatility allows replacing the lavatory with a structurally reinforced belted toilet to provide an additional passenger seat [10].

7.7.7 Cargo-bay Restricting baggage capacity for the RFP requested value, below dimensions is achieve. Table 24. Table 24, Cargo-bay Capacity Dimensions

UniBee 620 Dimension

UniBee 822

length

width

height

length

width

height

3ft.4in.

3ft.

3ft.

3ft. 6in.

5ft. 5in.

3ft. 2in.

Total Cargo-Bay Capacity

30.06

60.03

Total Cargo-Bay Weight

500 lb.

100 lb.

Cargo-Bay Door

length

width

height

2ft.6in

NON

1ft. 8in

The same as unibee620

The cargo-bay is sized to hold many kinds of cargo-bay. The cargo-bay dimensions satisfy stability and weight and balance but restrict cargo-bay to place above the wing. To solve this problem we have access to cargo-bay from cabin. The cargo-bay door is designed to open backward and is hinged from the bottom; the cargo-bay door is strong enough to hold a human weight. A telescopic ladder is put in baggage place to avoid dependency on airport services. According to the rule 14 CFR 25.857, there are six class of cargo-bay, which one of them is reserved. DeBiz baggage compartment is class A, and we have sufficient access to the cargo-bay from cabin.

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7.7.8 UniBee Interior design UniBee 620 is luxarry aircraft, which has an acceptable comfort for specified customers 3.3. UniBee 822 is more economic and it has less comfort options in comparison with UniBee 620. Based on Figure 16as shown below and our strategy in designing UniBee 620 and 822 , we decided to suggest three interior designs for UniBee 620 and one interior design for UniBee 822 , with a same configuration , to satisfy our customer demand and providing maximum comfort according to our space. It should be noted that all designs in owning wardrobe, kitchen, fullfreshment center ,lavatory and washstand are in common in all of below designs . The bathroom is specifically for UniBee620.

Figure 16. Based on “The Real World of Business Aviation” [11]

UniBee 822: Eight comfortable rotating chairs are the main facilities in this design. All chairs can rotate 45 degrees and the four middle chairs can rotate up to 90 degrees around a desk burried beneath the aisle floor will be unleashed and expand for such applications. This design presents a round area for better communication in business meetings.Also seats can berth 45 degrees and one can flat like a bed . So it provides a comfortable and a connected area at the same place. In this design galley and wardrobe are larger than UniBee 620 because of more number of passengers. Its wardrobe has capacity to fit items such as slack, slippers and etc. in it. Figure 17

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Figure 17, UniBee 822 Interior Design

UniBee 620: Because of more spacious room ,luxarious and different designs are reachable.

I: UniBee business design As RFP emphasised, connected work environment and comfort are the main objectives in this design which is satisfied by dividing the cabin capacity in two parts, working area and resting area. This design is suggested for businessmen. Figure 18

Figure 18, UniBee 620 Business Type Interior Design

II: UniBee Personal/Business design Six comfortable chair as explaind in H822 , and one standard bed are set to this layout. this design is suggested for both business and non business flight.Figure 19

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Figure 19, UniBee 620 Personal/Business interior design

III: UniBee personal design Comfortabe sofas and a massage room are the special feature for this design. For each passenger 29 inch space is considered in this sofa. This layout is recommanded for families, sportmen and those who seek for very comfortable flight. Figure 20

Figure 20, UniBee 620 Personal Interior Design

It is worth mentioning that all seats and sofas are equipped with safety belt and all of them are fixed in their places also the seats in design one can move slightly in rails to provide easier commuting. Becace of safety issues using bed and massage room is forbidden during take off and landing.

7.7.9 Entertainment and Technology We will make the travel more delightful for UniBee Passengers. Thus in addition to the conventional capabilities we recommend technologies below will perform a convenient private atmosphere. Each of which would be selective for the customers that will consequently change the price. 40 | P a g e

Designing a Cost-Effective and high Efficient Business Jet 7.7.9.1.1

In seat USB charger

7.7.9.1.2

Touch screen LCD on arm

Features internet connection, video game and movie, USB port, local network connection which the LCD itself located on the wall removable from its place. Specifications

7.7.9.1.3

Internet connection

Video game

Categorized movie collection

USB port

Local network connection

Removable LCD platform

Virtual Reality Glasses

One of the futuristic things that’s getting insanely popular all over the world, are the Virtual Reality (VR) videos. In case you’ve been living under a rock, a VR video is a kind of video that gives you a first-person visual experience giving you the impression that you are actually there at the scene. It also gives you a 360° sense of depth allowing you to look around in every direction you choose to look at. As a VR video is not the same as a conventional video, the guidelines for capturing a video, movement and placement of cameras are also different. 7.7.9.1.4

Fly-Fi

This advanced product solves in-flight internet speed plus its extensive accessibility. Small and light antenna is a matter of selection too. 7.7.9.1.5

IXION windowless jet The IXION windowless jet design concept utilizes flexible screens which cover the cabin walls and ceiling inside the aircraft. The screens display views captured from external cameras mounted around the aircraft to show the surrounding environment in real time, which can give the passengers the feeling of

flying through the air in an invisible airplane. With this setup, passengers can also conduct business video conferences, and presentations, watch state-of-the-art in-flight movies, or even project relaxing landscapes to change the feel.

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7.7.9.1.6

Sky Deck viewing dome

Foresaid items are selective for each of designs of UniBee 620 & 822 but this item can be selective just for second design of UniBee 620 & UniBee 822.In these designs two rear seat can stick together and climbing to the roof. This concept aims to give passengers an even better view of the skies than the pilot's by seating them on top of the plane, inside a transparent bubble-style canopy.

7.8 UniBee Subsystems In this section most important subsystems introduced in Table 25 and the major ones for the weight and balance illustrated in Figure 22. Table 25 Subsystems Location

Subsystem

Location

Subsystem

F-1

Oxygen Cylinder

S-2

Spoiler

F-2

Antenna

S-3

Differential Stabilizer

C-1

Fire Extinguishing

S-4

Elevator

C-2

Scape Slide

S-5

Winglet

C-3

Life Jacket

S-6

Canard

C-4

RAT(Ram Air Turbine)

S-7

Rudder

C-5

Mask Box

S-8

Trailing & Leading Edge Flaps

C-6

Life Raft

S-9

Trim Tabs

C-7

Water Tank

S-10

Actuator(servos)

A-1

Waste Tank

W-1

De-icing Boots

A-2

Hydraulic Power Unit

W-2

Electro-impulse Sys.(option)

A-3

Air Distribution Manifold

W-3

Thermal anti-icing Sys.

A-4

APU(Auxiliary Power Unit)

W-4

Chemical anti-icing Sys.

1

Accumulators

W-5

Inertial anti-icing Sys.(option)

2

Internal & External Lighting

W-6

Fuel Tanks or Fuel Bays

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Location

Subsystem

Location

Subsystem

M-1

Engine Driven Generator

W-7

Surge Tank(option)

M-2

Engine Fuel Controls(Throttle)

W-8

Fuel Pumps & Fuel Lines

M-3

Pressurization Sys.(shot off valve & check valve)

W-9

Fuel Venting System

M-4

Pneumatic Sys.(shot off valve & check valve)

W-10

Fuel Quantity Indicating System

M-5

Air Conditioning Pack

W-11

Fuel Management System (Tank Selection System)

S-1

Aileron W-12 Figure 21Brief List of Subsystems

Fuel Dumping System

Figure 22, Subsystems allocation

8 UniBee Painting and Finishing The main function of painting is to protect the integrity of airframe and keep away the components from corrosion rather than aesthetics. DeBiz has decided to consider the painting in the conceptual design, since it affects weight and CG position of airplane. The main expected function of the selected materials for painting is to be dust resistant. It can improve maintainability level and avoid skin friction drag rise and lift reduction. Nowadays, anti-dust paints are developing and we firmly predict that these materials could be a reasonable choice till 2020.

9 Weight Engineering Balancing airplane components has been done in this section and as the results, C.G. potato and components weights listed in the conclusion.

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9.1 Weights Breakdown Airplane components weights is listed in Table 26. Then using this parameters static margin adjusted for different missions of each airplane Figure 23. Considering under 800 lb. payload, causes 100 lb. ballast in the nose to keep handling quality in proper area. Table 26, Components Weight

Mass Weight Fraction (lb.) Component 10.00 2160 Nacelle Pylon Flight con. 0.00 0 Sys. Hydr./Pen. 13.00 2808 Sys. 1.32 285.12 Electrical 3.00 648 Radar

Component Fuselage Group ballast Wing Group Canard V-tail Group Nose Undercarriage Main Undercarriage Engine Engine Control Fuel Sys. Oil Sys. APU

Mass Fraction

Weight (lb.) 3.0

648

0.5

108

2.5 0.4 0.1

540 75.6 15.12

0.70

151.2 Avionics

1.0

216

2.50 9.00 1.50 1.50 0.50 1.00

540 1944 324 324 108 216

1.7 0.5 5.0 0.5 0.0 1.0

367.2 108 1080 108 4.32 216

ECS Oxygen Furnishing Miscellaneous Paint Contingency

22000 UniBee 822

21000

UniBee 620

Weight (lb.)

