21st century business jet

21st Century Business Jet Aircraft Design Group Project

The University of Adelaide

Department of Mechanical Engineering

Group One

Project Members

1. Santosh Ballal Amarnath (1187621)

2. Ngugen Thanh Tue (1184810)

3. Rui Tang (1188917)

Aircraft Design Project University of Adelaide

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Century Business Jets

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Table of Contents:

Table of contents…………………………………………………………………………..2

Abstract……………………………………………………………………………………5

List of figures……………………………………………………………………………...6

List of tables……………………………………………………………………………….6

Chapter 1 Introduction……………………………………………………………………..8

1.1 Scope of the project………………………………………………………………...8

1.2 Business jet – Yesterday and Today………………………………………………...8

1.3 Business jet definition and their market…………………………………………….9

1.4 Classification of business jet……………………………………………………….10

Chapter 2 External Research and Statistical Analysis…………………………………….12

2.1 Need for research…………………………………………………………………..12

2.2 Potential users and future design considerations for business jets………………...12

2.3 Market research, forecast and survey………………………………………………19

2.4 Defining project requirements…………………………………………………......26

2.4 .1 Design consideration for VLJ…………………………………………...…27

Chapter 3 Technical Task…………………………………………………………………...35

Chapter 4 First Sketch………………………………………………………………………37


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Chapter 5 Weight Estimation………………………………………………………………..38

5.1 Weights estimation…………………………………………………………………..38

5.2 Mission profile………………………………………………………………………38

5.3 First Calculation……………………………………………………………………..39

5.3.1 Fuel fraction calculations………………………………………...…………..39

5.3.2 Weights calculations…………………………………………………………..42

Chapter 6 Sensitivity Analysis……………………………………………………………...43

6.1 Takeoff weight sensitivity to payload weight……………………………………….43

6.2 Takeoff weight sensitivity to range………………………………………………….43

6.3 Takeoff weight sensitivity to endurance…………………………………………….44

6.4 Takeoff weight sensitivity to SFC (range case)…….……………………………….44

6.5 Takeoff weight sensitivity to SFC (endurance case).……………………………….44

6.6 Takeoff weight sensitivity to payload velocity..…………………………………….44

6.7 Takeoff weight sensitivity to L/D (range case).…………………………………….44

6.8 Takeoff weight sensitivity to L/D (endurance case)..……………………………….44

Chapter 7 Aircraft Sizing……………………………………………………………………45

7.1 Stall speed sizing……………………………………………………………………45

7.2 Takeoff distance sizing……………………………………………………………...45

7.3 Landing distance sizing……………………………………………………………..46

7.4 Drag Polar…………………………………………………………………………..46

7.5 Climb sizing………………………………………………………………………...47

7.6 Cruise speed sizing………………………………………………………………….48

7.7 Time to climb sizing………………………………………………………………...49

7.8 Sizing to ceiling………………………………………………………………….....50

7.9 Matching diagram…………………………………………………………………...50


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7.19 Comments on the matching diagram………………………………………………..51

Chapter 8 Overall Configuration Design…………………………………………………….52

8.1 Fuselage design………………………………………………………………………52

8.2 Wing design…………………………………………………………………………..55

8.3 Landing gear design………………………………………………………………….64

Chapter 9 Weight and Balance Analysis……………………………………………………..75

Chapter 10 Conclusion………………………………………………………………………78

Chapter 11 Final Drawings

References


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Abstract

From analyzing the business jet history to illustrating the future, this report shows a method

of designing the 21st century business jet. As broadly known, business jet is becoming more

and more popular all over the world. Therefore this report might be useful to the aircraft

engineers, designers, researchers and amateurs.

The first three chapters mainly concerned about the background research and market analysis

of business jet. However, after defining what sort of aircraft will be designed in this paper, the

project proceeds to a calculation stage. The chapters later on show the procedures of

calculations for a very light jet aircraft.


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List of tables

Table 2.2.1…………………………………………………………………………………12

Table 2.2.2…………………………………………………………………………………12

Table 2.2.3…………………………………………………………………………………14

Table 2.2.4…………………………………………………………………………………17

Table 2.3.1…………………………………………………………………………………19

Table 2.3.2…………………………………………………………………………………20

Table 2.3.3…………………………………………………………………………………21

Table 2.4.1…………………………………………………………………………………26

Table 2.4.2…………………………………………………………………………………30

Table 3.1……………………………………………………………………………………33

Table 3.2……………………………………………………………………………………34

Table 5.1.1…………………………………………………………………………………36

Table 7.4.1…………………………………………………………………………………43

Table 8.1.2…………………………………………………………………………………49

Table 8.2.1…………………………………………………………………………………51

Table 8.2.3…………………………………………………………………………………55

Table 8.2.4…………………………………………………………………………………56

Table 8.2.5…………………………………………………………………………………57

Table 8.2.6…………………………………………………………………………………58

Table 8.2.7…………………………………………………………………………………59

Table 8.3.1…………………………………………………………………………………66

Table 8.3.2…………………………………………………………………………………68

Table 9.1.1…………………………………………………………………………………69

Table 9.1.2…………………………………………………………………………………71


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List of figures

Figure 1.4.1…………………………………………………………………………………8

Figure 1.4.2…………………………………………………………………………………9

Figure 2.4.1…………………………………………………………………………………27

Figure 2.4.2…………………………………………………………………………………27

Figure 2.4.3…………………………………………………………………………………29

Figure 2.4.4…………………………………………………………………………………31

Figure 2.4.5…………………………………………………………………………………32

Figure 4.1...…………………………………………………………………………………35

Figure 5.1.2…………………………………………………………………………………36

Figure 7.9.1…………………………………………………………………………………47

Figure 8.1.1…………………………………………………………………………………62

Figure 8.1.2…………………………………………………………………………………62

Figure 8.1.3…………………………………………………………………………………63

Figure 8.1.4…………………………………………………………………………………63

Figure 8.1.5…………………………………………………………………………………64

Figure 8.1.6…………………………………………………………………………………65

Figure 8.1.7…………………………………………………………………………………66

Figure 8.1.8…………………………………………………………………………………68

Figure 9.1.1…………………………………………………………………………………71


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Chapter 1

1. Introduction

1.1Scope of the project in terms of Aircraft Design Process:

This project uses original/conceptual engineering design approach. The project mainly

covers the following areas of aircraft design:

• Preparation of technical task and writing mission specification based on

customer requirements, market survey, operational analysis and research.

• Aircraft conceptual design, preliminary design and detail design. Detail design

will be dealt partially and the other two (conceptual and preliminary design)

design stages will be the main focus of the project.

• Other aspects of aircraft design process are not in the scope of this project.

1.2 Business Jets – Yesterday & Today:

One of the most important technological innovations during the World War II was

introduction of jet planes. After the end of World War II many commercial airliners started to

realize the value of jet planes as they were faster than prop planes. As time progressed many

new concepts of jet planes came into picture and finally the concept of jet planes was made

feasible.

During 1962 to 1984 concept of globalization became very popular and there were many

high class business travelers, this was perhaps one of the reasons the airline companies had

introduced business class and first class. What business people wanted was not only to reach

the destination earlier but less hassle, less stress and less time in the airport. When jet travel

became a commercial enterprise, concept of having smaller jets for the business travelers

came into being. Finally when requirements of mega rich customers coupled with

requirement of business travelers were considered a new industry of business jets was born.


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Aviation industries like Lear, Lockheed, Bombardier and Gulfstream designed and

manufactured many such business jets. The interiors of these early business jets had

semblance of luxury hotels. Only after 1990’s business jet interiors started to have an

impression of offices and less like hotels. Jets now have LCD monitors, satellite phones, and

all the other equipment and accoutrements you would expect from a flying office. Jets are

now used not only for getting to the destination, but for getting things done on the way there.

The concept of using business jets was not limited for business travellers alone. It

became a very attractive proposition for government and federal bodies to use it for

transporting their VIPs and Head of state. These jets were also used for military operations

and express parcel deliveries. The market for business jets kept increasing and finally the

whole concept became commercially viable. However, not every business enterprise could

afford a business jet. Thus with time many air taxi and charter companies started to emerge

who bought business jets and provided on-demand and point to point air transportation.

Today Private jets are the ultimate way to travel to your business

destinations while working, resting, and travelling on a vacation or conferencing with

colleagues. If your business requires a lot of travel and you want to accomplish more while

traveling, then business jet is a good option. Whether you charter a jet as needed, own a

fractional jet share, or own a jet outright, you’ll enjoy being able to accomplish more in less

time with less stress.

1.3 Business jet definition and their market:

“Business jets are turbojet aircraft weighing less than 100,000 pounds maximum gross

takeoff weight, with wingspans less than 100 feet that are used by companies to conduct their

business” (GAO, August 2007).

Business jets are miniature aircrafts when compared to large passenger jet transport

aircrafts, primarily used by corporate bodies to transport their business executives,

government organizations to transport head of a country/state, VIPs and public bodies to


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transport their officials, Organizations providing Air taxis/charters for on demand passengers.

