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    AAE 451

    System Requirements Review

    February 11, 2010

    Team 1

    Alex Mondal

    Beth Grilliot

    Brien Piersol

    Heath Cheung

    Jason Liu

    Jeff Cohen

    Jeremy Wightman

    Kit Fransen

    Lauren Hansen

    Nick Walls

    Ryan Foley

    Tim Fechner

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    TABLE OF CONTENTSEXECUTIVE SUMMARY................................................................................................................3

    MISSION STATEMENT .................................................................................................................4

    MARKET ANALYSIS .....................................................................................................................4

    CUSTOMERS ...............................................................................................................................7

    BENEFITS ................................................................................................................................................ 10

    COMPETITION...........................................................................................................................10

    CONCEPT OF OPERATIONS .......................................................................................................14

    REPRESENTATIVE CITY-PAIRS ................................................................................................................. 14

    DESTINATION FLEXIBILITY ...................................................................................................................... 16

    DESIGN MISSION .................................................................................................................................... 18

    MISSION SKETCH .................................................................................................................................... 19TYPICAL OPERATING MISSION................................................................................................................ 20

    SYSTEM DESIGN REQUIREMENTS .............................................................................................21

    ADVANCED TOPICS UNDER CONSIDERATION ...........................................................................22

    CABIN LAYOUTS ........................................................................................................................27

    SIZING ESTIMATES ....................................................................................................................31

    SUMMARY AND NEXT STEPS ....................................................................................................38

    WORKS CITED ...........................................................................................................................39

    APPENDIX A: AIRPLANE DATABASE ..........................................................................................42

    APPENDIX B: HOUSE OF QUALITY .............................................................................................43

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    EXECUTIVE SUMMARY

    The goal of the project is to design a business aircraft for the year 2020. Special

    considerations are to be made for the customers needs, which include environmental impact.

    It is expected that medium sized and long range aircraft will sell larger quantities than other

    classes of business aircraft between now and 2028. Currently there is a decreasing trend in

    sales of business aircraft due to worldwide economic downturn. Forecasts of market trends

    state that although the near future market is expected to shrink, the business aircraft market is

    expected to grow in the next 20 years. This market growth is projected to occur because of

    rejuvenated economies as well as expanding markets overseas.

    Although the majority of customers are expected to be from North America and Europe,

    the emerging economies in Asia are expected to play a pivotal role in general aviation

    purchases. In the future, customers will require an aircraft design that reduces both emission

    and noise pollution. As the world becomes more conscientious of the effect of burning fossil

    fuels in our environment, standards for aircraft efficiency will have a factor in how attractive an

    aircraft is to a customer.

    Evaluating the customer desires through means of a house of quality, we determined

    that fuel weight, range, and cruise speed are the greatest factors in the aircrafts design. In

    regards to the weight of the aircraft, we used a database of similar sized aircraft and

    computational algorithm in order to estimate the aircrafts weight. The equation for

    determining the gross and empty weight ratios evaluates based on aircrafts design

    consideration such as cruise Mach, thrust to weight, and aspect ratio along with the gross

    weight estimate. As air travel begins to expand prolifically, the importance of minimizing

    environmental impacts will better adhere to consumer desires. Coupled with the ability to

    provide rapid and flexible long distance travel, our aircraft is ideal for satisfying future air

    transportation needs.

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    MISSION STATEMENT

    To engineer a conceptual business jet solution capable of transporting esteemed

    passengers, in luxury, while adhering to NASAs N+2 environmental goals.

    In order to abide by NASAs N+2 environmental standards, our concept will provide

    reduced NOx emissions, reduced noise pollution, increased fuel efficiency, and an increased

    percentage of recyclable materials used in construction. These key topics will help address the

    primary concerns of environmentally conscious groups.

    MARKET ANALYSIS

    The market for business jets was examined in order to properly discern the most

    profitable business jet class to construct. Multiple trends throughout the market were

    observed from market studies. The first trend of the market is that more lightweight sized jets

    will be sold than the other classes of jets over the next 20 years. The second trend of the

    market is that the economic situation of Asian countries will remain at a level where aircraft

    purchase is an option for consumers. In addition to the Asian countries, America and Europe

    are expected to have an economic rise in the next 20 years. A third trend of the market is that

    consumers will continue to desire larger cabins and faster speeds, while now desiring an

    environmentally friendly aircraft.

    The medium and large-weight business jets are expected to be sold in larger quantities

    than the other types of business jets, as seen in Table 1.

    Table 1: Project Sales of Business Jets

    Aircraft Delivery Summary 2009-2018 2019-2028 Total

    Very Light Jets 2,616 3,525 6,140

    Small Business Jets 3,490 4,696 8,187

    Medium Business Jets 4,045 6,913 10,958

    Large Business Jets 3,418 5,787 9,205Business Jet Totals 13,568 20,921 34,490

    This projection takes into consideration the economic problems of the large countries as

    well as the assumption that more of the world will become more environmentally conscious in

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    the coming years. To illustrate these factors, a recent survey conducted by Bombardier stated

    that customers attach importance to:

    1. Time savings and convenience

    2. Direct access, even to remote destinations

    3. Relatively new aircraft adapted to customers personal tastes (colors and equipment)

    4. Easy booking, payment and service provision

    5. Safety of the jets and quality of the operators

    6. Usage concepts that do not require users to own the jet

    7. Avoiding public attention or criticism for using business jets

    Examining surveys conducted by aerospace companies, as well as market trends, formulates

    the conclusion that the long-range business jets will remain dominant within the market. As

    seen in Figure 1 below, although more medium-size jets will be sold, the net income will

    approximately be the same for all classes of jets. This is the reason our team has chosen a long-

    range class of business jet.