20000 19000 18000 17000 16000 15000 27.1

27.15

27.2

27.25

27.3

27.35

27.4

27.45

27.5

x_c.g. from nose (ft)

Figure 23, Weight-C.G. Excursion Diagram

9.2 Static Margin For airplane weight balance there are different methods which we have used both of them to be more accurate. First we have used BizJet data base for estimating component’s weight fraction then we corrected it based on size and volume of each component. Another important criteria is 𝑥𝑐𝑔 , 𝑧𝑐𝑔 and

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Designing a Cost-Effective and high Efficient Business Jet constraint of AC. Based on wing and canard position we could calculate airplane's aerodynamic center which is function of wing and canard so we have to control our static margin around 4-10 percent during flight. Based on decisions we had made we want to have stable static margin in takeoff ride through turbulence. During cruise we need less stability and finally we want to be agile in descent phase; thus we need to have greater static margin in takeoff while it should decrease to the least value for the landing. Based on what we have discussed we are going to arrange different parts, wing being the most important one. Since, it controls both aerodynamic center and CG move because of fuel tanks installed within. UniBee 620 and 822 behave a bit different for CG position due to the different payload, baggage and more specifically the shower in 6 seat version. This difference discussed more in stability section but the CG location for both airplanes adjusted for merely same static margin. Thus the handling quality for both airplanes. Now we have determined possible CG positions for five different points of a mission and different payloads which is fine adjusted. 3view illustrates CG valid Range.

9.3 Water Tanks The most important difference between our two versions is having stand up shower in 6pax version which is more luxurious. We have used this feature in balancing our airplane with pumping water through different tanks, water tank located under the cabin and waste tank in the aft section, thus we can control static margin during flight with a 3 lit per min pump. During flight passengers could use this shower with a rate of 9lit per min. In case of need another pump enters to the cycle. It has been calculated that this would not affect aircraft stability badly and it only helps agility during landing and if static margin goes to low the filter pumps would purify and transfer spoiled water to water tank. The amount of water needed for each passenger is 0.3 USG on average [Ref: Raskom vol 4, chapter 12]. Toilet flushing in aircraft need to use less water than the ordinary toilet flushing (0.5 gallon on average) so 0.3 gallon seems reasonable counting washing hands it increases up to 0.7 gallon (2.6 litter). Each passenger in a 5-hour flight needs lavatory two times on average, which is equal to 5.2 litter water. The water tank capacity is sized based on: 

At most, one of the passengers is able to use the bathroom.



The tank capacity is big enough to avoid filling after each flight.

Using purification system can reduce the volumes up to 1.5 litter/min. The quantities are as follows: Table 27, required water quantities UniBee 620

UniBee 820

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Primary amount of required water(lit)

219.2

50

Primary amount of waste water capacity (lit)

246.2

60

Amount of water after purification (lit)

200

45

Amount of waste water after purification (lit)

204

55

Percentage of water tank volume reduction

8.6%

12.9%

Percentage of waste water tank volume reduction

17.1%

20.3%

Business jets agility require as less airport services as possible. This purification system provides the water needed for the next flight.

9.4 UniBee 3View Figure 24 shows the final physic of UniBee.

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Figure 24, UniBee 3View

10 UniBee Drag Polar Since the geometry and size for any single component of airplane is specified, total drag of the airplane could be determined, which is divided to different terms: 

Parasite drag



Induced drag



Wave drag



Interference drag Parasite Drag

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Designing a Cost-Effective and high Efficient Business Jet Parasite drag includes zero-lift drag coefficient and drag increment from landing gear and flap deflection. Zero-lift drag coefficient calculation method proposed by [12] was used, which skin friction of each component exactly calculated from its geometry and size with the equation from [13]. Drag increment term forms during takeoff and landing due to the flap deflection and landing gear displacement and is approximated from [12]. Induced drag Lift production by wing and canard surfaces causes induced drag. Oswald factor calculated due to these lifting surfaces characteristics and simply induced drag calculated. Wave drag Flight at a specific Mach number higher than critical Mach number will cause wave drag relative to 𝐶𝐿 of each component. Wave drag coefficient calculated using [7]. Interference drag Flap generates significant part of interference drag when deflects during takeoff/landing and estimated using [3]. Table 28, Drag Coefficient for Different Phases

Takeoff

Cruise

Landing

𝐶𝐷𝑃𝑎𝑟𝑎𝑠𝑖𝑡𝑒

0.1702

0.0199

0.3592

𝐶𝐷𝐼𝑛𝑑𝑢𝑐𝑒𝑑

0.0108

0.0143

0.0112

𝐶𝐷𝑊𝑎𝑣𝑒

0

0.0035

0

𝐶𝐷𝐼𝑛𝑡𝑒𝑟𝑓𝑒𝑟𝑒𝑛𝑐𝑒

0.0053

0

0.0118

Discussed characteristics Figure 25 illustrates UniBee’s drag polar diagram.

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Drag Polar Diagram 3 2.5

CD

2 1.5 1 0.5 0 0

0.1

0.2

0.3 CL

0.4

0.5

0.6

Figure 25, Drag Polar Diagram at M = 0.85

11 UniBee Stability and Control In stability and control analysis of UniBee, discussions about the canard and vertical tail characteristics is done at first; then stability and control derivatives are calculated in two flight phases which were important and critical to UniBee. Then DeBiz checks ride qualities during those flight conditions.

11.1 UniBee Tail sizing canard sizing: for sizing the canard, static margin was checked to ensure longitudinal stability and we used the X-plot method for longitudinal stability in [14] the plot demonstrates the final iteration of UniBee’s static margin, which is determined to be 8% of the wing mean geometric cord.so the canard

28

X position

X cg 27.8

X ac

27.6

Desired canard Area

27.4 27.2 27 26.8 45

47

49

51

53

55

57

59

Figure 26,Canard CanardArea X- Plot

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Designing a Cost-Effective and high Efficient Business Jet Area is 46.69 ft^2. This value is below 10% different from the value which we calculated from table 8.5a in [14]. So we moved on with the calculated Area from the X-plot; Figure 26. Canard planform: canard aircrafts are sensitive to stall and stall proofing is an important issue. In order to avoid the aircraft from stall, the canard should stall first, so the constraints that satisfy this condition, illustrate the canard layout: AR: A large AR reduces the stall angle of attack, while a small AR does the opposite. Another benefit of the high AR is a steeper lift curve slope that produces higher lift at a given angle of attack. This allows for a smaller canard than otherwise and an installation at a lower angle of incidence. Otherwise high AR results in a short chord with a low Reynolds number. This may result in undesirable characteristics at low speeds, such as the formation of a laminar separation bubble. High AR canards are also sensitive to surface contamination. But even during take-off and landing the Reynolds number is higher than critical Reynolds number, so the flow will be turbulent during the whole flight and these problems won’t happen. Sweep: Sweepback will modify the lift curve slope in a similar manner as a reduction in AR. However, it will also tip load the canard and lower its stall angle of attack. We chose other design parameters of canard from table 8.13 [15] . The characteristics of the canard are in section [general specs]. Vertical tail: to size the vertical tail we used the X-plot method for lateral stability in [14]. So we calculated the vertical tail area to have the value 0.0573 rad−1 for Cnβ ; Figure 27. This calculated area has less than 10% difference from the calculated value from table 8.5b in [14] so we moved on with this value. Other design parameters are chosen from table 8. [14]. 0.13 0.11 0.09

Cn_beta

0.07 0.05 0.03 0.01 -0.01 45

50

55

60

65

70

75

80

-0.03 -0.05

Vertical tail Area Figure 27, Vertical tail area

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11.2 UniBee Derivatives For calculating stability and control derivatives, DeBiz uses the methods in [16]. UniBee Family longitudinal and lateral-directional poles for derivatives in 3 flight conditions (mid cruise where passengers could use stand up shower, end of cruise and landing) in terms of the system stability is checked. Because of derivatives in first case do not provide proper stability, they are adjusted and replaced with derivatives of second case.