Business jets are also used by sporting bodies to transport the team members, press

corporations for express transportation of panel members and many bodies /individuals who

have a large associates and time is their crucial factor. However, these jets are also used for

pleasure or personal transportation and not for business purposes. For instance, celebrities use

it for their excursions and wealthy people use it for family trips etc…

A 21st century business jet is termed for an aircraft which can persuade over all

needs/desires of the above mentioned groups/bodies or individuals in a way faster or cheaper

or in way unique when compared with the older aircrafts of the same category. This project

aims at an endeavor to design such an aircraft.

1.4 Classification of Business Jets:

1.4.1 Business Jet Classification based on weight:

MTOW- Maximum Take Off Weight

Figure 1.4.1

Business Jets

Very Light Jets MTOW < 10000 lbs

Light Jets MTOW > 10000 lbs < 22500

lbs

Heavy Jets MTOW > 22500 lbs < 60000 lbs

Ultra Heavy Jets MTOW > 60000 lbs < 100000 lbs


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1.4.2 Business Jet Classification based on speed:

Figure 1.4.2

1.4.3 Business Jet Classification based on range:

Nm- Nautical Miles

Figure 1.4.3

Short Range Range < 1800nm

Business Jets

Medium Range Range > 1800nm < 4000nm

Long Range Range > 4000nm < 6500nm

Supersonic

Business Jets

Subsonic


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Chapter 2

2. External Research and Statistical Analysis

2.1 Need for Research

Now that we have defined business jet and also classified its types, it is a very important

for us to determine which of these types of business jets should be designed? In order to

answer this question we need to do gather information about the following:

Who are potential users in the future?

What are the main issues or problems involving business jet industries? How to

overcome them?

What forecasters are saying?

What kind of technological innovations or growth the business jet industries are

expecting?

How to offer a unique and competitive service to existing scheduled operations?

What could be the alternative roles of business jet aircrafts?

2.2 Potential users and future design considerations for business jets:

Primary users of business jets are business men from many multi-national companies and

corporate bodies whose business required a lot of travel. However, with the advent of global

delivery models, fast internet bandwidth and many other available services like video and

voice conferencing the frequency of travel of such business men has reduced with time. Due

to this reason it is not necessary for the entire business panel or team to travel to the client’s

location, only required members whose work cannot be accomplished with the use of above

mentioned services need to travel. Thus the number of people travelling is reducing with

time.


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This factor should be considered in future when a business jet is designed for such business

travellers.

Government and federal organizations continue to be potential users of business jet.

However, in terms of government used business jet, some of the information should be

concerned when it is being designed. First of all, a critical question should be raised: how

many people will there be in a government group? Researching on the internet, a number of 4

to 10 members is the typical group size. That is, in government groups only certain classified

levels of person are eligible to have such a facility. There are other aspects like safety level,

cost and maintenance of aircraft that should be considered before designing for government

and federal bodies.

Air taxi and charter companies find it very difficult to always operate at full loads.

Usually there are many delays and cancellation of flights due to lack of availability of

minimum number of passengers and hence keeping a fixed cost per passenger seat becomes

very difficult. More delays or more cancellation means more maintenance cost to keep the

airplane stationary in an airport. There is a heavy price that these companies have to pay for

such reasons. Hence while designing a business jets for such bodies, one has to keep in mind

the number of passengers and the most frequently used destinations and distance of travel and

maintenance cost of aircraft in an airport.

Also with the increasing number of wealthy people in the world and increasing

technologies in the field of material and avionics, if one would design a lighter and cheaper

business jet, then there is a potential market of selling the jets for such people and they could

use it for personal or pleasure purposes rather than business purpose. Such a trend has already

started and there has been few design concepts emerging in the aviation industry.

It is important for us to know who among the above mentioned groups fly more when

compared with other groups. The below mentioned charts gives us an explanation and also

shows the future trend of flying.


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Table 2.2.1

Use Percentage

of flying

hours

Description

Air Taxi 10.6 On demand passengers and all cargo operations

Business 12.0 Use of aircraft in connection with pilot’s occupation or private business

Corporate 11.4 Use of aircraft owned or leased by a corporation or business and flown

by professional pilot

Instructional 13.5 Flying under the supervision of a flight instructor

Personal 34.3 Use of aircraft for pleasure or personal transportation and not for

business purpose

Other uses 17.9 Examples Include: Federal State, or local government owned or leased

aircraft used for a government function

Total 100 The total was rounded off to 100

Source: FAA

It is evident from Table 2.2.1 that majority of flying hours are contributed by personal

uses.

Now we have to consider the distances the business jet has to be designed for such

customers. Generally speaking, two different ranges should be considered, that is both

domestic and international. For one hand, if domestic air routes are considered, the ranges

between the main cities in Australia can be found as follows:

Table 2.2.2

Adelaide Brisbane Canberra Hobart Melbourne Perth Sydney

Adelaide N/A 1599 968 1164 655 2138 1165

Brisbane 1599 N/A 935 1786 1370 3614 728

Canberra 968 935 N/A 863 473 3106 240

Hobart 1164 1786 863 N/A 601 3020 1058

Melbourne 655 1370 473 601 N/A 2730 713

Perth 2138 3614 3106 3020 2730 N/A 3301

Sydney 1165 728 240 1058 713 3301 N/A

Note: the values are all in kilometers in this table.

As can be seen from the table above, if considering the domestic bookings, the

longest distance should be applied to when designing the business jet, which is 3614 km and

can be rounded up to 3700 km. Also the average distance could be calculated which is around

2300 kms.


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On the other hand, if the design must be used in a global range, the main cities distance

are tabulated as follows:

Table 2.2.3

Cities Berlin Buenos

Aires

Cairo Calcutta Cape

Town

Caracas Chicago

Berlin — 7,402 1,795 4,368 5,981 5,247 4,405

Buenos Aires 7,402 — 7,345 10,265 4,269 3,168 5,598

Cairo 1,795 7,345 — 3,539 4,500 6,338 6,129

Calcutta 4,368 10,265 3,539 — 6,024 9,605 7,980

Cape Town 5,981 4,269 4,500 6,024 — 6,365 8,494

Caracas 5,247 3,168 6,338 9,605 6,365 — 2,501

Chicago 4,405 5,598 6,129 7,980 8,494 2,501 —

Hong Kong 5,440 11,472 5,061 1,648 7,375 10,167 7,793

Honolulu 7,309 7,561 8,838 7,047 11,534 6,013 4,250

Istanbul 1,078 7,611 768 3,638 5,154 6,048 5,477

Lisbon 1,436 5,956 2,363 5,638 5,325 4,041 3,990

London 579 6,916 2,181 4,947 6,012 4,660 3,950

Los Angeles 5,724 6,170 7,520 8,090 9,992 3,632 1,745

Manila 6,132 11,051 5,704 2,203 7,486 10,620 8,143

Mexico City 6,047 4,592 7,688 9,492 8,517 2,232 1,691

Montreal 3,729 5,615 5,414 7,607 7,931 2,449 744

Moscow 1,004 8,376 1,803 3,321 6,300 6,173 4,974

New York 3,965 5,297 5,602 7,918 7,764 2,132 713

Paris 545 6,870 1,995 4,883 5,807 4,736 4,134

Riode Janeiro 6,220 1,200 6,146 9,377 3,773 2,810 5,296

Rome 734 6,929 1,320 4,482 5,249 5,196 4,808

San Francisco 5,661 6,467 7,364 7,814 10,247 3,904 1,858

Shanghai 5,218 12,201 5,183 2,117 8,061 9,501 7,061

Stockholm 504 7,808 2,111 4,195 6,444 5,420 4,278

Sydney 10,006 7,330 8,952 5,685 6,843 9,513 9,272

Tokyo 5,540 11,408 5,935 3,194 9,156 8,799 6,299

Warsaw 320 7,662 1,630 4,048 5,958 5,517 4,667

Washington,

D.C.