    Figure 1: Business Jet Forecast for 2009-2018(Bombardier Business Aircraft Market Forecast)

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    Within the long-range field of the business jets lies a competition with the commercial

    airlines as well as technological developments that threaten to obsolete the business jet.

    However, since the target customer is a proven base, the competition is factored into the

    number of planes sold per year. Due to the current state of the economy, commercial airlines

    may begin to encroach upon the business of jet providers; nevertheless, the business jet will

    still have its pool of buyers. As environmentally conscientious groups advocate more forcefully,

    the populous will demand that the transportation services become environmentally friendly.

    This will spur the business owners to indulge in new aircraft. The underlying concern that

    computer technology will become more prevalent in communication and more companies will

    hold internet conferences in lieu of traveling by business aircraft. However, it is evident that

    the availability of cost effective communications devices today has not halted production of

    long-range aircraft. Quite the contrary, the market projection for long range aircraft will nearly

    double in size over the next decade. Because of the capabilities of long-range business jets

    have the ability to fly trans-continental non-stop without refueling, a business can reach their

    destination of interest in an efficient amount of time.

    The size of the market, however, is not the only considerations when choosing the class

    of aircraft for the company to invest in. The competition in each market also affects the chance

    of selling aircraft. For the smaller, lightweight business jets, many companies have embeddedthemselves within the market. These companies include Bombardier, Gulfstream and Cessna.

    As for the long range market, companies such as Boeing, Airbus and Gulfstream compete for

    sales; even if they all do not sell business jets, the long range (trans-Pacific) flights compete

    between commercial flights and private ones. A sample of these companies can be seen below

    in Figure 2.

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    Figure 2: Business Jet Market Segmentation(Bombardier Business Aircraft Market Forecast)

    The conclusion made from inspecting the trends of the business jet markets is that the

    market will rise due to the stabilizing world economies. However, an economic crisis is not

    prominent everywhere. The economic situation in Asian countries such as China and Japan are

    not as poor as they are currently in the United States. In addition, more consumers from these

    countries are buying aircraft. This will to be a promising factor in the sales of business jets over

    the next decade. While sales forecasts are never absolute, there is a risk that the market for

    long range jets will decrease. Historical data, as well as a few major companies predictions,

    suggest the market will remain stable. Moreover, the expansion of businesses to countries

    outside of America is expected to cause a consistent market for the longer range jets.

    CUSTOMERS

    The 2009 Honeywell Projections, shown in Figure 3, show that the two greatest factors

    for current business jet owners to purchase an aircraft were age and the need for greater

    capacity. Age is the predicted number one reason for customers in North America and Europe

    to purchase a new aircraft. Older aircraft can be replaced by any new model so this does not

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    constrain our design. Additionally, Asia and the Middle East considered a bigger cabin to be a

    driving factor for a business jet. For this reason, designing a high-capacity business aircraft is a

    logical approach. As emerging economies like Brazil, China and India grow and become more

    stable, more business aircraft purchases will come from overseas. Therefore, the majority of

    the market will be looking to buy newer aircraft with large cabins.

    Narrowing down the market necessitates a more specific definition of who the

    customers are; the customers include: Large International Corporations, Fractional Providers,

    and Individuals. These customers have shifted away from North America, and primarily will

    focus on Asia. According to the FAA Aerospace Forecasts of the Fiscal Years 2009-2025,

    significant growth is expected in Asia and Latin America.

    The Asia/Pacific and Latin America regions will continue to have the worlds highest

    economic growth rates. These regions are expected to see their economic activity grow at

    annual rates of 4.4 and 3.7 percent a year over the forecast period. In Asia, China, with a

    population of 1.3 billion, is forecast to grow 7.7 percent a year, becoming the worlds second

    largest economy. India, with a population of 1.2 billion, is projected to see its GDP triple in size,

    growing at an average rate of 6.6 percent a year during the forecast period. The economic

    growth in Asia will fuel the use of the business jets. Bombardier produced a split of the

    Figure 3: Honeywell Jet Purchasing Survey (2009 Business Aviation Outlook - Honeywell)

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    billionaires in the world and it concluded that 13% of the worlds billionaires live in the

    continent of Asia. With China, India, and Japan all represented in the worlds billionaires,

    individuals will desire to purchase the business jets.

    Figure 4: Country split of Billionaires by Bombardier

    Currently, the Asian market is underrepresented in the business jet market. Due to

    economic growth and looser government regulations on business jet aircraft however, Asian

    companies will strive to improve their status. As stated earlier, the main reason that the

    business jet owners in Asia want to purchase a new business jet is cabin space. This is because

    larger cabins in these regions can be used as a status symbol when flying business jets. Even

    though the companies or individuals will not need to fly at maximum capacity, a larger jet

    equates to company wealth. The Asian market has not been fully realized in todays jet market;

    due to their economic growth, the amount of aircraft being bought is expected to be

    exponentially higher in 20 years.

    For customers beyond 2020, emissions and noise pollution will also be factors in

    purchases due to new environmental measures that are expected to be taken to curb the

    effects of climate change. One benefit of a business jet is the capability of using smaller

    airports; however these airports may have strict noise pollution laws, such as Teeterboro, New

    York. Therefore, the customer will need an aircraft that produces fewer emissions, both in

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    terms of noise levels and emissions. From the evidence above, it is determined that offering an

    aircraft capable of traveling overseas and the ability to carry the most passengers will help

    meet the needs of the 2020 customer and beyond.