11.2.1 Design Stability Augmentation System (SAS) To adjust derivatives and substitute with new values, SAS is used. Initial values derivatives with related SAS gains has been demonstrated in Table 29. And also, final values of adjusted derivatives case 2 are in Error! Reference source not found.. Table 29, UniBee SAS Gains Derivatives of case 1

SAS Gain

Cruise (Start of Shower Time)

End of Cruise

Landing

𝐶𝐿𝑢 =0.7597

-0.0708

*

---

---

𝐶𝑚𝑢 = -0.8455

0.0093

*

---

---

𝐶𝑚𝛼 = -0.6609

0.0093

*

---

---

𝐶𝑙𝛽 = -0.1302

0.0204

*

---

---

𝐶𝑙𝑟 =0.1574

-0.1587

*

---

---

𝐶𝑛𝛽 = -0.0370

-0.2032

*

---

---

𝐶𝑚𝑢 = -0.8455

0.0788

*

---

---

𝐶𝐿𝑢 =0.5593

-0.0027

---

*

---

𝐶𝑚𝑢 = -0.5476

0.0026

---

*

---

𝐶𝑚𝛼 = -1.2197

0.0057

---

*

---

𝐶𝑙𝛽 = -0.1771

0.0063

---

*

---

𝐶𝑙𝑟 =0.2338

-0.0219

---

*

---

𝐶𝑛𝛽 =0.0759

-0.0128

---

*

---

𝐶𝑚𝑢 = -0.0082

0.0004

---

---

*

𝐶𝐿𝑢 =0.0330

-0.0284

---

---

*

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𝐶𝐷𝑢 =0

0.0182

---

---

*

𝐶𝑚𝑞 = -12.8441

-0.1896

---

---

*

𝐶𝐿𝛼 =5.1497

-0.0068

---

---

*

𝐶𝑚𝛼̇ =-0.5135

-0.4328

---

---

*

𝐶𝐿𝛼̇ =0.2214

-0.0922

---

---

*

Table 30,UniBee derivatives of case 2 Derivatives

Cruise (Start of Shower Time)

End of Cruise

Landing

𝐶𝑙𝛽

-0.11

-0.1100

-0.2022

𝐶𝑙𝑝

-0.4897

-0.4707

-0.4655

𝐶𝑦𝛽

-0.7370

-1.0503

0.3019

𝐶𝑙𝑟

0

0

-0.9982

𝐶𝑦𝑝

-0.0821

-0.0226

-0.0358

𝐶𝑦𝑟

0.2226

0.4504

0.4104

𝐶𝑛𝛽

0.1100

0.1100

0.0573

𝐶𝑛𝑝

-0.0221

-0.0511

-0.1026

𝐶𝑛𝑟

-0.0597

-0.1426

-0.1234

𝐶𝑙𝑑𝑟

0.0484

0.3086

0.2300

𝐶𝑙𝑑𝑎

-0.0231

0.0319

0.0600

𝐶𝑦𝑑𝑎

0.0739

0.2118

0.3777

𝐶𝑛𝑑𝑟

-0.0030

-0.0251

-0.0678

𝐶𝑛𝑑𝑎

-0.353

-0.0770

0.1359

𝐶𝐷𝑢

0.2526

0.2526

0.4000

𝐶𝐷𝛼

0.3135

0.2442

0.5397

𝐶𝐷𝛼̇

0

0

0

𝐶𝐿𝑢

0

0

0

𝐶𝐿𝛼

6.9997

8.45

5

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𝐶𝐿𝛼̇

0.3379

0.2941

-1.8000

𝐶𝐿𝑞

3.1933

8.5378

5.7288

𝐶𝑚𝑢

0

0

0

𝐶𝑚𝛼

-0.5609

-0.0406

-1

𝐶𝑚𝛼̇

-0.8553

-0.669

-10

𝐶𝑚𝑞

-15.8449

-17.3719

-17

𝐶𝑚𝑑𝑒

0.0708

0.8089

0.5865

𝐶𝐿𝑑𝑒

0.0280

0.3555

0.1394

𝐶𝐷𝑑𝑒

0.0021

-0.0141

0.0083

Now, according to new set of stability derivatives, trim condition parameters are in Table 31, UniBee620 Cruise Trim condition. Table 31, UniBee620 Cruise Trim condition T (lbf)

δelevator (rad)

α(rad)

UniBee620 Cruise Trim Condition

2956

-1.26

-0.01

UniBee620 End of Cruise Trim Condition

2556

-0.07

0.00

UniBee Family Landing Trim Condition

608

-0.08

0.00

11.3 UniBee 620 Ride Quality System during Cruise Unibee620 has an incredible feature which allows passengers to take shower in the last hour of cruise. Since passengers are more likely to take shower as they are closer to airport DeBiz have decided to use this feature in the last hour of cruise. In this case gust alleviation system activates. Design challenge is as airplane gets affected by gust the person who is taking shower would not get injured. Schematic of this scenario in shown in Figure 28.

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Figure 28, Unibee620 Cruise in presence of gust

For this purpose, the ride quality criteria are used to ensure that the controlled aircraft will provide passenger comfort to an acceptable level. Ride quality specifications express vertical acceleration should be limited to ±𝟎. 𝟎𝟓 𝒈 and lateral acceleration should be limited to ±𝟎. 𝟎𝟐 𝑔 [17].

11.3.1 Ride Discomfort Index A ride discomfort index has been proposed in the specification MIL-F-9490D: 𝐽𝑅𝐷 =

2 𝐼𝑦𝑦 −𝑆 𝐶𝑚𝛼 𝑀𝑤 = 𝑐̅ 𝜌 𝑥𝐴𝐶 𝑊 𝑈0 𝑊 𝑥𝐴𝐶 (𝑥𝐴𝐶 𝑖𝑠 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑓𝑟𝑜𝑚 𝑡ℎ𝑒 𝑎𝑒𝑟𝑜𝑑𝑦𝑛𝑎𝑚𝑖𝑐 𝑐𝑒𝑛𝑡𝑒𝑟 𝑡𝑜 𝑡ℎ𝑒 𝑐. 𝑔. )

It is generally agreed that a ride discomfort index less than 0.1 means that there will be very little, if any, degradation of a passenger’s comfort. DeBiz checks it for longitudinal channel. If it does not get passed, we have to use RCS active control to minimize JRD. There is no corresponding ride index for lateral motion, although it is known that human beings are more sensitive to the effects of lateral acceleration. If it is required to reduce the level of lateral acceleration occurring at some specific aircraft condition, a control system is provided. The system usually has been designed to minimize the r.m.s. value of 𝑎𝑦 [18]. Now since we have a design cycle, DeBiz has decided to develop a simulator instead of using optimal methods. With extensive trial and error and designing different types of controllers and using handling

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Designing a Cost-Effective and high Efficient Business Jet quality criteria and considering the results, DeBiz could get better outcomes. Below transfer functions and perturbation models and other required data in this design process have been described.

11.3.2 Dryden Wind Turbulence According to [19], the forcing function generating the requirement for a Ride Quality Augmentation System (RQAS) is atmospheric turbulence. One of the various mathematical model have been used in the various turbulence model consideration for analytical use is Dryden model [15]. This model is used in our gust simulation.

11.3.3 Transfer Functions Gust-input transfer functions

β(s) ay c.g. (s) , βg (s) βg (s)

and control-input transfer functions

β(s) ay c.g. (s) , δ(s) δ(s)

are

given in [16]. 𝐚𝐲

𝐀𝐜𝐜

The accelerations are measured by an accelerometer located ahead of the missile cg at bathroom position (e.g. ay

Acc

(.

These accelerations are summation of ay

CG

and Tangential acceleration.

Tangential acceleration is equal to the angular acceleration β̈ multiply by the radius of the rotation (X CG − X acc) [19].

Flying quality Requirements: Cruise (CR) flight is in category B and Unibee620 in cruise is in class II. The flying quality requirements of MIL-F-8752C are presented for level 1 of flying qualities. Computing Ride Index for UniBee620 Longitudinal Motion: By substituting parameter’s value in ride index equation for longitudinal motion we have: 𝐽𝑅𝐷 = 0.0993 < 0.1 Due to above discussion about ride discomfort index values, this value is appropriate for longitudinal motion in gust condition. In our scenario, a passenger goes to bathroom in cruise phase for 1 hour while for 10 minutes aircraft is affected by turbulence. In addition to above analysis for ride discomfort index in longitudinal motion Since human beings are more sensitive to the effects of lateral acceleration, our analyses are going to focus on ay

Acc

response

to gust input, then if it does not satisfy the ride quality specifications mentioned in pervious section, DeBiz has designed control system for gust alleviation.

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Designing a Cost-Effective and high Efficient Business Jet Design Active Ride Control System (RCS) _ Regulator: Block diagram for gust alleviation system is presented in Figure 29 u(s) R command(s)

+

C

-

y(s)

P

Figure 29, Gust alleviation sys. Block diagram

Where C and P are the Controller and Plant, respectively. In our model U(s) is ayβgust (s) and Y(s) is ayTotal (S) = ayβgust (s) + ayδ (s). Also Rcommand(s) is considered equal zero. In this section, using Dryden model and modeling disturbances in cruise altitude which allows passengers taking a bath, disturbances are applied for 600 seconds and then equivalent dynamic response of linear disturbed model that are shown in Figure 30 are evaluated. The important point is about few atmospheric disturbances in this cruise altitude which can be seen in model applying this disturbance model, the unibee620 will deviate slightly in acceleration and side angle (β) during bathing time. Since comfort of the person in the bathroom is essential and to assure that these disturbances will not affect any more in other turbulence conditions, DeBiz assumes a scenario in which the aircraft is under β disturbance of 0.01 radian. In this case DeBiz will design a controller to alleviate acceleration resulting from that in the place of bathroom where there is no seatbelt or safety equipment for the passenger. The basis of this design is to follow the zero command ay

Acc

in bathroom and to reduce its

r.m.s value. Results based on β Gust input and controller response for two models of Dryden input and Step input are available in Figure 31 and Figure 32respectively. Checking Unibee620 Cruise (Start of Shower Time): Lateral-Directional poles are stable but have little values (Dutch Role and Spiral), therefore, in the first place we tried to design 3 specified controllers (that are illustrating in Figure 30) using logic of handling quality criteria and investigate various results. As shown in the following Figure 31 and Figure 32, the controller No.3 has got the best results and reduced the disturbed input acceleration (ay (ay

Acc

Acc

response to β) that is added to output acceleration

response to 𝛿). As in the Figure 31for Dryden input it could be claimed that while the responses

are inconsiderable, this control system subtracted the order of acceleration by 1 time. Clearly, r.m.s. value of 𝑎𝑦 is minimized. Also for step input of 0.01 rad as shown in Figure 32 the lateral acceleration is below 0.02 g in the starting of gust and then resets to zero.