4,169 5,218 5,800 8,084 7,901 2,059 597


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Table 2.2.3 (continued)

Cities

Hong

Kong

Honolul

u Istanbul Lisbon London

Los

Angeles Manila

Berlin 5,440 7,309 1,078 1,436 579 5,724 6,132

Buenos Aires 11,472 7,561 7,611 5,956 6,916 6,170 11,051

Cairo 5,061 8,838 768 2,363 2,181 7,520 5,704

Calcutta 1,648 7,047 3,638 5,638 4,947 8,090 2,203

Cape Town 7,375 11,534 5,154 5,325 6,012 9,992 7,486

Caracas 10,167 6,013 6,048 4,041 4,660 3,632 10,620

Chicago 7,793 4,250 5,477 3,990 3,950 1,745 8,143

Hong Kong — 5,549 4,984 6,853 5,982 7,195 693

Honolulu 5,549 — 8,109 7,820 7,228 2,574 5,299

Istanbul 4,984 8,109 — 2,012 1,552 6,783 5,664

Lisbon 6,853 7,820 2,012 — 985 5,621 7,546

London 5,982 7,228 1,552 985 — 5,382 6,672

Los Angeles 7,195 2,574 6,783 5,621 5,382 — 7,261

Manila 693 5,299 5,664 7,546 6,672 7,261 —

Mexico City 8,782 3,779 7,110 5,390 5,550 1,589 8,835

Montreal 7,729 4,910 4,789 3,246 3,282 2,427 8,186

Moscow 4,439 7,037 1,091 2,427 1,555 6,003 5,131

New York 8,054 4,964 4,975 3,364 3,458 2,451 8,498

Paris 5,985 7,438 1,400 904 213 5,588 6,677

Riode Janeiro 11,021 8,285 6,389 4,796 5,766 6,331 11,259

Rome 5,768 8,022 843 1,161 887 6,732 6,457

San Francisco 6,897 2,393 6,703 5,666 5,357 347 6,967

Shanghai 764 4,941 4,962 6,654 5,715 6,438 1,150

Stockholm 5,113 6,862 1,348 1,856 890 5,454 5,797

Sydney 4,584 4,943 9,294 11,302 10,564 7,530 3,944

Tokyo 1,794 3,853 5,560 6,915 5,940 5,433 1,866

Warsaw 5,144 7,355 863 1,715 899 5,922 5,837

Washington,

D.C. 8,147 4,519 5,215 3,562 3,663 2,300 8,562


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Table 2.2.3(continued)

Cities

Mexico

City

Montre

al Moscow

New

York Paris

Rio de

Janeiro Rome

Berlin 6,047 3,729 1,004 3,965 545 6,220 734

Buenos Aires 4,592 5,615 8,376 5,297 6,870 1,200 6,929

Cairo 7,688 5,414 1,803 5,602 1,995 6,146 1,320

Calcutta 9,492 7,607 3,321 7,918 4,883 9,377 4,482

Cape Town 8,517 7,931 6,300 7,764 5,807 3,773 5,249

Caracas 2,232 2,449 6,173 2,132 4,736 2,810 5,196

Chicago 1,691 744 4,974 713 4,134 5,296 4,808

Hong Kong 8,782 7,729 4,439 8,054 5,985 11,021 5,768

Honolulu 3,779 4,910 7,037 4,964 7,438 8,285 8,022

Istanbul 7,110 4,789 1,091 4,975 1,400 6,389 843

Lisbon 5,390 3,246 2,427 3,364 904 4,796 1,161

London 5,550 3,282 1,555 3,458 213 5,766 887

Los Angeles 1,589 2,427 6,003 2,451 5,588 6,331 6,732

Manila 8,835 8,186 5,131 8,498 6,677 11,259 6,457

Mexico City — 2,318 6,663 2,094 5,716 4,771 6,366

Montreal 2,318 — 4,386 320 3,422 5,097 4,080

Moscow 6,663 4,386 — 4,665 1,544 7,175 1,474

New York 2,094 320 4,665 — 3,624 4,817 4,281

Paris 5,716 3,422 1,544 3,624 — 5,699 697

Riode Janeiro 4,771 5,097 7,175 4,817 5,699 — 5,684

Rome 6,366 4,080 1,474 4,281 697 5,684 —

San Francisco 1,887 2,539 5,871 2,571 5,558 6,621 6,240

Shanghai 8,022 7,053 4,235 7,371 5,754 11,336 5,677

Stockholm 5,959 3,667 762 3,924 958 6,651 1,234

Sydney 8,052 9,954 9,012 9,933 10,544 8,306 10,136

Tokyo 7,021 6,383 4,647 6,740 6,034 11,533 6,135

Warsaw 6,365 4,009 715 4,344 849 6,467 817

Washington,

D.C. 1,887 488 4,858 205 3,829 4,796 4,434


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Table 2.2.3(continued)

Cities

San-Fra

ncisco

Shangha

i

Stockho

lm Sydney Tokyo Warsaw

Washing

ton

Berlin 5,661 5,218 504 10,006 5,540 320 4,169

Buenos Aires 6,467 12,201 7,808 7,330 11,408 7,662 5,218

Cairo 7,364 5,183 2,111 8,952 5,935 1,630 5,800

Calcutta 7,814 2,117 4,195 5,685 3,194 4,048 8,084

Cape Town 10,247 8,061 6,444 6,843 9,156 5,958 7,901

Caracas 3,904 9,501 5,420 9,513 8,799 5,517 2,059

Chicago 1,858 7,061 4,278 9,272 6,299 4,667 597

Hong Kong 6,897 764 5,113 4,584 1,794 5,144 8,147

Honolulu 2,393 4,941 6,862 4,943 3,853 7,355 4,519

Istanbul 6,703 4,962 1,348 9,294 5,560 863 5,215

Lisbon 5,666 6,654 1,856 11,302 6,915 1,715 3,562

London 5,357 5,715 890 10,564 5,940 899 3,663

Los Angeles 347 6,438 5,454 7,530 5,433 5,922 2,300

Manila 6,967 1,150 5,797 3,944 1,866 5,837 8,562

Mexico City 1,887 8,022 5,959 8,052 7,021 6,365 1,887

Montreal 2,539 7,053 3,667 9,954 6,383 4,009 488

Moscow 5,871 4,235 762 9,012 4,647 715 4,858

New York 2,571 7,371 3,924 9,933 6,740 4,344 205

Paris 5,558 5,754 958 10,544 6,034 849 3,829

Riode Janeiro 6,621 11,336 6,651 8,306 11,533 6,467 4,796

Rome 6,240 5,677 1,234 10,136 6,135 817 4,434

San Francisco — 6,140 5,361 7,416 5,135 5,841 2,442

Shanghai 6,140 — 4,825 4,899 1,097 4,951 7,448

Stockholm 5,361 4,825 — 9,696 5,051 501 4,123

Sydney 7,416 4,899 9,696 — 4,866 9,696 9,758

Tokyo 5,135 1,097 5,051 4,866 — 5,249 6,772

Warsaw 5,841 4,951 501 9,696 5,249 — 4,457

Washington,

D.C. 2,442 7,448 4,123 9,758 6,772 4,457 —

Note: the values are in miles in this table.


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As can be seen from the tables above, the longest distance has to be considered in the

global ranges is 11,533 miles, which can be converted to 18,560 km. Therefore, if the product

has to cover the global services, a range of 18,560 km should be considered. The average of

the distances is around 5300 miles, approx 8500 km.

Finally, how fast do they want to travel? Although there are seldom statistics on the

flying time requirements of the different groups, the mainly consideration in this case is the

normal flying durations which are currently operated by the commercial airliners.

Table 2.2.4 Adelaide Brisbane Canberra Hobart Melbourne Perth Sydney

Adelaide N/A 2:00 1:15 1:30 0:50 2:45 1:30

Brisbane 2:00 N/A 1:15 2:20 1:45 4:30 0:55

Canberra 1:15 1:15 N/A 1:05 0:40 3:55 0:20

Hobart 1:30 2:20 1:05 N/A 0:45 3:50 1:20

Melbourne 0:50 1:45 0:40 0:45 N/A 3:25 0:55

Perth 2:45 4:30 3:35 3:50 3:25 N/A 4:10

Sydney 1:30 0:55 0:20 1:20 0:55 4:10 N/A

Note: for 1:15 means 1 hour and 15 minutes.

Therefore, using the typical flying durations which the most airliners operate as the table

showed above, the probable speed of this business jet can be calculated using the values in

table 2.2.2 divided by the values in table 2.2.4 and, finally the results is around 850 km/h.

2.3 Market Research, Forecast and Survey:

Most of the market forecasters and analysts from reputed aeronautical industries

forecasted that aviation business will grow over next 20 years with annual growth rate of

3.5% to 5 %. However, because of the current economic crisis the growth is expected to slow

down. Forecast organizations & Aviation industries like Embraer, Honeywell, PMI Media,

Forecast International, Teal Group and FAA still feel that despite the economic crisis there


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will be a continuous growth in air transport demand and growth will be 1% in 2009 and 4.9%

for a period of 2009 to 2028. (Embraer-Mkt-Outlook-2009-2028,2009).

Despite the fact that this is good for all the aviation allied industries for their growth in

business with increase in demand for air transport, it also means that necessary expansion and

developments in airports and related infrastructure is necessary to meet these demands. Many

international airports in the world are already experiencing the peak load and have been

operational beyond its saturation point. Projects related to such expansions are not in control

of aviation industries and are usually influenced by economical, environmental, social and

political factors. In the past these factors have delayed many proposed developments and

expansions of airports and related infrastructure. There is no indication of improvements

under such circumstances in the near future.

Demands for amenities in existing main airports are ever increasing, with this increase in

demand there will be many delays and this can be a potential threat in the future.

Investigations in main airports has shown that 30% of aircraft movements involve very big or

large airplanes, the rest of movements are because of the relatively smaller planes. These

small aircrafts do not need all the amenities that are available in main airports. Thus

separating these categories of planes will help improve the efficiency of the main airports.

Many researchers have recommended that shifting the smaller planes to smaller airports like

regional or satellite airports and connecting satellite airports with the main airports through

ground travel will help improve the current situation. This will also improve the efficiency of

the main airport and will not require many changes to accommodate the future demand.

The smaller planes mentioned above includes all the varieties of business jets. Let us

have a look on which type of business jet has a potential market and why? What are the

forecasters saying?