    BENEFITS

    The designed business jet will be able to meet customers needs in ways that other business

    jets cannot. First, the business jet will provide a productive workspace to allow executives a

    reasonable environment to work. This would allow for less downtime during the flight as well

    as an incentive for the executives to buy the jet. A complete on-board computer system will

    also enhance the amount of work that can be completed while en route to other meetings or

    events. In order to ensure a working environment similar to that of an office, multiple

    commodities will be provided as a selling point for the jet.

    Second, the business jet will also be the most environmentally friendly in the industry.

    Measures will be taken to ensure the business jet will be fuel efficient with little emissions.

    Another requirement placed on the jet is the amount of recyclable material in the production of

    the jet. This is to ensure that the jet can be disposed of in an environmental fashion once it has

    been decommissioned.

    Third, the business jet will provide flexibility to the destinations that the jet can operate;

    this is unmatched by any other business jet. The business jet will have a take-off and landing

    distance that allows secondary airports to be used when flying in the United States as well as

    Europe and Asia. The ability to land at secondary airports will reduce the amount of time spent

    waiting at larger airports. The flexibility to land at smaller airports will also allow company

    executives to utilize airports closer to their final destination.

    COMPETITIONIn order to understand the market which will purchase this aircraft, it is important to

    consider current options which consumers have. Company executives can choose to fly on

    commercial airlines or to purchase fractional ownership of a jet. However, the main competitor

    with our aircraft will be business jets produced by other companies. There are several current

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    business jets and as well as jets under development with which the designed jet will compete;

    these business jets are shown in Table 2.

    Table 2: Comparison of Business Jets

    Aircraft Name No of Passengers Market Price (Million $) Still-Air Range (nmi)

    Bombardier Global 5000 17 32.95 5200Bombardier Global Express 19 45.5 6325

    Gulfstream G500 19 38 5800

    Gulfstream G550 19 46 6750

    Gulfstream G650 18 --- 7000

    Embraer Legacy 600 16 23.6 3361

    Dassault Falcon 7X 14 39 5700

    Dassault Falcon 900DX 12 31.95 4100

    In addition to the aircraft listed in Table 2, there are several other categories of jets

    which businesses have the option of purchasing. The initial step in designing a long range

    business jet is to analyze the business jets which currently exist or are being developed. The

    aircraft listed inTable 2 will be discussed further in this section to determine the distinguishing

    features each aircraft provides. In order for a new jet to compete with these aircraft, the jet

    must at least match the qualifications and amenities provided by the competition.

    The Bombardier Global business jets are designed to be super large to ultra-range jets.

    The two jets in Bombardiers Global section are the Global 5000 and the Global Express XRS. As

    seen from the costs shown inTable 2,the Global Express XRS is a more high-class jet than the

    Global 5000; but both have key features they market. The Global 5000 business jet has the

    widest cross section, the longest seating area, and the option to have a stateroom.

    Additionally, the Global 5000 can fly from Continental Europe to the West Coast without

    stopping. The Global Express XRS offers a built in private stateroom, temperature zones for

    personal comfort, lowest cabin altitude, windows which improve passengers range of vision up

    to 40 to 44% more usable area than the nearest competitor, and an optional humidifier to

    reduce passenger fatigue.

    Similar to Bombardiers Global jets, Gulfstream Aerospace Corporation produces high-

    end luxury jets. The three jets which will likely compete with this new business jet are the

    G500, G550, and the G650. Each of the Gulfstream jets allows the ability for the customer to

    choose the passenger layout, has three temperature zones, and continually supplied 100%

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    fresh air. The G500 has an advanced flight deck, long rang and impressive speed. The

    Gulfstream G550 provides a fax machine, printer, wireless local area network, satellite

    communications, comprehensive entertainment show, two galleys, two lavatories, and the

    option for a crew rest area. The Gulfstream G650 flies at the fastest cruise speed and the

    furthest range of any business jets, the cabin is eight feet wide and six feet high, 28 windows, a

    five year parts and labor for production components warranty, 20 year parts and labor on the

    structure, and 2 year parts and labor for the interior components.

    The Embraer Legacy 600 is a mid-priced jet which has an engine start up time of 10

    minutes, three cabin zones, six foot tall cabin. This jet is marketed as having the largest cabin in

    this category. Dassault Falcon jets are distinguishable by the three-engine design used on these

    jets. The Dassault Falcon 900DX utilizes the shortest takeoff distance of any other Falcon in

    production, consumes 40% less fuel than its nearest competitor, and has a high landing weight

    to allow for fully loaded short hops with as well as a long range mission without refueling. The

    Dassault Falcon 7X flies at a high speed and features a long range, and includes quieting

    acoustics for customer satisfaction.

    In order to ensure our design can surpass the competition, we will have to provide

    additional benefits to avoid only imitating a design already in production. Although we would

    like to exceed the competition in every aspect of the business jet by providing the same rangeand speed while offering the same comfort and volume, we understand that this is simply

    impossible with the design trade-offs that need to be made. Thus, the design will be

    competitive through offering a business jet that is environmentally friendly, fuel efficient, and

    flexible in landing destinations.