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Figure 30, Active Control ride quality sys.

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Figure 31, 〖a_y〗_Acc/β_g, β/β_g ,r/β_g ,φ/β_g responses 〖〖,a〗_y〗_Acc Total, R.M.S. and Error results for Dryden gust model

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Figure 32, Total ay and r.m.s for three controllers, step gust input

Checking UniBee 620 End of Cruise: Fuel is being consumed during shower time, so inertia moments changes has been calculated 10-12% of total inertia moment. This causes a change in route locus. Considering of this issue, in this section to assure that the passenger can use the bathroom until the end of cruise phase, when the aircraft’s derivatives are changing simultaneously and to test operation of third designed controller, we applied final cruise condition to simulator while the Dryden perturbed model is used to model disturbances based on aircraft’s speed.  Computing Ride Index for Longitudinal Motion at End of Cruise By substituting parameter’s value in ride index equation for longitudinal motion We have:

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Designing a Cost-Effective and high Efficient Business Jet 𝐽𝑅𝐷 = 0.0083 < 0.1 Like before, this value is appropriate for longitudinal motion in gust condition at end of cruise. In this stage, Unibe620 used controller No.3 which was the best one for alleviation of lateral acceleration resulting from gust.  Responses and Active RC Controller Results ay

Acc

,

βg

β βg

,

r βg

,

φ βg

responses , ay

Acc

Total, R.M.S. and Error results for Dryden model input, are

shown in Figure 33. -4

- Gust-Dryden Modele @ Cruise Altitude

2

-(rad)

# 10

0

# 10

- to - gust response

-3

0

-

gust

(rad)

5

-5

-2 0

500

1000

1500

2000

0

500

time(sec) # 10

? to - gust response

-3

2

r(rad/sec)

? (rad/sec)

2

0

-2

# 10

500

1000

1500

1500

2000

0

2000

0

500

# 10

a y to - gust response

-3

1000

time(sec) 1

# 10

-3

Total a y time history (RC Sys. 3)

y

Total a (g)

y

a (g)

2000

r to - gust response

-3

time(sec)

0

-5 0

500

1000

1500

0

-1

2000

0

500

time(sec) # 10

-3

1000

1500

2000

1500

2000

time(sec)

R.M.S. of total a y (RC Sys. 3)

1

error

1

0.5

# 10

-3

Error (RC Sys. 3)

0

ay

r.m.s

1500

-2 0

5

1000

time(sec)

0

-1 0

500

1000

1500

2000

time(sec)

0

500

1000

time(sec)

Figure 33, 〖a_y〗_Acc/β_g ,β/β_g , r/β_g , φ/β_g responses, 〖a_y〗_Acc Total, R.M.S. and error results

Clearly, atmospheric disturbances are in the order of10−4. Also lateral acceleration is in negligible order of 10−3 . Therefore, using controller, amplitude of response of lateral acceleration to βg will reduce in contrast with condition without controller in the beginning of disturbances and finally will reset to zero. DeBiz is going to increase the order of βg input and use step model of 0.005 rad to assure the designed controller works in this scenario well so did.

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Designing a Cost-Effective and high Efficient Business Jet Figure 34 is showing the responses and satisfied condition of ride quality for lateral acceleration. These investigations revealed that system could be kept on during bath time.

Figure 34, β_g step input, 〖a_y〗_Acc Total and R.M.S. results

Discussion: As discussed above it is logical to have shower time in last hour of cruise. So as weight reduces at the end of cruise and unibee620 gets more susceptible to gust, and outcomes of this designed system which were better than expected, DeBiz had decided to consider this system for rest of the cruise and results came out acceptable. In designing the ride quality system, DeBiz has to consider stand up shower water flow. As water starts to flow in stand up shower, inertia moments changes has been calculated 5% of total inertia moment. This causes a slight change in route locus. Yet, still described model works good based on result analysis. Since using this system consumes lots of energy, it only starts to work as shower door opens. So we need to have a switch to get the required feedback to the control system. This switch has to be considered in electronic systems.

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Designing a Cost-Effective and high Efficient Business Jet Ide quality system does not need dual redundant control system in perturbed condition with Dryden model. Yet, considering more gust effects leads to use of dual redundant system to be more conservative. This system has been placed between rudder and avionics, for inspecting this system we have decided to put a hole.

11.4 UniBee Family Ride Quality System during Landing Due to improper Phugoid damping in landing, the next challenge is to evaluate the UniBee family’s stability during landing in presence of gust. To do so, DeBiz will assume UniBee in landing phase while it faces horizontal gust. Schematic of this scenario in shown in Figure 35.

Figure 35, Unibees landing in presence of gust

In order to model the gust, based on NASA document [20] for aircrafts with the speed of 107 m/s in Landing condition, step input of 1.87 ft. /sec is used (for both horizontal and vertical speed), DeBiz will apply input of 5 times greater than mentioned amount to the aircraft with the landing speed of 120.9 ft. /sec in step form for 1200 seconds. For better modelling of disturbances, DeBiz used Dryden model which is applied to perturbed equivalent dynamics for 300 seconds during landing phase. According to Ref. [20] about gust alleviation control system of a STOL airplane in the landingapproach condition, ‘’The important forcing terms and the resulting response may be reduced to relatively small values by use of flaps with suitable aerodynamic characteristics, a rearward center-ofgravity location, and gearing of flaps to spoilers or other drag devices to reduce longitudinal force changes due to flap deflection. The stability characteristics of the alleviated airplane appear to be unsatisfactory without stability augmentation to provide pitch-attitude stabilization and improved damping of the Phoguid mode.’’

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Designing a Cost-Effective and high Efficient Business Jet Considering this fact, DeBiz could use this approach. Yet, because of TCQ (time-cost-quality) DeBiz have decided to use another approach as below. θ(s) for g (s)

DeBiz approach is to consider perturbed transfer functions to horizontal velocity gust u

better

effectiveness as well as excitation of Phoguid mode with horizontal speed as input, investigate responses and then try to design a controller using pitch angle transfer function to control surface input for the truncated Phoguid equations of motion. DeBiz accounts aircraft’s perturbed transfer function response to gust for the truncated Phoguid perturbed equations of motion in this model. Meanwhile, DeBiz tries to improve Phoguid damping mode during landing. Pitch rate feedback gain is used to move the Phoguid poles towards with higher damping ratio. Discussed transfer functions

θ(s) ug (s)

and

θ(s) δ(s)

are

given in Ref. [3]. Finally, the gust effect alleviates by controller. Also this controller fixes the pitch angle during landing in presence of disturbance. This analysis can also repeat for the response of disturbed transfer function of θ to vertical gust. Considering costs and also little CG travel this system is usable for both UniBee versions.

11.4.1 Design Regulator System for gust alleviation The output θ and the aircraft’s response to velocity-gust as input u(s) are added up. DeBiz intends to control the result (e.g. y(s)) with designed system. Following Figure 36 contains linear simulator of perturbed dynamics with gust-input models as well as designed autopilots.

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Figure 36, Pitch attitude hold system to alleviate aircraft response to horizontal gust velocity

Inner Loop Analysis (Pitch Damper of Pitch Attitude Hold Systems 1 and 2) The magnitude of the break frequency ‘’a’’ of servo is an indication how fast a servo react to an input command. Typically, it is assumed that the break frequency of servo is 10 or 20 rad/sec. The higher the break frequency increases cost of the actuator. So DeBiz decides to use break frequency of 5 rad/sec for servo then, analyzes roots locus of open loop transfer function of inner loop (e.g. pitch damper). For gain equal to 0.0149 for pitch damper loop, Phoguid damping increases as well as real part of poles and phase margin is proper for inner loop to achieve stability.

Outer Loop Analysis (Pitch Attitude Hold System 1) The corresponding close loop damping ratio with 𝐾𝜃 = 0.37 for outer loop gain, meets the damping requirement of handling quality for Phugoid response and gain margin has improved while its Phoguid damping (𝜉𝑃𝐻 = 0.471) is still greater than when previous undersigned system. Step Input Horizontal Gust Velocity, 𝜃 response and Gust Alleviation System 1 Results in Figure 37:

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Figure 37, θ response and gust alleviation system 1 results, step input horizontal gust velocity

Clearly, as shown in Figure 37, the amplitude of pitch has quickly reached the amplitude of 𝜃𝑐𝑜𝑚𝑚𝑎𝑛𝑑 in landing.