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The following table gives us the forecast (2007-2016) by Embraer of business jets by product

segment.

Table 2.3.1

Segment Total

Deliveries

Share

Very Light 2,715 24%

Light 2,390 21%

Mid-Light 1,080 10%

Mid-Size 1,305 12%

Super

Mid-Size 1,250 11%

Large 1,310 12%

Ultra-Long

Range 850 8%

Ultra-Large 215 2%

Total

(2007-2016) 11,115 100%

Source: EMBRAER FORECASTE, 2007

Embraer had estimated an overall demand for 11,115 business jets over the next eight

years, the values of the sales is expected to be approximately US$ 169 billion. It has also

been estimated that the new air taxi market may add another 2,500 to 3,000 aircraft to the

Very Light Jet (VLJ) segment.

From the forecast, it is evident that Very Light Jets have the major market share. Also the

light jets have a good share in the market which is just 3% lesser when compared with very

light jets. The other categories of business jets have a huge difference in the margins.


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Let us have a look at what forecast organizations have predicted on total number of very

light jets deliveries.

Table 2.3.2

Source: GAO analysis of very light jet forecasts.


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Let us have a look on what are the assumptions made by these forecast organizations in

making very light jet forecasts.

Table 2.3.3

Source: GAO analysis of very light jet forecasts


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Definition of Very Light Jets:

“ very light jets are jet aircraft with a maximum take-off weight of 10,000 pounds,

certificated for single pilot operations, equipped with advanced avionic systems, and priced

below other business jets.” (GAO, August 2007).

FAA and the aviation industries consider very light jets to be general aviation aircraft because

of the way they will operate in the NAS (National Airspace Systems)

Definition in terms of Maximum Take Off weight (MTOW), Range, Cruise Speed, Cabin

Volume per Passenger, price: Table 2.3.4

Source: Manufacturer websites, Conklin & de Decker, SH&E Research

0

5,000

10,000

15,000

20,000

25,000

30,000

Twin Piston

Single Turbo

Twin Turbo Low VLJ High VLJ Light Jet

MT

OW

(lb

s)

Min

0

500

1,000

1,500

2,000

2,500

3,000

Twin PistonSingle TurboTwin Turbo Low VLJ High VLJ Light Jet

Nau

tica

l Mile

s

Min


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Source: Manufacturer websites, Conklin & de Decker, SH&E Research

0

20

40

60

80

100

120

Twin Piston Single Turbo

Twin Turbo Low VLJ High VLJ Light Jet

Ca

bin

Vo

lum

e (

ft3

) p

er

Pa

sse

ng

er

Min

0

100

200

300

400

500

600

Twin PistonSingle TurboTwin Turbo Low VLJ High VLJ Light Jet

Max

imu

m C

ruis

e S

pee

d,

KT

AS

Min

$0

$5

$10

$15

$20

$25

0.0 0.5 1.0 1.5 2.0 2.5

VLJs

Twin Pistons

Single Turbos

Twin Turbos

Light Jets

Medium Jets

Super Mid Jets

Price in

Millions

(USD)

Performance index- Index less

useful for each purchase decision


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2.4 Defining Project Requirements:

From the discussion from section 2.2 and section 2.3 we can summarize the following:

o The numbers of passengers travelling on business purposes are reducing.

o The government bodies continue to use business jets, but passengers travelling

are limited and operating and maintaining cost should be less, safety level

should be more.

o Air taxi and charter companies are finding it difficult to operate with full loads

thus the number of passengers requirement could be reduced also cost of

keeping the aircraft in the airport should be less

o Wealthy people are using business jets for their pleasure or personal purposes.

This fact is also evident from table 2.2.1

o The average distance from table 2.2.2 for domestic travel is 2300kms.

o The average distance from table 2.2.3 for international travel is 8500kms.

o The average speed from table 2.2.4 for air travel is about 805km/hr.

o The main airports are getting congested with 70% smaller aircrafts operating in

main hubs.

o Moving these smaller aircraft to satellite airports is considered to be a good

option

o Market share of light jets and very light jets are higher compared with market

shares of other categories of business jets.

o VLJ have MTOW of 1000lbs, can have a range of about 2000nm, 400-500 knots

and they are priced below 5 million USD.

Analysing the summary we can conclude that designing very light jet with a little trade

off in range of travel we can get a good market share and we can target majority of

customer groups.


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2.4.1 Design Considerations for VLJ:

This part we will analyse and consider, in detail, each of the design parameters required to

design a VLJ.

(1) Certification

The certification requirement should be FAR 23, as FAA considers VLJ will operate similar

to General Aviation (GA) aircrafts and maximum takeoff weight of VLJ is less than

19000lbs.

(2) Capacity and Payload

The optimal payload for a VLJ will be 4-8 passengers so that the Take Off weight is within

the range and also because of the reasons mentioned in the survey. Mean value of 6

passengers should be reasonable.

The aircraft should be designed to fly with a single pilot and this is from the definition of

VLJ.

Baggage allowance is a standard value could be any value between 30-40lbs per passenger.

In order to limit the value of maximum takeoff weight we will consider 30 lbs per passenger.

(3) Range

Range selection is very crucial parameter, from our survey we know that average domestic

range is around 1300nm (2300km) and average international range is around 4600nm

(8500km). From the definition of VLJ (table 2.3.4) for VLJ maximum range is around

2000nm. Hence a range of 2000nm is very reasonable. Also from definition of VLJ, advance

avionic systems are present, hence this range is IFR range.


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(4) Cruise Speed

The speed at which the aircraft should fly is a very important factor and from our survey the

value is around 805km/hr. However, from definition of VLJ (table 2.3.4) the cruise velocity

is around 500 knots (926km/hr), we can round this off to 0.8 mach for cruise phase.

(5) Power Plant

Type of power plant depends on the mach number of the plane, for a value of 0.8 mach a high

bypass ratio turbofan is a good choice. Searching the available engines in the current market,

the suitable models were found as follows:

Table 2.4.1 Engine List

Model

Manufac

turer

NO. Of Turbine

Length (inches)

Diameter (inches)

Dry weight (lbs)

SFC (lbs/lbs/h

rs)

Thrust (lbf)

CJ610 GE 2 45.4-51.5 17.7 396-421 0.96-0.97 (MAX)

2850-3100

(MAX) PW615

F Pratt & Whitney

2 49.5 16 310 N/A 1350 (Take off)

FJ33 Williams 2 47.9 17.3 300 0.486 (SLS)

1200 (Static)

HF120 GE Honda

2 44 21.2 400 0.7

2050 (Take off)

Referring to the calculations shown in “chapter 5 weight calculation”, the Williams FJ33 was

selected. However this model is a trade off between costs and power and the market shares. If

a more popular engine is used, the maintenance will not cost the owner too much.

However the dimension of Williams FJ33 is shown as follows:


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Figure 2.4.1 Engine Williams FJ33 Dimension

Source: http://www.williams-int.com/information.html?pid=6

Figure 2.4.2 Engine Williams FJ33 Profile

(6) Altitude

The altitude at which this flight should fly is determined by capabilities of structure, engine

and characteristics of equipment. Usually for FAR23 planes altitude should not be more than

25000ft, and the cabins should be pressurized unless and until the luminous transmittance

value is more than 70%. These particular constraints are for VFR operations. However, we

are considering IFR operations and because of the type of engine and statistics it can be

shown that a value of 41000ft is a reasonable altitude.


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(7) Range of Alternative Airport

Flying to alternate airport during emergency conditions is very much desired and the range

for alternate airport flying is around 100nm. The reason being, there is a regional/satellite

airport within the radius of 50 to 70nm from all international airports or main airports. Hence

100nm should be a safe value.

(8) Loiter Endurance

Time is a crucial factor for passengers using VLJ and we assumed that small aircrafts will be

deviated to smaller airports to reduce traffic in main hubs. Hence less congestion is expected

and loitering is undesirable in such situations. However, considering that VLJ is used to

land in a main airport a loitering time of 15mins is safer.

(9) Takeoff and Landing Distance

Takeoff and Landing distances should be minimized as much as possible, as VLJ will be used

to land or takeoff from a regional or satellite airport which will have shorter run ways when

compared with main/international airports. From statistics a value of 750m (2460ft) for

takeoff distance and a value of 680m (2230ft) for landing distance.

(10) Aspect Ratio

Aspect ratio of 7.5 – 8 is estimated from statistical data for similar category of planes and,

however is estimated from the first sketch as well.

(11) Swet/Sref

Swet/Sref of 8 is estimated from statistical data for similar category of planes.

(12) L/D

L/Dmax value of 15 is estimated from the diagram as follows.


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Figure 2.4.3 L/D

As maximum value is 15, the value of cruise could be 13 and value for alternate airport flying

could be 12. The maximum value could be used for loiter phase.

In order to produce enough lift a double slotted flap is used along with wing lets. Value of CL,

CLmax, and CLL depends on this data.

(13) Wing Type

Overall configuration should be selected with low wing and engines on rear near the tail. The

low wing configuration will help in improvement of crashworthiness of the aircraft and


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produces good lift. Engines cannot be mounted on wings because of minimum clearance

between engine nacelle and ground.