    The jets displayed inTable 2 were used to ensure the business jet being designed follow

    the current trends.Figure 5 shows the trend between the market price and the range of the

    business jet. The blue oval shows where the jet is forecasted to lie. This price estimatedepends upon several factors and assumptions. It is assumed that although the material used

    for the jet is currently new, it will be fully developed by the jets time of release. Furthermore,

    it was assumed that the manufacturing costs for the material will be fairly low, since the

    material will be in development. Additionally, a developed engine will be used; therefore, no

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    funding needs to go towards research and development of an engine. The last major

    assumption is that a high number of jets will be sold. This allows a lowering of the price of each

    jet. The designed business jet is projected to enter the market at the approximate price range

    of a Bombardier jet; however, a more precise pricing will be calculated later on in the design

    process.

    Figure 5: Market price as a function of aircraft range.

    Figure 6 shows the trend between the number of passengers and the range of the jets

    shown inTable 2. Currently, the designed business jet will have a maximum passenger capacityof 19; this places the jet even with the competition while still remaining within the limit of 20

    passengers set by the FAA. As seen inFigure 5 andFigure 6,the aircraft closest to the designed

    business jet are the Bombardier Global Express and the Gulfstream G550.

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    Figure 6: Number of passengers versus range of the business jet.

    The jet designed by the analysis in this paper will account for the benefits of each of the

    competition of business jets listed above to ensure a proper market share. The designed

    business jet will have four main selling points; customer comfort, productivity, environmental

    safety, and the ability to be flexible in destination choice.

    CONCEPT OF OPERATIONS

    REPRESENTATIVE CITY-PAIRS

    Current economic predictions show that the Asian markets will continue to grow rapidly

    through the next 20 years. Economists have determined that there are eight main countries

    whose economies are on the rise. These countries are: China, Indonesia, Papua New Guinea,

    Thailand, Taiwan, the Philippines, Singapore, and Malaysia. In addition, many economists

    believe that these countries will continue to contribute to the economic growth over the next

    few decades. The designed business jet will aim to appeal to this ever growing market along

    with customers in North America and Western Europe.

    To appeal to the United States market, the jet must be able to fly trans-Atlantic and

    trans-Pacific flights without layover. Table 3 shows the ability to fly both trans-Atlantic and

    trans-Pacific from Los Angeles, California. Since trans-Atlantic flights can be flown from Los

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    Angeles, it is possible for the business jet to fly trans-Atlantic from any destination city in the

    domestic United States.

    Table 3: Trans-Atlantic and trans-Pacific capabilities out of Los Angeles.

    Departure City: Los Angeles, California

    Arrival City: Code: Still-air Range (nmi):

    Beijing, China PEK 5449

    Hong Kong HKG 6332

    Tokyo, Japan NRT 4783

    Wewak, Papua, New Guinea WWK 5949

    Florence, Italy FLR 5415

    Paris, France CDG 4940

    Barcelona, Spain BCN 5150

    Zurich, Switzerland ZRH 5175

    In order to display the useable secondary airports,Table 4 shows the distances from

    domestic secondary airports to secondary airports in trans-Atlantic destinations.

    Table 4: Secondary Airport trans-Atlantic Capabilities.

    Trans-Atlantic Flights Code: Code: Still-air Range (nmi):

    Daytona Beach, FL to Milan, Italy DAB LIN 4220

    Daytona Beach, FL to Nice, France DAB NCE 4175

    Teterboro, NJ to Rome, Italy TEB CIA 3745

    Dekalb Peachtree, GA to Nice, France PDK NCE 4125

    Dekalb Peachtree, GA to London, England PDK LTN 3650

    Fort Lauderdale, FL to Geneva, Switzerland FXE GVA 3980

    Fort Lauderdale, FL to Paris, France FXE LBG 4160

    For the business jet to appeal to Asian markets, it must be able to perform flights from

    one Asian country to another. Shenyang, China is chosen to display the range of the jet to more

    southern cities in Asia. Shenyang was chosen because it is the northernmost major city in

    China. Any city south of Shenyang can be used as a departure city to reach any of the arrival

    cities shown below; and these cities include Beijing, Delhi, Hong Kong, and Bangkok.Table 5

    displays the range from Shenyang to each city listed as an arrival city; and demonstrates the

    ability to fly around Asia out of any of the cities listed above.

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    Table 5: Asian flights out of Shevang

    Departure City: Shenyang, China

    Arrival City: Code: Still-air Range (nmi):

    Wewak, Papua New Guinea WWK 2960

    Bandung, Indonesia BDO 3070

    Bangkok, Indonesia BKK 2075Sydney, Austrailia SYD 4830

    Dubai, United Arab Emirates DXB 3475

    Delhi, India DEL 2390

    In addition to Asian travel, the business jet must also be able to fly from Asia to Europe.

    Tokyo, Japan is chosen to display the range of the jet to European cities. Tokyo was chosen

    because it is the easternmost major city in Asia. Any city west of Tokyo can be used as a

    departure city to reach any of the arrival cities shown below; and these cities include Beijing,

    Delhi, Hong Kong, and Bangkok. Table 6 displays the range from Tokyo to each city listed as an

    arrival city; and demonstrates the ability to fly from Asia to any city in Europe.

    Table 6: European Flights out of Tokyo

    Departure City: Tokyo, Japan

    Arrival City: Code: Still-air Range (nmi):

    Florence, Italy FLR 5305

    Paris, France CDG 5270

    Barcelona, Spain BCN 5670

    Zurich, Switzerland ZRH 5205

    Amsterdam, The Netherlands AMS 5060Moscow, Russia SVO 4070

    London, England LHR 5205

    The capability for the business jet to travel long distances without stopping is extremely

    important to the customer satisfaction of the jet. The information presented above does not

    completely cover the flight possibilities of the business jet, but it does show the distances the

    jet will be able to fly. Much thought went into the city-pairs described above and these cities

    were determined to be the most important to customers. With this business jet, the customer

    will be able to fly anywhere in the world.