Outer Loop Analysis (Pitch Attitude Hold System 2) In this stage, DeBiz has increased Phoguid damping and use first order low-pass filter in outer loop in order to damp Dryden disturbance. (Time duration of applying disturbance is 300 seconds) For gain equal to 1.21 for outer loop, Phoguid damping increases (𝜉𝑃𝐻 = 0.681) as well as real part of poles while both of phase and gain margin have got better values. Dryden Input Horizontal Gust Velocity, 𝜽 response and Gust Alleviation System 2 Results in Figure 38:

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u gust (ft/sec)


Horizontal Gust Velocity-Dryden Modele

50 0 -50 0

200

400

600

800

1000

1200

800

1000

1200

1000

1200

1000

1200

3(rad)

time(sec) 3 to u gust response

0.2 0 -0.2 0

200

400

600

3(rad)

time(sec) 3Total (Pitch Attitude Hold Sys. 2)

0 -0.1 -0.2 0

200

400

600

800

3error

time(sec) Error (Pitch Attitude Hold Sys. 2)

0.1 0 -0.1 0

200

400

600

800

time(sec) Figure 38, 𝜃 response and gust alleviation system 2 results, Dryden input horizontal gust velocity

As shown in Figure 38 the amplitude of θ has reached the 𝜃𝑐𝑜𝑚𝑚𝑎𝑛𝑑 in landing with negligible error.

11.5 Discussion By means of necessity Pitch attitude hold system should be dual redundant. In addition obviously it is not cost-effective to introduce different pilot trainings. Considering Figure 23 from weight engineering which demonstrations not a significant change in CG position, thus not an inherent change in moment of inertia. Thus masking strategy helps us to first make the canard configuration ride like conventional ones. Second two different airplanes do not need different trainings.

12 UniBee Structural Design 12.1 Introduction Structural design main approach has to satisfy: 

Loads exerted on aircraft according to defined missions



Minimum weight



Minimum Cost

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Designing a Cost-Effective and high Efficient Business Jet Before composites introduce to the market, metals has been used in aircraft manufacturing. Composites has increased aircraft performance with less weight and sufficient strength. Since composites are expensive, designers are forced to use less. At first composites were used in control surfaces and secondary structures. Marketing, price reduction and advancement of technology expanded their usage in aircrafts. Therefore, in airplanes such as A350-XWB more than 50% of structural weight is composite, In smaller aircrafts even more percentages is belong to composites[1]. Figure 39 demonstrates trend and forecast of Carbon Fibers usage [2]. Also it could be predicted from Figure 40 that composite prices both manufacturing and raw materials costs would be decreased 20% with respect to 2014, which allows to use more composites[2].

Figure 39, Trends and Forecast for Material

Figure 40, Manufacturing and Process Cost

Another advantage of composite is less fatigue under swinging loads, which results in increasing of aircraft segment’s life. Increasing of composite usage has been resulted in production rate increase and

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Designing a Cost-Effective and high Efficient Business Jet it has forced manufacturers to look for less flaws and higher rate [3]. It is predicted by the year 2020, the composite usage in aircraft increases up to more than 50% in aircraft structure, due to: 

Dramatic composite usage growth



Increment in composite utilization becomes economical.



Price reduction needed according to world economic recession.

Due to 100% commonality in structure of both UniBees, composites could be used more than 50% which has some benefits as below: Aircraft weight decrease up to 10% 

Aircraft performance promotion



Long-time Maintenance expanses frugality[3]



Acceptability of high-tech composite materials Application and customer satisfaction can upgrade the UniBee’s market share in competition with metal aircrafts.

12.2 Material selection As mentioned before, metals such as aluminum, steel, titanium and composites like CFRPs are the main materials in aircraft structure. Some parameters in material selection is mentioned below: 

Various properties of materials in different functions



Common usage of each material in specific segments by experience



Cost reduction



Availability of manufacturing methods

For example, Aramid has been used mostly in impact resistant parts. Different composites as Glass series, Aramid, and CFRP has been used in UniBee structure, and also steel, aluminum 7075 and 2024 which is very common in aerospace industry Table 32. Demonstrates these three materials mechanical properties. Table 32 Material Properties Material

Tensile Strength

Modulus of Elasticity

Density

Cost

Aluminum

65-75 ksi

10 Msi

0.1 lb/in3

Medium

Steel

180-280 ksi

25-30 Msi

0.3 lb/in3

Low

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Carbon Fiber

75-300 ksi

10-33 Msi

0.05 lb/in3

High

UniBee uses various materials as shown in Figure 41 and Figure 42 for different parts of structure.

Figure 41, Internal Parts Material

Figure 42, External Shell Material

12.3 UniBee loading and v-n diagram An important part of aircraft load analysis is consideration of loading conditions in critical situations in terms of load factor and speed limit based on FAR25, which consists gust loads. V-n diagram shows: 

Determination of aircraft Speed and maneuvers limitations according to rules



Determination of maneuvers allowed area besides structural design constraints

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Designing a Cost-Effective and high Efficient Business Jet Considering unity of both UniBee structure and design based on FAR-25, Figure 43 illustrates the v-n diagram of UniBee, which is extracted by principal specifications and dive speed of UniBee considered about 320 KEAS.

Figure 43, UniBee V-n Diagram

12.4 Primary sizing estimation according to critical maneuvers All defined maneuvers in airworthiness standards have to be studied in structural detail design. Aircraft critical maneuvers selection is difficult. Some maneuvers are selected as the prime factors to achieve a primary estimation of aircraft main parts dimensions. For example, pull up maneuver leads to bending moment in aircraft wing. It can be said that all other maneuvers are passed when the spars (wing bending main supporters) sizing is done based on pull up maneuver, which has been done with 1.5 safety factor. Some important loadings and different conditions that affect structural design are explained in Table 33.[4] Table 33, UniBee General Loadings

Flight loads

Ground loads

Other loads and conditions

Maneuver

Vertical load factor

Jacking

Gust

Braking

Pressurization

Control deflection

Bumps

Crash

Buffet

Turns

Actuation

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Designing a Cost-Effective and high Efficient Business Jet Flight loads

Ground loads

Other loads and conditions

Inertia

Catapult

Bird strike

Vibration

Arrested landing

Lightning strike

Aborted take off

Hail

Spin-up

Power plant

Spring back

Thermal

One wheel/two wheel

Fatigue

Towing

Damage tolerance

Ground winds

Fail safety

Break away

Acoustics Ground handling

The main maneuvers based on experiments, are explained in the rest of this section and schematically presented in Figure 44. [4]

Figure 44, Special Maneuvers Loadings

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Figure 45, Bending Moment Distribution

Figure 46, Shear Moment Distribution

12.5 UniBee Structural Layout Decisions in structural design have been made based on parameters which support main design goals. For instance, in wing design the number of spars could be one, two, three and even more. Sizing could be done by design parameters. Number of spars does not affect weight a lot to be a critical factor. Desired redundancy is the most important factor in determining the number of spars in respect to being economic. Except cost and weight, all structural parameters are dependent to the mission, which need to be achieved with appropriate weight, reasonable cost and suitable reliability.

12.5.1 Wing Wing is the most important part of aircraft structure, which generates lift and carries fuel. Two overall spars have been used in UniBee’s wing structural design. Considering pressure distribution of wing in critical maneuvers, the main spar is located 20% of chord and the rear one at 65%. Also locating rear spar was determined based on considerations has been made for flaps, ailerons and their mechanical

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Designing a Cost-Effective and high Efficient Business Jet systems. Moreover, landing gear attachment to the wing root with respect to wing geometry, causes an auxiliary spars to be located 15% of wing root due to bear torsion. The minimum distance between ribs is 24 inches, which due to load distributions along the wing, increases up to 38 inches in tip. The rib spacing is a task accomplished during the detail design phase with Finite Element method. Selecting the largest possible rib spacing would reduce weight and simplify assembly. Furthermore, the spars, as shown in figure, have variable cross sections. Since torque box is located between two primary spars and the wing has been made of composite, a free space has been reserved for future UniBee version’s leading edge devices. As UniBee has only an auxiliary spar neat root, whole cross sections have been filled by ribs. DeBiz has decided to place wing below fuselage to prevent cabin volume be wasted, for this purpose it is needed to extend frames to the spars. In the Figure 47, cross sections of spars have been illustrated. These are designed based on composite manufacturing process.

Figure 47C-shaped spars

C-shaped spars are used due to: 

Easier production than I shaped one with composite manufacturing methods



Almost same properties as I shaped one

Besides, on airfoils cross section some curvatures are designed to lighten and increase their strength properties. Besides, on airfoils cross section some curvatures and holes are designed to lighten and increase their strength properties [7]. Each rib is formed so it has a rib flange, but these are used to bond the rib to the skins and spars, forming a solid structure [5].

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Figure 48, Wing Ribbed Geometry

Flap dimensions leads to use of flap tracks beneath it to connect to the rear spar, in order to hold the flaps.

12.5.2 Fuselage Fuselage loads are due to wing, landing gear, motor and cargo loads and some aerodynamics forces plus internal pressure in pressurized sections in high altitude. Therefore, fuselage has some duties such as: 

Shell for shear stress bearing



stringers for bending moments and axial forces



frames and bulkheads for distributing concentrated forces and maintaining the fuselage shape

DeBiz has decided to use metal for the first versions’ fuselage and refine it to composite in future. In the first versions, DeBiz has used conventional aluminum semi-monocoque fuselage structure that consists of hoop-frame rows and stringer in order to connect to each other. Some frames are placed over the fuselage with more supports than others, such as wing spars connection frames, vertical tail, canard, motor mounting to fuselage and some frames considering the aircraft segments arrangement. Podium available in cabin for chairs arrangement is designed by auxiliary structures, which connect to the frames.