(14) Landing Gear Type

Landing gears should be retractable type, in order to increase lift and reduce drag. However

the distance between two main gears must meet the angle criteria. The whole design is shown

in the later chapters.

(15) Regression Coefficients

The regression coefficient A and B which are used in the calculation can be calculated based

on the prototypes. In this paper, 14 prototypes of different models and manufactures were

selected.

Table2.4.2 Regression Coefficient Calculations

Model of the aircraft WTO We logWTO logWe

Falcon 10 18740 10760 4.27277 4.031812

Cessna Citation I 11850 6605 4.073718 3.819873

Cessna Citation II 13300 7196 4.123852 3.857091

LearJet 24 13500 7064 4.130334 3.849051

LearJet 25 15000 7650 4.176091 3.883661

Piaggio PD-808 18000 10650 4.255273 4.02735

Cessna citation CJ-1 10700 6765 4.029384 3.830268

Eclipse 500 5950 3550 3.774517 3.550228

Phenom 100 10472 7132 4.02003 3.853211

Beachcraft premium 12500 8430 4.09691 3.925828

Cessna citation mustang 8645 5550 3.936765 3.744293

Adam a700 9350 5550 3.970812 3.744293

Honda HA 420 9200 5480 3.963788 3.738781

Diamond jet D-jet 6562 3855 3.817036 3.586024


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From the table above, the relationship between the weights can be plotted as follows:

4000 6000 8000 10000 12000 14000160001800020000

4000

6000

8000

10000

Em

pty

Wei

ght ~

We

~ lb

s

Take off Weight ~ Wto ~ lbs

Figure 2.4.4 Weight Diagram of Prototypes

However, if we plot the values in the last two columns, the regression coefficients can be

found:


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3.5 3.6 3.7 3.8 3.9 4.0 4.13.7

3.8

3.9

4.0

4.1

4.2

4.3

lo

gW(T

O)

logW(e)

Figure 2.4.5 Regression Coefficient Linear Fit

Therefore the coefficient is:

A = 0.15549

B = 1.01914

Referring to the values for business jet in Roskam’s textbook,

A = 0.2678

B = 0.9979

The results are reasonable enough for the VLJ (very light jet).


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Chapter 3 3. Technical Task By combining all the design above, the technical task can be tabulated, however we break

down the TT into two categories, and one is the structure and configuration of the aircraft

while the other is the performance and attributes of the aircraft.

Table 3.2 List of performance

Parameters Specifications

Certification FAR 23

Cruise speed 0.80 mach

Cruise height 41000 ft

Cruise height (alternative) 24600 ft

Range 2000 nm

Climb rate 477.24 ft/sec

Descent rate 477.24 ft/sec

Loitering time 15 min

Type of engine High bypass turbofan

Name of engine Williams FJ33

Number of engine 2

Length 47.9 inches

Diameter 19.03 inches

Dry weight 310 lbs

Thrust 1800 lbs

SFC 0.486 lbs/lbs/hr

Fly to alternate airport 100 nm

Ccr 0.5 lbs/lbs/hrs

Cloiter 0.4 lbs/lbs/hrs

(L/D)cr 13

(L/D) loiter 15


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Regression coefficient A,B A=0.15549; B=1.01914

Takeoff distance 750 m

Landing distance 650 m

CLclean 1.8

CLTO 2.1

CLL 2.5

WL/WTO 0.85

Aspect Ratio (AR) 7.5

Swet/Sref 8

e 0.75~0.8

Wing Configuration Low wing configuration

Standard FAR 23

Engine location Rear

Type of landing gear Retractable

Wing airfoil NACA 4412

Empennage airfoil NACA 0009

Flaps Fowler double slots

Tail T-tail


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Chapter 4 4. First Sketches: The first sketch shows the concepts of the design. However it is based on the prototypes,

empirical statistics and technical tasks as narrated above.

Figure 4.1 First Sketch

Aircraft Initial Sketch with low wing configuration , engines mounted on rear and

retractable landing gears


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Chapter 5 5. Weight Estimation:

5.1 Prototypes

Before designing our business jet, it is necessary to find some prototypes by researching the

current products in the market. However, some typical models are listed as follows:

Table 5.1.1 Prototypes for Weight Estimation

Model Capacity WTO We Range

Cessna Mustang 4~5 8645 lbs 5550 lbs 1167 nm

Adam A-700 4~6 9350 lbs 5550 lbs 1611 nm

Diamond D-jet 3~4 6562 lbs 3855 lbs 1350 nm

5.2 Mission Profile

The typical mission profile for this business jet can be illustrated as follows:

Figure 5.1.2 Mission Profile

Climb

Start, Taxi, Takeoff

Cruise Loiter

Alternate

Descent

Landing, taxi, shut down


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5.3 First Calculations

5.3.1 Fuel Fraction Calculations

Phase 1: Engine start, warm up

Phase 2: Taxi

Phase 3: Take off

Phase 4: Climb

Phase 5: Cruise

The cruise range can be calculated as follows:

And the climb and descent range are determined by:

Here we assume the velocity of takeoff and landing is 180 ft/sec and, however the climbing time and descending time is 20 min and 10 min relatively. Therefore:

As the values assumed in the mission profile:

, ,

Therefore:


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Phase 6: Loiter

As assumed above, the endurance of loiter phase is 15 min = 900 sec. and the values are therefore:

,

Phase 7: Reserved cruise

As the definition above, the values are:

, , , And therefore:

Phase 8: Descent

Phase 9: Landing, Taxi and Shut down

Finally the fuel fraction can be calculated as follows:


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5.3.2 Weights Calculations

Therefore, the equation can be found as:

(1)

And apply the Roskam’s equation by using the regression coefficient A and B as calculated in the previous pages.

(2)

Solving the equation (1) and (2), the takeoff weight, empty weight and fuel weight of the business jet can be found as:

5.3.3 Trade study of the payload and range

The diagrams can be found as


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Chapter 6 6. Sensitivity Analysis

6.1 Takeoff weight sensitivity to payload weight

Applying the equation below, the takeoff weight sensitivity to payload weight can be

calculated as:

Where the coefficient A and B are the regression coefficient and where C and D can be

calculated as:

Therefore the sensitivity is:

6.2 Takeoff weight sensitivity to range

Applying the equation below, it is calculated as:

6.3 Takeoff weight sensitivity to endurance



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6.4 Takeoff weight sensitivity to SFC (range case)


6.5 Takeoff weight sensitivity to SFC (endurance case)


6.6 Takeoff weight sensitivity to velocity


6.7 Takeoff weight sensitivity to L/D (range case)


6.8 Takeoff weight sensitivity to L/D (endurance case)



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As can be seen from the calculations, the SFC is the most effects to the takeoff weight.

Therefore, a good engine model must be selected in order to decrease the SFC.

Chapter 7 7. Aircraft sizing

7.1 Stall speed sizing

According to FAR 23, those aircrafts should be sized for the stall speed if the takeoff weight

is smaller than 12500 lbs. As can be seen from “Chapter 5, First calculation”, the takeoff

weight is 8625 lbs, hence the stall speed sizing is necessary and it has to be smaller than 61

knots.

As mentioned in the technical task in “Chapter 4, Technical Tasks”, the lift coefficient is:

Therefore,

7.2 Takeoff distance sizing

By the requirements of sizing the takeoff distance in FAR 23, first of all, assuming the VTO is

at about 1.1 Vs, and the following equation can be used:

Secondly, the TOP23 can be found as:

Where the STOG can be found as:


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Assuming the takeoff altitude is 500 m, and the air density ratio is:

Therefore:

7.3 Landing distance sizing

Using the requirement given in the FAR 23 and as assume above, the parameters are:

Therefore:

7.4 Drag Polar

As designed above, the values are:

The drag polar can be found as:

Table 7.4.1 Drag Polar

Configuration CD0 e CD CLmax

Clean

0.036 0.8 0.036+CL2/18.84 1.65

Takeoff flaps

Gear up

0.054 0.75 0.054+CL2/17.66 2.1


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Takeoff flaps

Gear down

0.066 0.75 0.066+CL2/17.66 2.1

Landing flaps

Gear up

0.096 0.7 0.096+CL2/15.4 2.5

Landing flaps

Gear down

0.116 0.7 0.116+CL2/15.4 2.5

7.5 Climb Sizing

(1) FAR 23.65 (AEO), CGR=0.04

For jet engines aircraft the following equation should be applied:

Where the L/D can be calculated step by step as follows:

Therefore:

Hence:

Finally,

(2) FAR 23.67 (OEI), CGR=0.012



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Therefore:

Hence:

Finally,

However, if the temperature is 81F, at 5000 ft height, CGR=0.006:

(3) FAR 23.77 (AEO), CGR=0



Therefore:

Hence:

Finally,


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7.6 Cruise Speed Sizing


Where the values are given as follows:

Therefore:

7.7 Time to Climb Sizing

The time of climbing is defined to 20 minutes. For jet engines aircraft, the equation below

should be applied:

For business jet, the habs=45000 ft, therefore:

However the rate of climb should be calculated as:


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Where L/D = 15, hence,

However

Therefore:

7.8 Sizing to Ceiling

According to the FAR 23, the minimum required climb rate is RC=500 fpm.