    DESTINATION FLEXIBILITY

    The designed business jet will have the ability to land at secondary airports and major

    airports. The largest constraint on which airports the jet can land at is the length of the runway

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    that the business jet requires to operate. To ensure the aircraft can operate at many airports,

    the takeoff distance of the jet must be lower than the amount of runway which various airports

    already have built. Major airports are not included in this analysis because our aircraft is

    smaller and quieter than commercial aircraft, thus expected to fit well within the constraints

    set at large international airports.

    It is important for a business jet to be able to land at major airports. However, it is much

    more desirable for the jet to be able to land at regional airports. Landing at regional airports

    will reduce the time which a jet waits in line to land compared to major airports. This ability

    will allow the passengers onboard the flight to spend less time traveling to meetings. In

    addition, landing at regional airports allows a faster turnaround time; the customers will be

    able to get in and out of airports quicker than the competition that cannot land at secondary

    airports. Examples of the competition include the Gulfstream G550 which has a takeoff distance

    of 5900 ft and the Global Express which has a takeoff distance of almost 6200 ft. With a target

    takeoff distance of 4700 ft, the designed jet will be able to utilize airports which these other

    jets cannot. Examples of the airports which the jet will be able to use and the competition

    cannot are shown inTable 7.

    Table 7: Secondary airport runway lengths

    City: Code: Max Runway Length (ft):

    United States:

    Daytona Beach, FL DAB 5000

    Santa Ana, CA SNA 5701

    Fort Lauderdale, FL FXE 6000

    Dekalb Peachtree, GA PDK 6000

    Cincinnati, OH LUK 6100

    City: Code: Max Runway Length (ft):

    Europe:

    Bourges, France BOU 5000

    Florence, Italy FLR 5425

    San Sebastian, Spain EAS 5700

    Copenhagen, Denmark RKE 5700Lubeck, Germany LBC 5900

    Overall, the destination flexibility which can be provided by this business jet far

    surpasses the flexibility by the competition. This business jet will be able to accommodate

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    customers from across the world by providing a long range jet which is environmentally friendly

    and has more destination flexibility than any other jet can provide.

    DESIGN MISSION

    As discussed previously, the benchmarks set for our design represent a long-range

    business aircraft. From the above analyses, a design mission, summarized below, was created

    to accommodate these desired mission goals.

    - 1219 Passengers + 4 Crew

    - Cruise Altitude > 40,000 ft

    - Cruise Speed 0.85 Mach

    - Range of 7,100 nmi

    - Takeoff range 4,7005,000 ft

    - Landing Distance 2,5003,000 ft

    A high operating ceiling has many benefits. By choosing a cruise altitude of greater

    than 40,000 feet, our business jet will operate above the majority of air traffic allowing for

    higher speeds and a cruise-climb method, increasing altitude as the aircraft becomes lighter

    from burning fuel. This method improves the overall efficiency of the engines and decreases

    fuel usage.

    Timely flights are a desirable characteristic that consumers desire in a business jet. High

    cruise speed directly correlates to the flight duration. Therefore, the cruise speed of 0.85 Mach

    was chosen primarily from historical data and would offer a high speed while maintaining fuel

    efficiency.

    A range of 7,100 nmi, a conservative distance from Los Angeles to Hong Kong, China

    with a 50 kts headwind, was chosen as the design mission range for our aircraft. Destination

    flexibility is also important for a desirable business jet solution. With a takeoff field length of

    4,7005,200 feet and a landing field length of 2,5003,000 feet, our aircraft will have access

    to many small airports, bypassing many of the larger and more congested terminals.

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    MISSION SKETCH

    A mission profile is needed for determining the necessary capabilities of an aircraft

    design. This mission sketch is broken into several segments and outlines the important

    procedures that our aircraft might encounter during a normal missions operation. A basic

    mission profile is shown below asFigure 7. The steps of the mission are described in detail

    belowFigure 7.

    Figure 7 : Basic Mission Profile

    01: Taxi

    12: Takeoff

    23: Climb to > 40,000 feet34: Cruise at 0.85 Mach

    45: Descent

    56: Loiter (45 minutes)

    67: Approach

    78: Land

    67: Missed Approach

    7 9: Secondary Climb to > 40,000 feet

    910: Divert

    1011: Descent

    1112: Loiter (30 minutes)1213: Approach

    1314: Land at Secondary Airport

    Initially, the aircraft taxis onto the runway once filled with its payload. Takeoff involves

    the aircraftsacceleration to initial climb speed. This value will be determined after further

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    sizing and design. The next segment, shown as 23, is the aircrafts climb to cruise altitude.

    The climb to above the design missions 40,000 feet will be performed at the maximum climb

    rate available. After the cruise altitude is reached, the aircraft will cruise at 0.85 Mach for the

    duration of the primary mission. The high operation ceiling allows the business jet to cruise as

    a cruise-climb. From this point, the majority of the travel time consists of sustaining the cruise

    speed. When the aircraft nears the airspace of the destination airport, the aircraft will descend

    into the holding pattern. This descent is represented with a no-range credit. The loiter period

    at the primary airport is represented as segment 56. To ensure that the aircraft maintains

    fuel reserves to complete this procedure, a 45 minute buffer is designed into the fuel weight.