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Designing a Cost-Effective and high Efficient Business Jet The average distance among metal frames are nearly 20 inches which are connected to each other by 16 stringers. The number of hoop-frames decreases in composited future versions and reduce the fuselage structure weight about 20%. Pressurizing the fuselage is done by 14CFR Part 121 Air Carrier Certification requirements. Pressure bulkheads are placed before cockpit and aft cargo section.

12.5.3 Vertical tail and canard Vertical tail structure has been chosen to be composite with two spars in 15% and 65% distances, that is connected to the empennage frames and the ribs are between two spars. Ribs distances in vertical tail is a little bit more than wing and is nearly 22 inch in tail root, which in tip, is about 32 inch. Each rudder needs 25% cord that is attached to the backward spar. Design considerations in tail structure results the minimum structural weight. Figure 49 show the cross sections and tail structure.

Figure 49, Empennage Layout

Canard has been designed like the wing and its composite is same. Ribs are in 24-inch distances. Two spars are in 25% and in 70% distances. Canard stability is important so DeBiz has located two spars in its structure in order to: 

Increasing redundancy



Simpler elevator connection mechanism to backward spar

It is worth mentioning that using one spar has less weight but two spars are chosen because of the mentioned benefits.

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12.6 UniBee Flight Envelope The flight envelope is defined as the territory in which the aircraft could fly safely inside various limits. The flight envelope is defined by Mach number, altitude, limited load coefficient, and other variables. The envelope boundary is related to the aircraft stall, thrust, and structural limits. Figure 50

Figure 50, Flight Envelope Diagram

13 UniBee Landing Gear Selection 13.1 Design Approach Two attitudes has been considered for design of landing gears. First is considering restrictions such as: 

Forces and Moments



Stability considerations during taxi, takeoff and landing.

And order a new design based on our requirements. Second attitude is to select from existing landing gears and changing some design parameters reverse engineering, that reduces the cost of manufacturing [Ref: cost]. As it was discussed in previous sections First jet fighter planes emerged in the waning years of WWII. Though the popular image is that Germany was the first to develop them, British pioneer Frank Whittle had drawing board designs of a jet plane as early as the mid-1930s. After the end of the war, commercial airlines quickly realized the value of these faster planes. Everyone wants to get where they want to go sooner. Less time in the air means less jet lag, less stress from engine and wind noise, and more time on the ground to take care of business. For upscale business travelers, those goals were first approached in the mid-1960s.

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Designing a Cost-Effective and high Efficient Business Jet In the 60s, airplane Manufacturing companies competed over the parameters of speed and range in design business jet. They tried to design aircrafts that travel farther more quickly. The competition was to seize the early market. In the seventies, the competition continued to gain more political and economic Support. About a decade after the cease of World War II the military's facilities were used for civil economic incentives. The support from the American government led the industry to a boost in manufacturing business jets. In the early eighties, Cessna's decision to enter the market in 1971 with a small, modestly performing low-priced business jet was a very risky one. As we have seen, a number of other companies had tried to market a low-priced business jet, and none had come close to success. Cessna with its intelligent products has gained control over the market in the little time It was since the 80s that Market competition intensified and production of the companies reach the maximum in quality. In our class Companies such as Embraer, Bombardier, Gulfstream, Dassault in the competition and Honda Be joined it in the late nineties. This competition includes a wide range of parameters such as speed, safety, comfort and beauty. In recent years due to growing demand, Competition in the market has become more complex. The need to leave the airport quickly, new sub-systems or new updates for older sub systems and Flying Safer, Things that should are a few things that should be considered in the design of future business jets. BizJets Accident Study huge rate of accidents is due to landing gear failures. Different scenarios had been considered and selected landing gears have been revised. Due to these two reasons DeBiz has decided to use the second method.

13.2 Types Before landing gear selection, selecting desired landing gear type was required. Based on our data base which is collected from 20 random selected business jets, it was found out that they had all used tricycle type. This type is outranked in comparison, because of structural and geometrical features, and is more successful in safe takeoff and landing. It has also the best performance during taxi and the best stability on the ground after the quadricycle type.

13.2.1 Tricycle and its advantages Since one of the most important functions for UniBee is fast and safe takeoff and landing. DeBiz was leaded to choose tricycle type. Some important features of this type has been brought as below: 

Less bounce after touch-down.



Good acceleration during T-O due to lower AOA.



Hard braking on main wheels cannot cause the airplane to nose over.

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Designing a Cost-Effective and high Efficient Business Jet 

Airplane pitches nose-down upon main gear touch-down, reducing lift.



Shorter wheelbase permits light turning radius.



Easier to land and, thus, more forgiving for inexperienced pilots.



Good forward visibility because of low deck angle.



Floor deck angle on the ground is closer to being horizontal, making passenger entry and exit easier.



Dynamically stable on the ground so it is easier to maneuver.



Good ground control in crosswinds. Table 34 A comparison among various landing gear configurations [21]

Quadricycle

Bicycle

Single main

Human leg

Multibogey

Tail gear

Nose gear

Stability on the ground

10

2

1

5

8

7

9

Stability during taxi

10

3

2

0

9

1

8

Take-off/landing run

5

4

3

2

8

6

10

Cost

2

7

9

10

1

6

4

Manufacturability

9

4

3

10

1

5

7

Aircraft weight

9

4

3

1

10

6

7

10: best, 1: worst

Considering design methods and some requirements such as cost, fast takeoff and landing, DeBiz evaluates each parameter. Manufacturability is less important because of selecting from existing landing gear designs. Moreover cost, takeoff and landing Specifications are the most important factors. Table 35 Merit matrix for landing gear selection

Stability on Stability the ground during taxi

Takeoff/landing run

Cost

Manufacturability

Aircraft weight

Total

18%

27%

24%

5%

11%

100%

15%

Table 36 Landing gear ratings

Type

Quadricycle

Bicycle

Single main

Human leg

Multibogey

Tail gear

Nose gear

Score

657

421

393

445

634

538

760

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13.3 Landing gear selection Based on landing gear data base for business jets with similar takeoff weights as UniBee (21000lb), landing gear triangles have been formed which have leaded to some forces and moments, that helped in selecting UniBee landing gear. These calculations have been resulted in selection of Learjet 75’s landing gear. The applied forces on Learjet 75 landing gear wheels accommodate DeBiz requirements with 1.5% accuracy. Landing gears are designed to bear up to 25% more load, to be capable of using in next versions.

13.4 Landing gear model and its location DeBiz landing gears are retractable. The main gear is placed under the wing and up in the embedded space between wing and fuselage and the nose gear is located under the fuselage and up under the nose.

13.5 Design parameters Landing gear selected geometric data has been illustrated as below. Table37 Landing gear size Parameter

quantity

Parameter

quantity

XLG(Main gear) from Nose

28.45ft

HLG

3.05ft

XLG(Nose gear) from Nose

6ft

Wheel base

22.45ft

α(to)

12.50

Wheel track

8.9ft

α(c)

200

X cg – XLG(Main gear)

1.27ft

H(clearance in takeoff rotation)

1.18ft

X cg – XLG(Nose gear)

21.18ft

Applied forces and its quantity is shown below: Table38 Landing gear loadings Parameter

Quantity

F nose(min)

5450N≈5.5KN

F nose(max)

6200N≈6.2KN

F main(min)

89900N≈89.9KN

F main(max)

90700N≈90.7KN

F dyn(main)

9960N≈10KN

F dyn(nose)

8270N≈8.3KN

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FMAIN(total)

100660N≈101KN

FNOSE(total)

12500N≈12.5KN

It should be noted that the main forces are equal to the sum of the two parts and the forces that applied to main gears are equal to the half of the quantity in table above.

Figure 51, Landing Gear Geometric Considerations

14 DeBiz Market Analysis In this section market strategies has been discussed, then it continues with sale estimations and market making.

14.1 DeBiz Market Strategy The entry into the service should be 2020 for the first model based on 0

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Designing a Cost-Effective and high Efficient Business Jet RFP Overview section. Semantics of DSM employed to illustrate how two different models are used to refine each other due to the 95% part commonality by weight Figure 52. Which is a result of countless hours of engineering analysis of DeBiz and it is mainly about the feedbacks and feedforwards generated during the first years of operation that has been demonstrated from DSM below.

Figure 52, EIS Strategy

Since DeBiz is entering to the market as a new company, it is required to be the best design ever as it is going to introduce DeBiz. So UniBee 620 has been chosen to enter first. As Figure 52. Demonstrates that after UniBee 620 enters to the market in 2020 its feedbacks help to refine the decisions have been made for UniBee822 which is going to introduce in 2022. This process will be done for UniBee620 in 2024 with feedbacks from UniBee822.