Therefore, the T/W can be calculated as follows:

7.9 Matching Diagram

Plugging in all the values obtained above, the matching diagram can be plotted as:


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Figure 7.9.1 Matching Diagram

7.10 Comments on the matching diagram

As can be seen from the matching diagram, the MET POINT can be found. If we the stall

speed is increased, then the VLJ will have a bigger value of W/S at the same required thrust.

However if ceiling is reduced, then the VLJ needs smaller value of T/W. This means that the

more economical the VLJ is. From the design point we can compute the required thrust and

the wing area of the VLJ.

(1) For wing span

(2) For engine thrust

Therefore, each engine has to generate more than 1643.5 lbs.


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Chapter 8 8. Overall Configuration Design

8.1 Fuselage Design

8.1.1 Crew Cabin Design

Very Light Jets should be certified for single pilot operations. However, customers request for

2 pilots, just to get peace of mind and safe flying. In terms of certification this jet needs to be

certified for single pilot, but in terms of design, we will consider 2 pilots in place. Therefore,

whenever there are 2 pilots, number of passengers reduces to 5 and when single pilot is

considered, passenger capacity will be 6.

For this project we have used recommended dimensions of the cockpit for small aircrafts with


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stick control from the book, ‘Synthesis of subsonic airplane’, by E.Torenbeek.

For the final output of our design, refer chapter 11

8.1.2 Passenger Cabin Design:

Very light jet is a business jet aircraft, thus passenger cabin should be designed to get greater

comfort and luxuary. The following things were considered.

Table 8.1.2.1 Cabin Design

Fuselage parts and parameters Notes

Type of Cabin First Class

Door entry position Forward end of the aircraft

Door type Retractable doors with fixed steps

Door dimension 24in x 48in –Standard value for business

jets taken from roskam part III, from

chapter 3, fuselage and cargo hold

dimensions for transport jets

Window postion This depends on the frame postion and

not the passenger seating postions.

However for such small airplanes it is

dependent on passenger seating positions.

Window type Windows should be oval or circular in

shape to reduce the stess at the corners.

Window dimension 14in x 10in, – Standard value for

business jets taken from roskam part III,

from chapter 3, fuselage and cargo hold

dimensions for transport jets

Seat dimension Standard dimensions for a first class

passenger were taken from roskam part


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III, chapter 3, Definition of seat

dimensions, table 3.1

Number of galleys One – This depends on number of

passengers. In this case it is for 6

passengers

Galley postion Forward Galley

Galley dimensions 24in x 24in – Standard dimension taken

from roskam part III, chapter 3, galley,

lavatory and wardrobe layouts, table 3.6

Number of wardrobes One – This depends on number of

passengers. In this case it is 6 passengers

Wardrobe postion Forward Wardrobe

Wardrobe dimensions 24in x 15in – Standard dimension taken



Number of lavatories One – This depends on number of

passengers. In this case it is 6 passengers

Lavatory position Aft Lavatory

Lavatory dimensions 30in x 26in – Standard dimension taken



Baggage compartment Space left out in the aft fuselage (cone

end) is used for baggage

Baggage door position Door is positioned on aft end of the

fuselage after the lavtory compartment.

Baggage door dimension 28in x 33in - Standard dimension taken

from roskam part III, chapter 3, fuselage

and cargo hold dimensions.

Aisle width It should be between 20 to 28 inches. In


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our case we selected 14inches – The

reason being passengers are seated for

most of the time during flight and also to

reduce the over all diameter of the

fuselage.

Aisle height 76inches – Standard dimension for first

class passenger cabin design, from the

book , Aircraft Design, Daniel Raymer

Headroom 65inches -- Standard dimension for first

class passenger cabin design, from the

book , Aircraft Design, Daniel Raymer

Thickness of the fuselage 1.5 inches, this is a standard value for

structure of business jets, taken from

roskam part II, chapter 4, design of

cockpit and fuselage layouts, page 109

Bulkheads 2 bulkheads of 2in thickness are used,

one to separate cockpit and passenger

cabin area other to separate passenger

cabin area and lavatory.

Aft fuselage cone angle 15 degrees

For the final output of our design, refer chapter 11

8.2 Wing Design

Wing platform design, wing sizing and locating lateral control surfaces

1- After calculating Wto and matching diagram the following data are available

Wing area (S) (sq ft) Aspect ratio (A) Wing span (b)

375 7.5 53


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2- A low wing is considered to be the most appropriate for the designed Business Jet

(Biz)

3- The sweep angle of the Biz is selected to be suitable to the critical Mach number

M=0.8. The cruise speed lift coefficient can be estimated from the following equation

CLcr =(Wto -0.4Wf)/q.S

CLcr= (8625-0.4*2070)/(1/2*0.00056*(0.8*968.1)^2)*375=0.125

If a supercritical airfoil is used, then from fig (6.2 Roskam’s book part II) the

value of sweep angle of 25 deg and thickness ratio value of 0.12 for root and 0.11 for

wing tip are acceptable.

4. Choose the airfoil type: NACA 4412 with thickness ratio is 12

Figure 8.2.1: The selected Airfoil shape

5. Choose the taper ratio:

From table 6.5 (Roskam’s book part II), which is for Biz statistics data, the taper ratio

of 0.35 is chosen.


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Source: (Raymer)

6.Typical aileron dimension for Biz: the inboard ailerons will run along the wing from

0.7b/2 to 0.86b/2. The chord ratio is 0.25 (The data come from table 8.5a,b Roskam

book Part II).


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Table 2: Horizontal tail volume and elevator data

Resource (Raymer)

7. Define the front spar line of the wing: The value C=7.62 is defined and then C/4=


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1.9. The position of the front spar line is defined as 1.9/7.62*C=0.25*C.

8. Calculate the rear spar line: The inboard aileron chord ratio =0.25, then the position

of the rear spar line is defined as (1-0.25-0.005)*C= 0.745*C.

9. Compute the wing fuel volume:

The wing fuel volume can be calculated by the following formula

Vwf=0.54(S^2/b)(t/c)r[1+λw*τw^1/2 + λw^2*τw ]/(1+ λw)^2

Where τw =(t/c)t/(t/c)r= 0.92.

After calculation the value of wing fuel volume is 136.64 (ft^3).

10. Consider whether the amount of fuel of 2070 (lbs) can fit the fuel volume or not.

The volume required is of 2070/43.056=48 (ft^3) (This is because 1000lb occupies

20.8 fl^3). Thus, the wing has sufficient fuel volume.

11. Define the dihedral angle: The dihedral angle of the Biz is of 3 deg which is

reasonable.

12. Define the incidence angle and twist angle: The incidence angle of 1.5 may be

accepted and no twist angle.

13. Dimensioned drawings are followed by the following input data of the Biz wing.

Table 8.2.4 Data of the Biz wing

Parameters Symbol Units values

Wing area S ft^2 375

Aspect ratio A 7.5

Wing span B Ft 53

Sweep angle ∆c/4 Deg 25

Wing taper ratio λ 0.35

Wing tip Ct Ft 3.67

Wing root Cr Ft 10.48

Mean aerodynamic chord C Ft 7.62

MAC position Y Ft 11.123

Wing fuel volume Vwf ft^3 136.64


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Dihedral angle Г Deg 3

Twist angle T Deg 0

Angle of incidence i Deg 1.5

Root thickness ratio (t/c)r 0.12

Tip thickness ratio (t/c)t 0.11

Determining clean CLmax and sizing high lift divices

1. The values of required maximum lift coefficient are

CLmax CLmaxTO CLmaxL

1.8 2.1 2.5

These values are assumed for climb sizing calculations. It is not essential to be

met.

2. Verifying that the existing wing platform can produce a value of CLmaxw, which is

consistent with the required value of CLmax.

- Compute the Raynol’s value for the wing root and wing tip.

Rnr = 14.033.10^6

Rnt = 4.9.10^6

- From the figure 7.1(Roskam’s book part II), with (t/c)r =0.12 then Clmaxr =1.9, (t/c)t

=0.11 then Clmaxt =1.65.

- The Clmaxw can be compute as the following

Clmaxw =Kλ(Clmaxr+ Clmaxt)/2; Kλ =0.4

Clmaxw =1.7

- Correct Clmaxw with the sweep angle 25 deg

Clmaxw =1.7*cos(25)=1.57

CLmax =1.57/1.05=1.5

3. Determine the incremental values of maximum lift coefficient which need to be

created by the high lift devices.


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For take-off: ∆ CLmaxTO=1.05(CLmaxTO- CLmax)=1.05(2.1-1.8)=0.315

For landing: ∆ CLmaxL=1.05(CLmaxL- CLmax)=1.05(2.5-1.8)=0.735

From these values the Fowler flap may be collected.