    Descent from loiter to the landing pattern, is the approach. As with the descent from cruise

    altitude, the approach is shown with no-range credit. The final step of the primary mission is

    the landing and taxi to terminal.

    Due to weather, a busy airport, or any other externality capable of preventing an

    aircrafts landing, an aircraft may be forced to divert to a secondary airport. The reserve

    mission from 614 represents the contingency plan in case of an inability to land. It is included

    in the mission sketch to ensure that adequate fuel is stored for a diversion. Segment 67

    represents the missed approach. Similar to the primary climb, the secondary climb is performed

    at maximum climb rate to cruise altitude. The FAA requires that an aircraft is capable of a 200nmi divert in the event of a missed approach. The aircraft will travel to the closest available

    airport while maintaining cruise-climb to the secondary airspace. Following the diversion, a no-

    range credit descent is performed to loiter. As part of the FAAs missed approach contingency

    requirement, an aircraft design must be capable of a 30 minute loiter in the secondary airspace.

    After the required loiter duration, segment 1213 represents the no-range credit approach to

    the secondary landing pattern. The final segment of the mission is the land at the secondary

    airport.

    TYPICAL OPERATING MISSION

    It is not reasonable to expect the designed jet to be required to operate at the full

    design mission at all times. Therefore, the decision was to have a typical operating mission of

    carrying 68 passengers, with 3 crew, over approximately 2,500 nmi. This mission allows for

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    many of the trans-continental destination pairs previously mentioned to be utilized. Though

    this typical mission does not fully utilize this designs capabilities, the airport flexibility of the

    design will allow for many shorter range flight opportunities. The versatility for trans-

    continental and trans-Pacific flights will be highly desirable for corporate and private operations

    and increase our market share.

    SYSTEM DESIGN REQUIREMENTS

    From the definition of the target customer, the assumptions concerning desired

    characteristics for the business jet were categorized by performance, aesthetics, service, and

    extraneous attributes. After evaluating these characteristics, it was found that range, speed,

    and comfort are of highest priority, followed shortly by destination flexibility and

    environmental image. While range, speed, and comfort are regularly desired qualities for a

    trans-Pacific personal business jet, destination flexibility and environmental image are

    developing concerns. In countries and locations where smaller airports are constructed, the

    ability for a business jet to avoid landing at the busier airports gives the customer the ability to

    make deadlines without worry of external factors preventing prompt landings. To address

    these factors, a variety of performance characteristics were selected. The house of quality is a

    graphic tool that defines a relationship between customer desires and the business jets

    capabilities. From its results, we prioritized range velocity and fuel weight.

    Comparing the designed jet to the current competitors, the range,price and speed are

    comparable, as seen in the House of Quality that is located in Appendix B. However, it is

    forecasted that a desire for technology less harmful to the environment will progress in the

    future. As such, the specific attempts to adhere to the NASA Subsonic Fixed Wing Project N+2

    goals will place the designed jet well ahead of current competitors in the categories of noise

    pollution, nitrous oxide emissions, and recyclable materials. Currently, the designed jet is

    targeting the 42 decibel sound reduction based on engine choice and engine location. For

    greater fuel efficiency, the choice of engine also provides approximately 15% improved fuel

    efficiency, which coupled with other design choices, is estimated to match the 40% fuel

    efficiency desired by the N+2 goals. While it is assumed that other competitors will attempt to

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    improve during this time. If the N+2 goals are met along with the previously mentioned

    conveniences of destination flexibility and high speed, it is assumed that the jet will have a

    stable place in the market.

    In the creation of the compliance matrix,Table 8,threshold values were taken from

    historical data or perceptions on the customer desires. Because of the desire to create a long

    range vehicle, the threshold range was set so that the aircraft could fly from Los Angeles to

    Tokyo. The target value was determined to be longer in order to bypass landing in Japan, and

    land directly in airports in China. Volume and height are based on cabin layout, and may

    increase dramatically based on the choice of aircraft configuration. The payload is currently

    based on the typical mission, and the speed is based on the engine choice. The values in the

    asterisks are currently historical estimates, and further calculations are necessary in order to

    determine the accuracy of these values.

    Table 8: Compliance Matrix

    Current Target Threshold

    APU Capacity [kVA] 110* 140 110

    Cabin Height [in] 70 77 72

    Cabin Volume [ft^3] 2000 2200 2000

    Cruise Speed [Mach] 0.85 0.9 0.84

    Cumulative Certification Noise Level[dB] 230* 130 150

    Empty Weight [lb] 52100 45000 55000

    Fuel Weight [lb] 34400 25000 45000Interior Decibel Level [dB] 70* 40 50

    Life [yr] 20* 30 20

    Maintenance hours/Service Hours 700 7000 7000

    Payload [lb] 2800 7000 6000

    Range - Still-air [nmi] 7100 7100 4500

    Recyclable Material % 25* 65 25

    Sill Height [ft] 5* 5 6

    Take off Distance

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    range business jet. Todays aircraft have already been extensively optimized and further

    improvements necessitate either a major technological breakthrough or a shift in design

    philosophy. Technological breakthroughs have drastic effects but are slow to implement

    because of required research and development before implementation. Therefore, a large shift

    in design methodology while still using what are essentially current technologies would be the

    best candidate to effectively meet N+2 and FAR regulations. This shift could include

    implementing different propulsion methods or aircraft geometry while using current materials

    and processes.