14.2 DeBiz Sale Estimation DeBiz strategy for estimating the number of sales is a statistic survey; 8 performance parameters of some adversary aircrafts have been considered by trial and error method. Those 8 parameters are:

1. Range (4 passengers)

5. Baggage space capacity

2. Cabin Volume per Passenger

6. Unit price

3. Maximum cruise speed

7. Hourly Operating Cost

4. Takeoff Distance

8. Passenger Capacity.

The main idea is that better performance leads to more sales number. Then, a function is needed to connect these performance parameters to sales number. It is needed to collect a database of the same business aircrafts. This database includes BizJets' names, their performance parameters and their number of sales per year. DeBiz market agents have been tried to form a non-linear equation to connect performance parameters and sales number by using this database. Genetic Programming is an automated method and optimization tool that can be used for this objective. GP generates functions by using performance parameters and functions like power, 81 | P a g e

Designing a Cost-Effective and high Efficient Business Jet summation, Division, Multiplication, and Logarithm and so on randomly and finally converges to the desired function by using genetic algorithm.

If the information is correct, exact, and large enough, it is possible to estimate a nonlinear sale function. In the following, DeBiz presents the behavior prediction of the market by generated function.

Figure 53, sale number of current BizJets

As shown in the Figure 53, the generated function follows the aircraft behavior acceptably. Clearly there are lots of parameters which affect product sale which has not been considered in this model such as Brand effects, company marketing abilities, financing and etc. An accurate market analysis needs modeling of these parameters for better decision-making. The procedure has been described with present function considering DeBiz TCQ. In the Figure 54, the actual data behavior and function estimated for each performance factor has been illustrated.

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Figure 54, Effect of Performance Parameters on Sales Number

Market team strategy is analyzing sensitivity of the generated nonlinear functions about the design point (UniBee operational parameters). UniBee 620 and UniBee 822 operational parameters are demonstrated in the following sections.

14.3 DeBiz Market marking (Making New demand) It was sale estimation according to sale rate of aircraft in previous periods and the past behaviors of the market that was explained in previous section. Future study, has to try for attracting the markets that can increase sale rate and every important event occurs in the world, also are parameters that affect sale rate. In this section it has been tried to convince some special first class cabin's customers to use BizJet instead and is tried to answer these two questions: 

How can DeBiz persuade first class customers that BizJets are more suitable for them?

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Designing a Cost-Effective and high Efficient Business Jet 

According to the process that was adopted in response to the first question, aimed at attracting to this market how much will add to the sales?

Looking at the growth of demands of first class travel over the last few years, especially in America, shows that not only it has not been destroyed, but also has it been increased. The strategy of DeBiz design team for attracting this demand is based on covering the customer needs. The biggest difference is in the prices at the first sight. It is better to classify the cost of the ownership of BizJet or the cost of using them in order to study these differences in prices perfectly properly. Table 39 UniBee Hourly Costs Hourly Traditional Ownership Cost

Hourly Fractional Ownership fee(1/2 interest=500hours in year)

Hourly Charter Flight Fee

Hourly Typical First Class Price

2864$

3063$

2450$

467$

All numbers in the table above have been calculated according to the numbers in the chart below and common management prices that have defined by companies which charter BizJet or handle fractional program Table 40. Table 40 UniBee Life Time UniBee life cycle

UniBee unit price

UniBee hourly operating cost

10000hours

6928600$

2172$

Comparison indicates that prices for chartering UniBee or participating in its fractional program are less than other common aircrafts which are doing them. It does not mean being the best if the price of chartering is less than others; because the prices mentioned above includes initial prices. These hourly prices stay fixed for 10 years for who wants to buy all or some fractions of UniBee while the cost of chartering changes because of the change in annual rate of inflation. Also, it should be considered that the price of chartering changes when the seasons change and it may become less or more according to the demand. Now it is possible to answer the first question. The table below indicates 3 significant differences between BizJet and commercial aircrafts Table 41. Table 41, BizJets and Commercials Comparison productivity

Saved time

Ability to use secondary airports or airports with infrequent or no scheduled airline service

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Business aircraft

4h

71%

80%

Commercial aircraft

2h

31%

19%

voted percentage by passengers

15.4%

58.3%

26.3%

For calculating the value of using a BizJet, all 3 parameters mentioned in the table above have been converted first into time and then into cost to persuade the customers that how much they can save their time and make a profit on using a BizJet. Saved time has been estimated based on take-off distance, cruise speed, ground time before flight, arriving time to airport differences between UniBee and a usual commercial aircraft. Average saved time for using a business aircraft in one trip is 5 hours. It has been considered in converting time into cost that according to the poll by (Ref) the majority of passengers are typical managers and how much they are paid per an hour Figure 55.

Figure 55 Passengers Titles

Annual typical Manager Salary

117990$

A UniBee passenger needs to fly over 60 hours in order to offset the increased cost of using UniBee instead of using first class by considering a typical manager's salary and by considering that a journey takes 5 hours in average.

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Designing a Cost-Effective and high Efficient Business Jet All that airliners pay attention to is passenger's comfort to attract first class passengers but only cost has been discussed up to here. However, UniBee competes with the best and the most luxurious first classes in the world on cabin amenities, is discussed in the interior design section. According to the statistics that has been releases by (Ref) luxury travel is successful in covering all ranges but has more growth in Long-haul and Border-trip. Taking a look at UniBee Missions once more shows that UniBee has been designed to cover all ranges and then it can compete with a commercial aircraft. It needs to know how many first class booking have been to answer the second question. Checking Domestic First Class Flight in the USA indicates why RFP emphasizes covering all the USA; because this chart shows demand congestion that has been covered by airliners due to poor performance of BizJet manufacturer companies. Hornet can cover all this section; it also can compete with airliners in International First Class Flight because of its long range. The primary goal of DeBiz design team is to sell 5 UniBee per month. Forecasts do not predict this number of sale because they are based on previous behaviors of BizJet sales. Studies show that it is needed to attract only a small percentage of first class demand to achieve the desired number of sales.it needs efficient advertising models just like that was explained in the answer of first question and proper finance for customers.

15 DeBiz Life Cycle Cost Analysis 15.1 DeBiz Cost estimation Costs estimation is required for attracting customers with low hourly operating cost and unit price. The lowest design and manufacturing cost along with acceptable quality is noteworthy in all parts of this proposal. RFP specifically asks to reduce operational cost by appropriate materials and method selections, which supports production rate in month. These items are briefly explained in structure section. All the calculations in this section of this proposal has been done based on Roskam method [22].

15.2 Non-recurring development costs Costs of RDTE phase included research, development, evaluation and test that is explained below.

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15.2.1 Research DeBiz has decided to use available technologies in design and manufacturing so research expenses have considered to be zero.

15.2.2 Development, test and evaluation In order to estimate DTE phase costs which includes engineering, certification, production tooling, facilities and labor [22], method is used. In this method, MTOW, maximum cruise speed and Nrdte (the number of aircrafts that is going to be manufactured in RDTE phase) is needed which primary parameters are driving cost in Roskam method. DeBiz has decided to have 3 aircrafts for flight test and 2 for static test, so 5 aircrafts is going to be manufactured in RDTE phase. To convert each cost element from 2017 to 2020 for UniBee 620 and UniBee 822 with 3% constant inflation rate assumption in each year, future value for each cost element is calculated.

15.3 DeBiz RDTE cost comparison for Hornet and UniBee Based on Table42 a factor has been introduced for reducing costs due to commonality in RDTE as below: Hornets had 75% commonality, so for calculation of RDTE cost of Hornet 822, it would be multiplied by factors below. Also, based on design objectives, section 2.2, 95% commonality between 2 aircrafts causes zero RDTE cost for UniBee 822.because of that, the half of UniBee 620 RDTE cost has been considered for both 620 and 822. Table42 Non-recurring cost reduction factors for Hornet 822 RDT&E Cost element

Engineering

Development Support

Material

Tooling

reduction factors

0.3

0.5

0.3

0.05

RDTE phase costs43 Table

RDTE cost($)

Hornet 620

Hornet 822

UniBee 620

UniBee 822

294640000

169260000

163035000

163035000

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Designing a Cost-Effective and high Efficient Business Jet As it can be seen the UniBee 620 RDTE cost has been become half of Hornet 620 because of the 95% commonality. In Table44 , UniBees RDTE cost can be seen in detail. Table44 Non-recurring development cost for UniBees Cost element

Man-hours

Rate $/hour

Total cost($)

Engineering

709670

90

63,870,000

Development Support

-

-

5,330,100

engine

-

-

3,800,000

avionics

-

-

2,250,000

manufacturing

1,604,500

75

120,340,000

materials

-

-

8,404,200

tooling

1,334,400

80

106,750,000

Quality control

0.13× manufacturing

80

16,686,800

-

1,012,300

Flight Test Aircrafts

Flight Test Operations

Total Non-recurring Cost

326,070,000

RDTE cost distribution for UniBees are illustrated in.

Figure56 RDTE cost break down for UniBee 620

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15.4 DeBiz Flyaway costs Manufacturing costs analysis has been represented in this part of proposal. Table46 illustrates the Flyaway cost elements which are estimated by labor rate per hour in America. Cost reduction is possible with making contract with foreign companies, which have lower manufacturing labor rate per hour. It has been considered that reducing labor rate causes an increase in quality control costs. Since less experienced labor needs more afford on quality control.