4. Compute the required incremental section maximum lift coefficient with the flaps

down

∆ Clmax= ∆CLmax.(S/Swf)/Kλ

Where Kλ =[(1-0.08cos^2(∆c/4)).cos^3/4(∆c/4)]=0.878

- Assume that .(S/Swf)=0.6 and 0.8, then the calculation will be

Take-off flaps Landing flaps

S/Swf 0.6 0.8 0.6 0.8

∆ Clmax 0.215 0.287 0.503 0.67

5. Compute the required value of incremental section lift coefficient ∆ Cl, which the

flaps must generate and relate this value to flap type, flap angle and flap chord.

∆ Clmax=(1/K) ∆ Clmax

Assume that

+ The flap to chord ratio Cf/c=0.3

+ The flap deflection angle : σfTO=30 deg and σfL=40 deg.

+ we also collect Fowler double slots, then from fig (7.4) (Roskam’book part II):

Cf/c=0.3, K=0.94, then the results are

Take-off flaps Landing flaps

S/Swf 0.6 0.8 0.6 0.8

∆ Cl 0.23 0.305 0.535 0.713

+ The flaps may be designed to run from 0.25b/2 to 0.7b/2, then the S/Swf can be

computed as the following.

S/Swf =(η0-ηi)(2-(1-λ)( η0+ηi))/(1+λ)=

=(0.7-0.25)(2-(1-0.35)(0.7+0.25))/(1+0.35)=0.5225


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6. The summery of flap data for dimensioned drawings

Table 8.2.5


Flap to wing area ratio S/Swf 0.5225

Take-off deflection angle σfTO deg 30

Landing deflection angle σfL deg 40

Length l ft 11.925

Flaps Chord ratio Cf/c 0.3

7. The summery of aileron data for dimensioned drawings

Table 8.2.6


Length l ft 4.25

Ailerons Chord ratio Ca/c 0.25

8. The summery of wing tips data for dimensioned drawings

Table 8.2.7 Wing tips data for drawings


Type: Winglet

Upper fixed angle σ deg 15

Under fixed angle σ deg 30

Hight h ft 1.25

Root length Cr ft 3.67

Tip length Ct ft 0.92


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Empennage design

1- The following table shows value coefficient and control surface size data of

comparable business jet. The data of the new business jet will be collected based on

them.

Table 8: Statistics of available business jet

Aircraft type Vhbar Se/Sh Vvbar Sr/Sv

Falcon 10-259 0.69 0.2 0.063 0.32

Falcon 20-440 0.65 0.22 0.063 0.23

Cessna citation 500 -260 0.73 0.29 0.081 0.36

Cessna citation II-323 0.64 0.36 0.062 0.34

Cessna citation III-312 0.99 0.34 0.86 0.3

Average 0.74 0.28 0.071 0.31

2- For the very light business jet the data are chosen as following

Table 9: The data for VLJ vertical and horizontal tail

Vhbar Se/Sh Vvbar Sr/Sv

0.7 0.25 0.065 0.27

The reason for the selection is to apply flexible static stability combined with a digital fly by

wire flight control system.

3- Compute the geometric data for horizontal and vertical tail

Vh= Vhbar.S.C/xh

Vv= Vvbar.S.C/xv

S=375 ft^2, xh/C=2.5, xv/C=2.5

Then Vh=105 ft^2, Vv=67.8 ft^2

The following table shows the dimensions for horizontal and vertical tail of Biz

Table 10 : The data for drawings of vertical and horizontal tail


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Parameters Symbol Units Horizontal Vertical

Aspect ratio A 4.5 1.5

Sweep angle ∆ Deg 35 45

Taper ratio Λ 0.45 0.5

Air foil NACA 0009 NACA 0009

Dihedral angle Г Deg 2 90

Inc-angle I deg -3.5 0

Area S Sqft 105 67.8

Span B Ft 21.73 10

Root chord Cr ft 6.66 9.04

Tip chord Ct ft 3 4.52

Mean aero line Cbar ft 5.1 ft

Elevator Cr/ Ct 0.36-0.26

Rudder Cr/ Ct 0.35-0.31

4- The drawing of the tail as followed at the Figure Reference Chapter 11

Propulsion selection and integration

1- The mission specification of the Biz specifies that two High By Pass (HBP)

turbofan are to be used


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Figure 2: Engine envelope for Business jet

2- From the results of weight calculation and matching diagram the required thrust is

Tto =0.381.8625=3286 (lbs).

3- Two engine are used, so the maximum required thrust for each is 1643 (lbs).

4- From the research and requirements the following engine may be collected from

the given catalogue.

Table 11: The data of Williams-FJ33-418 M engine

Parameters Symbol values units

Engine type Williams-FJ33-418

M

Thrust T 1800 lbs

Specific fuel

consumption

SFC 0.486 lbs/lbs/hour


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Bypass ratio α 3.28

Dry weight Wd 310 lbs

Length Le 47.9 in

Fan diameter Df 17.3 in

Maximum diameter Dm 19.03 in

5- The selected engine can be scaled so that it may be fit the designed Biz

- Scale factor: SF=1643/1800=0.913

- Apply the principle of scale the following data of required engine can be obtained

- L=47.9.(0.913)^(0.4)=46.2 (in)=3.85 (ft)=1.1735(m)

- D=19.03.(0.913)^(0.4)=17.37 (in)=1.4476 (ft)=0.4412(m)

- W=310.(0.913)^(0.4) =298.92 (lbs)

And now the new scaled engine data are available

Table 12: The data of scaled engine for VLJ

Parameters Symbol values Units

Engine type Williams-FJ33-418

M

Thrust T 1800 lbs

Specific fuel

consumption

SFC 0.486 lbs/lbs/hour

Bypass ratio α 3.28

Dry weight Wd 298.92 lbs

Length Le 46.2 in

Fan diameter Df 17.3 in

Maximum diameter Dm 17.37 in

6- Sizing for the inlet

- Engine diameter =1.4476 (ft)

- Front face diameter =0.8.1.4476=1.158 (ft)


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- From the fig(10.16- Ramer book ) the capture area to mass flow ratio as following .

- M=26.(1.158)^2=34.86 (kg/s)

- The design mach number is 0.8 then from fig 10.16 the value of Ac is determined as:

Ac=0.0251.34.86=0.875 (sq ft).

-

Figure 3: The acceptable value of Capture area

7- Sizing for nozzles

The required exit area of nozzle

Nc=0.7.Ac=0.7.0.875=0.6125 (sq ft).

The capture and nozzle area are suitable for initial layout and rough analysis.

The following is summery of inlet and nozzle data.

Parameters Symbol Values Units

Capture area Ac 0.875 sq ft

Mass flow M 34.86 kg/s

Nozzle exit area Nc 0.6125 sq ft

8- Propulsion integration:


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Installation position Aft-fuselage mount

Features - Using with T-tail

- Minimize the wing interference effects of wing

–mounted engines

- Using short landing gear

- Increasing noise at the rear of the Biz

- Aft-mounting of the engines tends to move the

center of gravity aft which requires shifting the

entire fuselage forward relative to the wing.

- Reduce tail moment arm and raises the amount of

fuselage forward of the wing.

- Lager vertical tail and horizontal tail are required

Aft-nacelle

Requirements

A nose –up pitch of 2 deg is required

A nose outward cant of 2 deg is required

9- The installation of the engines meets the requirements of geometric clearance

during take-off, FOD characteristics , crash, and low speed approach.

10- The drawing of engine installation is shown at Figure Reference chapter 11.

8.3 Landing Gear Design

(1) Type of landing gear I

The cruise speed is about 0.8~0.85 mach, which is significantly more than 150 knots. If

considering the drag to the aircraft, the retractable landing gear is selected.

(2) Type of landing gear II


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For typical business jet, the tricycle type of landing gear is selected.

Figure 8.1.1 Landing gears type

(3) CG calculations

Refer to “Chapter 9, Weight and Balance Analysis”.

(4) Verifying the weight and balance

There are two criteria is needed to be verified of the design, one is the angle A and B which is

shown in figure 8.1.2 while the other is the angle Ψ which is shown in figure 7.2.2.

Figure 8.1.2 Angle Criteria I

Where the angle A must be either greater than B or A must greater than 15 degree. However

CG

B A

a

b


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the angle A can be calculated as:

Therefore the design can meet the tipback angle requirement.

Figure 8.1.3 Angle Criteria II

However, as Ψ must be smaller than 55 degree, in this case, we define the angle to be 50

degree. And after calculating, the distance between two main gears is 120 inches.

(5) Strut length

The minimal strut length should meet the angle requirement when the aircraft takeoff and

lands. The diagram can be shown as follows:

Figure 8.1.4 Strut length

As can be seen from the diagram above, the angle A should be smaller than the tipback angle,

Ψ

CG

A

d


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which is defined as 15 degree. In this case, we define the angle to be 13 degree. And the

minimum length of the strut can be found.

Hence,

(6) The disposition of the main gears

There are three options for selecting the main gears position:

� In the fuselage:

� In the fuselage-podded:

� Wing/fuselage junction

Figure 8.1.5 Disposition of the main landing gears


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For the first option, the fuselage of the very light jet is not large enough to retract two gears

and the scenario is not applicable in the VLJ design.