    In the 1980s,General Electric and NASAs Lewis Research Center studied a concept

    called an Unducted Fan (UDF). This concept was developed in response to rising fuel costs at

    the time. It initially began as a study to increase the efficiency of a geared turbofan engine. The

    higher bypass ratios corresponded to higher engine fuel efficiency. However, the weight and

    size of the gearing caused operating costs to increase as the diameter of the fan increased.

    Aircraft manufacturers also pressured the researchers to decrease the diameter of the engine.

    The increased fan speed made it possible to eliminate the gearing linkages between the power

    plant and the propulsion fans. Reducing the overall complexity of the engine and weight by

    also eliminating the necessary cooling equipment associated with a mechanical gearbox. The

    resulting test model consisted of a turbojet engine linked to a pair of highly swept, thin, contra-rotating fans. The dual fan arrangement allowed the engine to recover some of the air flows

    angular momentum generated by the first fan with the second. Shown below is the basic setup

    of this engine type.

    Figure 8: The original UDF concept demonstrator(NASA, 2009).

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    Figure 9: The original UDF concept demonstrator (Nichols, 1988)

    The UDF is lighter than a comparable ducted turbofan because of the lack of the outer

    cowling. This also causes a reduction in drag penalty. Greater airflow is achievable using the

    dual fans which nets greater fuel efficiency. The project demonstrated an uninstalled SFC of

    0.24 lbm/hr/lbf during the ground testing phase of the project. The high blade count allows for

    most vibration to be eliminated or reduced below acceptable levels. Additional measures are

    taken to damp out vibration caused by the turbojet power plant as well (NASA, 2009). The

    highly swept and thin blades allow for flutter free operation of the fans up to Mach .9. During

    flight tests, the UDF engine performed well within FAR noise regulations for both external and

    internal noise. The worst seat cabin noise level was 82 dB(Reid, 1988). Fan noise was largely

    controlled by blade spacing and tip speed rather than through the addition of heavy acoustic

    insulation to the aircraft. Still, the rotating fan blades could cause potential acoustic fatigue.

    Acoustic treatment would be necessary to shield the structural components (NASA, 2009). The

    study expected further improvements in noise abatement through quieter fan blades and

    designing improvements in vibration transmission from the power plant to the cabin (NASA,

    2009). Unfortunately, the project was dropped in the late 80s when fuel prices declined and

    the potential remained undeveloped. All the initial work was done in making this a viable

    technology to be implemented in the 90s.

    Unfortunately, no production model yet exists for data analysis. Given that this

    technology was pioneered in the 1980s, one expects that by using modern technology and

    tools, a new model now would surpass this initial design. It is difficult to validate that claim

    because the majority of the specifications of the engine were withheld from the AIAA papers.

    Specifically, the high altitude performance of the UDF is largely unknown; only 4 AIAA papers

    could be found on the subject at the time during this research. The papers listed a max

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    operation height during flight test of 35000 feet MSL at Mach .86 (Reid, 1988). This was the last

    height that they took measurements at and it is unclear if this is the actual operating ceiling of

    the engine. Literature dealing with engine structural failure, such as a fan blade breaking off in

    flight, was not published either. The exterior of fuselage in the affected zone around the fans

    would have to be protected from possible catastrophic blade failure. Further research is

    necessary before proceeding with UDF engine usage on the business jet.

    Drag reduction is accomplished in a number of different ways. Reduction of the overall

    wetted area of the aircraft reduces the parasite drag of the aircraft. Conventional wing and

    fuselage aircraft have a large amount of non-lifting wetted surface area. This is due to the

    surface area of the fuselage itself, which is typically constrained by the desired payload of the

    aircraft. There are also large stress concentrations where the wings attach to the fuselage. One

    approach to reduce both the drag and the stress is to use a hybrid structure in which the wings

    and the fuselage are smoothly joined. This results in a concept known as a Blended-Wing-Body

    (BWB) airframe. A BWB design allows for a reduced wetted area compared to a conventional

    design of similar capabilities. There is more lateral space in the fuselage allowing for increased

    seating and fuel storage. The airframe is also more evenly loaded than a traditional wing and

    tube design. This is known as span loading and an illustration of this concept is shown below.

    Figure 10: Comparison of Conventional and BWB loading (Liebeck, 2004)

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    Distributing the load of the aircraft smoothly across the span of the aircraft decreases

    the size of the structural components of the airframe, thereby making the plane lighter. There

    is much less interference drag between the fuselage and the wing which also makes the aircraft

    quieter because the airflow is smoother. A BWB aircraft is a strong candidate for meeting

    NASAs N+2 goals.

    All of these benefits come with a drawback potentially making the BWB concept

    unviable for a business jet. The first concern is that the cabin of the aircraft needs to be

    pressurized when flying at the cruise altitude. A large wide cabin, such as the one in a BWB,

    would be difficult to pressurize and would add weight to the aircraft. Structural supports may

    be necessary in the cabin itself to hold the top and bottom surfaces together (Cho, Bil, &

    Bayandor, 2008). This may prove problematic because that would detract from a spacious cabin

    which could be a potential selling point. Secondly, business jet passengers and owners typically

    view window number and size as important selling points. A BWB aircraft places the wings

    where windows are to be placed. One solution to this issue is to have screens in the cabin to

    act as surrogate windows so that the passengers could still view the exterior of the plane.

    Another option would be to place transparent or translucent panels on the top of the cabin

    section of the plane to act as skylights. These would not allow the passengers to see much but

    would at least let in some natural light. Lastly, BWB designs need to maintain a reasonablethickness to chord ratio, which may be difficult to match. To accommodate a six to seven foot

    cabin height would require at least a 70 to 80 foot chord on the fuselage airfoil shape. It may be

    difficult to accommodate the necessary cabin volume and still have less wetted area than a

    conventional aircraft. Stability and emergency egress could also prove to be problematic with a

    BWB business jet. Once again, further trade studies will need to be conducted to see if these

    obstacles can be successfully overcome.