15.4.1 Break-Even Point Analysis To get the total number of program airplanes, finding the break-even point is necessary. Which shows that there are no advantages or disadvantages for the company. Table 2 represents total production cost which has been calculated based on Roskam method [22]. To find out the break-even point. First, program cost versus total number of aircraft program curve has been drafted then with 10% and 13% profits assumptions, the program cost is multiplied by 1.1 and 1.13 coefficients, so related costs to these profits and total number of program production in program would be drawn. Assuming the total aircraft price to be 6 to 11 million dollars, the income diagram has been drafted. According to figure, it is clear that as the unit price increases, the program number of airplanes is needed to pass the break-even point decreases. Obviously in first years of sales benefits would be possibly not satisfying. Yet, over the years by marketing and advertising, the higher profit margin is going to be achieved. The following charts are obtained by assuming production rate of 5per month. DeBiz has to produce at least 275 UniBees in two years to start achieving profit, maximum 2 years after production program, according to UniBees market entrance. It has been calculated that when the 7 million$ unit price meets the 275 production number. It leads to the production of 11airplanes per month. Increasing production rate to 11 could not be supported by cost program and market. Also, its necessary facilities are expensive and not economical. Both UniBees unit prices are illustrated in tables 2 and 3 by assuming 350 production numbers which have at least 10% profit. According to monthly production rate of 5 for both UniBee620 and UniBee822 production program will survive in market for 6 years.

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Figure 57UniBee 620 Break-Even Point

Figure 58 UniBee 822 Break-Even Point Break-Even Point45 Table Flyaway cost($)

Unit price($)

Hornet 620

1755900000

7,518,500

Hornet 822

2266500000

7,655,200

UniBee 620

2156300000

7,355,400

UniBee 822

2161600000

7,305,900

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Designing a Cost-Effective and high Efficient Business Jet As discussed in interior design section DeBiz has decided to have its UniBee 620 to be more luxurious, which causes more interior design costs. It is assumed 15000$ interior manufacturing cost for UniBee620 per passenger and 10000$ for Unibee822. Table46 flyaway cost for UniBee 620 Cost element

Man-hours

Rate $/hour

Total cost($)

Engineering

1,604,500

90

92,889,000

Airplane Program Production Cost

engine

-

-

271,480,000

avionics

-

-

157,500,000

manufacturing

14,976,000

75

1,002,900,000

Interior

-

-

69971,000

materials

-

-

237,460,000

tooling

1,334,400

80

166,030,000

Quality control


80

155750000

-

55953000


Total Flyaway Cost

2244700000

Unit Cost

6879200

Unit Price Table 47 flyaway cost breakdown for UniBee 620

7567100$

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Designing a Cost-Effective and high Efficient Business Jet Table48 flyaway cost for UniBee 822 Cost element

Man-hours

Rate $/hour

Total cost($)

Engineering

1,604,500

90

92,889,000

Airplane Program Production Cost

engine

-

-

271,480,000

avionics

-

-

157,500,000

manufacturing

14,976,000

75

1,002,900,000

Interior

-

-

36,735,000

materials

-

-

237,460,000

tooling

1,334,400

80

166,030,000

Quality control


80

155750000

-

55953000


Total Flyaway Cost

2235900000

Unit Cost

6854200

Unit Price

7539600$

Figure 59 flyaway cost breakdown for UniBee 822

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15.4.2 Direct operating costs Low hourly operating cost is more important than unit price for business jet customers. As aircraft technologies be more updated, it becomes more efficient, which means hourly operating cost reduction. On the other hand, unit cost rises. So a balance between aircraft technologies and unit cost is needed. Aircraft operating cost includes expenses associated with flight, maintenance, depreciation expenditures, navigation, landing fees and registry taxes, which is explained below [22].

15.4.3 Flight direct operating costs 

Costs associated with flight includes of three categories, Fuel and oil, Crew and Airframe insurance

First for each category cost is calculated per nautical mile, finally considering aircraft operational life cycle, which assumes 10 years, and according to yearly business jets flight statistics, assumes 1000 flight hours yearly at least, and flight hourly operating cost is estimated. Fuel and oil It is calculated assuming the aircraft fuel (jet-1) with 6.66 lb. /gallon density the result illustrated in Table49 . Crew Assuming a business jet’s yearly pilot salary 150000 dollars and considering that there is no need for copilot presence in a five hour US coast-to-coast flight, costs are estimated in Table49 . Airframe insurance Business jet is been insured for reasons below: 

Possible damages to aircraft frame on ground or during flight



Probable dangers to the passengers



Probable dangers to third party



Probable damages to cargo

The airframe insurance calculations has been done and results are per nautical mile Table49 Table 49. Table49 costs associated with flight for UniBee

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DOC_flight element/nm

$/nm

Fuel & Oil

0.0054

Crew

0.4272

Insurance

0.0814

Total

0.5140

15.4.4 Maintenance Direct Operating Costs Maintenance costs are broken into costs for airframe, systems maintenance and engines maintenance Table50 : Table50 Maintenance Direct Operating Cost for UniBee DOC_maintenance element/nm

$/nm

Labor cost of airframe and systems

0.2842

Labor cost of engines

0.0899

Materials for airframe and systems

0.1814

Materials for engines

0.0804

Maintenance burden

0.4412

Total

1.138

Figure 60 DOC break down

Finally, UniBees hourly operating cost is nearly 2000 dollars, which in comparison with competing aircrafts is reasonable price. As seen in Figure 60 depreciation expenditures have formed 66% DOC ,

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Designing a Cost-Effective and high Efficient Business Jet so depreciation cost reduction causes less hourly operation costs(nearly 1000$/hour). Selecting suitable materials for airframe causes previously mentioned charges decrease as much as possible.

16 DeBiz Conclusion DeBiz firmly concluded UniBee, the fastest light business jet with longest range, will beat all the rivals in the market of light business jets and hold the future market with a great value of popularity. The greatest level of commonality between two types caused a lot in ease of manufacturing thus significant increase in the production rate capability happened. Canard configuration was the critical decision which made it possible to reach a better performance in category of light business jets which leaded us to even compete with medium business jets.

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17 References

[1] J. Roskam, "Airplane Design Part II: Preliminary Configuration Design and Integration of the Propulsion System," Roskam Aviation and Engineering Corporation, Ottawa, Kansas, 1985. [2] J. Roskam, Airplane Design Part III: Layout Design of Cockpit, Fuselage, Wing and Empennage: Cutaways andInboard Profiles, Kansas: Roskam Aviation and Engineering Corporation, 1986. [3] J. Roskam, Airplane Design Part 6, Kansas: Darcorp, 1985. [4] E. Torenbeek, Synthesis of Subsonic Airplane Design, Delft: Delft university press, 1982. [5] T. a. F. group, Aircraft Interior Comfort and Design, 2011. [6] L. M. Nicolai and G. E. Carichner, Fundamentals of Aircraft and Airship Design, Volume I Aircraft Design, American Institute of Aeronautics and Astronautics, Inc., 2010. [7] A.K.Kundu, Aircraft Design, 2010. [8] M. A. D. R. A.J.Kundu, Theory and Practice of Aircraft Perfomance. [9] Raymer, AIrcraft Design, 2004. [10] R. Kaubek, Aircraft Galley, Lavatory and Wator System, 2004. [11] D. Krane, The Real World of Businees Aviation: A Survey of Companies using General Aviation Aircraft, 2009. [12] J. Roskam, Airplane Design Part 1, kansas: darcorp, 1985. [13] L. M. Nicolai, Volume I Aircraft Design, Blacksburg: AIAA, 2012. [14] T. A. H. ,. A. S. P. A. David R.Downing, "Ride Quality Systems for Commuter Aircraft," INC. Flight research laboratory. Lawerence, 1983. [15] B. Etkin, Dynamics of Atmospheric Flight. [16] R. Pratt, Flight Control Systems, Practical Issues in Design and Implementation. [17] I. A. D. G. Duane McRuer, Aircraft Dynamics and Automatic Control. [18] D. McLean, Automatic Flight Control Systems. [19] o. H. Blakelock, Automatic Control of Aircraft. [20] W. H. Phillips, Study of a Control System to Alleviate Aircraft Response to Horizontal and Vertical Gusts NASA Technical note. [21] M. H. Sadraey, Aircraft Design a Systems Engineering Approach, New Hampshire, USA: John Wiley & Sons, Ltd., Publication, 2013. [22] J. Roskam, Airplane design part 8, 1990. [23] M. H. Sadrayi, Aircraft Design A System engineerings Approach, Kansas: Wiley, 2013. [24] J. Roskam, Airplane design part 3, Kansas: Darcorp, 1985. [25] J. Roskam and E. Lan, Airplane Aerodynamic and Performance, DAR coorporation, 1997. [26] T. A. H. A. S. P. A. David R. Downing, Ride Quality Systems for Commuter Aircraft, NASA Contractor, kansas, 1983. [27] a. Roskam, Airplane Flight Dynamics and automatic flight controls Part I.

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