For the second option, it will use large spaces on the both sides of the aircraft and therefore

the wings are hard to be placed. Another consideration is the costs of the idea. Extra structure

design and material must be used.

For the third option, which is suitable for placing the gears, has made use of the space by a

reasonable and smart way. And finally this scenario was selected.

(7) Positioning of the nose gear:

The conventional retraction of the nose gear can be selected for the design. Considering the

safety, the forward retracting gear is selected. It is shown as follows:

Figure 8.1.6 Disposition of the nose landing gear

(8) Static load per tyre calculation

By calculating the static load per tyre, we are able to select the minimum tyre size for

maximum weight. However the static load can be calculated by


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Where the parameters are shown in the diagram below

Figure 8.1.7 Static load analysis

However the results can be tabulated as

Table 8.1.1 Static load analysis

Values (lbs)

Maximum static load (main) 4128

Maximum static load (nose) 678

Minimum static load (nose) 370

Dynamic braking load (nose) 1415

Applying the equations below, the dimension can be found through the values in the table

above


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For business jet, A=2.69, B=0.251

Therefore the dimensions of the tires are

Table 8.1.2 Diameter of tires

Diameter

Main gear (max) 24 inches

Nose gear (max) 16 inches

Nose gear (min) 12 inches

From the type VII catalogue, the suitable tyre can be found

Main gear:

Nose gear:

Figure 8.1.8 Diameter of the tires

The specifications of the tires are listed in the following table:

Table 8.1.3 Tires specifications

Gears Dt × bt (in.) PSI nmt

Main gear 24 × 5.5 355 1

Dt=24

bt=5.5

Dt=16

bt=9.5


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Nose gear 9.5-16 90 1

Note: GIR is the gear landing ratio

(9) Shock absorber

The stroke (shock absorber deflection) can be calculated as:

Where St is half of the diameter minus the rolling radius, therefore

Where the values are:

Table 8.1.4 Shock absorber

Definition Values

Vvertical 180sin(3) 9.4 ft/s

g constant 32.185 ft/s2

η Tyre efficient 0.47

ηT FAR23 0.62

Ngear FAR23 3.0

ST (0.5)(24-10.6) 6.7

In this table, we assume the landing angle is 3 degree, and assume all the values according to

FAR 23; however the ST is half of the diameter of the tyre minus the rolling radius.

Therefore the shock deflection can be calculated as:

The result is quite a reasonable value for the stroke deflection.


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Chapter 9 9. Weight and balance analysis

As first sketch, the weights of components are not given, therefore estimations must be found

based on the statistics.

The structure weight can be broken down into four parts, which are fuselage weight, wing

weight, empennage weight and landing gears weight. For a business jet, which is under the

subsonic passenger (small) category of the aircrafts, the weight of other components can be

found as:

There are two important categories of CG should be found. One is the most forward CG

while the other is the aft CG. The nose of the aircraft is the selected datum. However the

values can be tabulated (the CG of every part of the aircraft) as the following table:


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Table 9.1.1 Components CG I

Component Percentage of weight Weight x Wx z Wz Wing 30% of We 1597.5 250 399375 25 39937.5 Fuselage 32% of We 1704 250 426000 48 81792 Empennage H.T. 66.25 570 37762.5 105 6956.25 Empennage V.T. 5% of We 200 450 90000 87 17400 Gear M.G. 480 420 201600 13 6240 Gear N.G. 10% of We 52.5 112 5880 12 630 Engines 11% of We 585.75 445 260658.75 86 50374.5 Fixed equipment 12% of We 639 278 177642 45 28755

We total = 100% 5138 293.0

5 1598918.2

5 43.5

8 232085.2

5 Fuel 2012 220 442640 25 50300 TFO 40 160 6400 Pilot 175 98 17150 43 7525 Passengers 1050 270 283500 45 47250 Baggage 210 410 86100 65 13650

8625 282 2434708.2

5 40.8

4 350810.2

5

Note: x is the distance from the front of the aircraft to the CG (length), z is the distance from

the ground to the CG (height).

If we summed up the weight for each operation configuration, the weights and CG of

different configuration (in terms of fuselage station) can be found:

Table 9.1.2 Components CG II

weight x We 5138 293.05 We+TFO 5178 310.027 We+TFO+Pilot 5353 303.095 We+TFO+Fuel 7190 284.834 We+TFO+Fuel+Passenger 8240 282.944 We+TFO+Fuel+Passenger+Pilot 8415 279.098 We+TFO+Fuel+Passenger+Pilot+Bag 8625 282.285 We+TFO+Passenger+Pilot+Bag 6613 301.235


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Note: x is the distance from the front of the aircraft to the CG.

Hence, the CG envelope is plotted as:

275 280 285 290 295 300 305 310 315

5000

5500

6000

6500

7000

7500

8000

8500

9000

Wei

ght (

lbs)

F.S. x (inches)

WeWe+PILOT We+TFO

+Fuel

+PAX.

+PILOT

WTO

-Fuel

Figure 9.1.1 CG envelop

From the diagram above, the most forward CG and aft CG can be found. As can be seen, the

most forward CG occurs at x=318 inches, which the weight is 5322 lbs. The aft CG occurs at

x=328 inches, which the weight is 8622 lbs. The results can be shown as follows:

� Forward CG: ,

� Aft CG: ,

Hence the CG range is 10 inches which is quite a typical value for the very light business jet.


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Chapter 10 Conclusion

Through all the analysis above, we come up with the conclusion which shows the advantages

and disadvantages of the very light business jet. The discussion of the market futures and

manufacturer notes are the main considerations in this part.

For the advantages, there is dissatisfaction with other forms of transportation due to increased

hassle associated with commercial airline and automobile travel. With the introduction of VLJs

the situation will be pacifying

Low purchase price and operating cost

There will be access to satellite airport or regional airport. The reason being VLJ have shorter

take off and landing distances and do not require all the amenities that a large transport

aircraft requires

On the other hand, for the disadvantages, improvement in infrastructure is necessary for

linking satellite airports with main airports, which is a overhead with VLJ operating in

satellite airports

Pilot training and insurance requirements can be burdensome. VLJs are usually certified for

single pilot operations and hence necessary training needs to be imparted. Most of the

customers ask for two pilots to ensure safety and peace of mind.

Production constraints may cause delay in deliveries.


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Problems associated with standards. As this is a new class of aircraft there may be many

standards which are not specified by FAA or under development, hence certification process

becomes very tedious.

Due to the limited capacity, the VLJ cannot fly a long distance. Ideas on how to increase the

range of the VLJ business jet would probably needed.

Finally, the output and design of the aircraft can be listed (dimension)

SPECIFICSTION OF THE AIRCRAFT

Design Point Parameters Values

Weight Takeoff weight 8625 lbs

Empty weight 5138 lbs

Fuel weight 2053 lbs

Payload weight 1435 lbs

Wing loading 20.82 psf

Power loading 0.381

Performance Cruise speed 0.8 mach

Max. speed 0.85 mach

Climb rate 477.24 ft/sec

Cruise altitude 41000 ft

Range 2000 nmi

Takeoff distance 650 m

Landing distance 700 m

Main wing Area 375 ft2

Span 53 ft

Root chord 6.66 ft

Tip chord 3.67 ft

Aero foil NACA 4412


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Horizontal tail Area 105 ft2

Span 21.73 ft

Root chord 6.66

Tip chord 3

Aero foil NACA 0009

Vertical tail Area 67.8 ft2

Span 10 ft

Root chord 9.04 ft

Tip chord 4.52 ft

Aero foil NACA 0009

Fuselage Length 530 inches

Max. diameter 83 inches


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Chapter 11 Drawings

1. 3-view drawing

2. Manufacturer drawing

3. Working drawing

4. Figures of 3D modelling


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5. Figures of 3D modelling:

COCKPIT


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WING


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FUSELAGE


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TAIL


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AIRCRAFT ASSEMBLED


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Reference: United States Government Accountability office (GAO): Very light jet several Factors Could Influence Their Effect on the National Airspace System , August 2007. Embraer Market Outlook 2009-2028 Dr. Jan Roskam: Airplane design Part I,II,III,IV,V, DARcorporation 2004 Dr. Maziar Arjomadi: Aircraft design 2009. E. Torenbeek: Synthesis of subsonic airplane design. Anderson, J. 1999 “Aircraft Performance and Design” McGraw Hill, USA. Arjomandi, M, 2008, “Aircraft Design Lecture Notes’, University of Adelaide, Australia Barnes and Mccormick, 1979, ‘Aerodynamics, Aeronautics and Flight Mechanics’, Wiley & Sons. Beer & Johnston, 1999, ‘Vector Mechanics for Engineers’, McGraw-Hill. Brandt S.A, 2004, ‘Introduction to Aeronautics: A Design Perspective’, American Institute of Aeronautics. Raymer, D. 2006 “Aircraft Design: A Conceptual Approach” AIAA, Reston, Virginia Conklin & de Decker, SH&E Research VLJ magazine http://www.verylightjetmagazine.com/ www.kewljets.com Tools used for the project: CATIA & Javafoil

21st century business jet

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