    In addition to the BWB and unducted turbofans, other technologies are presently beingconsidered. These include alternate wing geometries and wing tip treatments such as winglets.

    Some alternate wing geometries under consideration are a tandem wing design and a joined

    wing. The joined wing design consists of two wings that are swept in such a way as to have co

    located wingtips. This could include a swept back wing joined to a straight or swept forward

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    wing. This geometry is reminiscent of biplanes except that the wings are not on top of each

    other. Winglets are used to decrease induced drag caused by the wingtip vortices present on all

    aircraft. They can be upright, slanted, endplates, or even manufactured in such a way that they

    double back into themselves, known as a spiroid. The joined wing and the winglets are intended

    to reduce drag but it is unsure whether or not the gains will merit the additional cost of

    manufacturing them.

    All of the technologies mentioned above require further investigation before they can

    be used on this design. Among other things the unducted fan needs to be proven at the cruise

    altitude of the aircraft and further research is needed into its compliance with current

    regulations. The blended wing body design needs to be thoroughly researched and proven to

    be feasible for a business jet sized plane. Trade studies will need to be conducted to

    demonstrate the feasibility of all of the technologies. A determination will be made to see

    which provide a sufficient benefit to merit the research and development costs necessary to

    implement them on this business jet design.

    CABIN LAYOUTS

    There are certain design constraints to which we must adhere to while beginning to

    design the jet. The cabin layout is one of these major constraints. The basis of the design

    philosophy was to start from the inside and design outward; this was done to ensure that there

    was sufficient floor space and volume to accommodate the passengers and all of their

    amenities. Passenger comfort is one of the main selling points for a business jet, and as such,

    the designs shown below were meant to maximize this. Further refinement and detail will be

    added later as more specific dimensions are determined.

    Figure 11: Floor plan for a conventional wing and tube aircraft.

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    Figure 12: Secondary floor plan for the conventional jet.

    The above two layouts are for a conventional wing and tube aircraft design, seating 16

    and 12 respectively. Both layouts occupy the same amount of space, thereby allowing for a

    standard fuselage design. The aerodynamics and structural aspects would remain the same.

    This will reduce the amount of additional tooling and equipment needed for different

    variations. Windows are not marked out inFigure 11 orFigure 12,but would be placed evenlydown the length of the cabin approximately adjacent to the bucket seats. Both layouts offer a

    galley, dual restrooms, crew rest for a reserve pilot, and additional storage spaces denoted as

    cabinets. The crew rest is in place for trans-Oceanic flights in which the flight time exceeds

    the work day of a single pilot. The cockpit, though not specifically shown in either design, would

    be a typical layout seen in most business jets. The tail section (to the right of the figures)

    would be largely empty, possibly housing a baggage compartment. Emergency exits would be

    located on the starboard side of the plane and out the aft pressure bulkhead of the cabin.The cabinets and galley will provide ample storage for food, beverages, blankets,

    pillows, and other desired commodities. The single seats in the cabin will have the ability to

    swivel, which would facilitate conferencing and other tasks. The red rectangles and ellipses

    denote tables which can be stored inside the side walls when not in use. This will allow for

    increased personal space during other activities when desk space is not needed. To the rear of

    the passenger cabin is a pair of joined seats. These are intended to be used for high capacity

    flights to fit the last two passengers at the cost of some personal space. Overall, the designs arefairly typical of business jets in this class of operations.

    The design of the cabin space in a blended wing concept varies greatly, thus, additional

    layouts were created. A BWB offers a large amount of additional lateral volume that could be

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    utilized as cabin space. Shown below, inFigure 13,is a silhouette of a BWB with an approximate

    cabin layout superimposed onto it.

    Figure 13: BWB silhouette with cabin layout.

    A BWB design offers one and a half to two times the cabin width as compared to a

    conventional design. The same features are available with the BWB concept as the conventional

    layout. One of the main benefits of the concept is that it offers two aisles and increased volume

    per passenger as compared to a conventional wing and tube design. Twin doors are present for

    entry and exit. Additional emergency exits could be positioned to the aft of the cabin area or

    out across the wing. These would be dependent on later design considerations. In both BWB

    layouts the forward restroom is positioned essentially in the cockpit. This was done based on

    the thought that crew quarters could be separated from the passengers more than usual. This is

    not particularly uncommon in some of the larger business jets on the market today. Shown

    below are the two conceptual layouts for the blended wing body.

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    Figure 14: Parallel side BWB cabin layout concept.

    This first layout consists of a cabin with twin aisles and seating for 19 passengers. There

    are some possible FAR regulations limiting the number of passengers in this size business jet, so

    this number may be reduced accordingly. As stated before, this design offers similar

    accommodations as the conventional design, but with more personal space. No tables are

    shown in this design at the current time, but will be added in later designs. The tables would

    likely swing up from the sides of the chairs, similar to a student desk in a lecture hall. This

    design also features a locker which would offer additional storage.

    Figure 15: Flared aft BWB cabin layout concept.

    Most blended wing concepts have a large amount of internal volume, especially towards

    the back of the aircraft. This second layout concept features a flared aft section in order to

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    utilize this additional space efficiently. This flared back allows for a theater-style seating

    arrangement. A screen could be installed just to the aft of the cockpit bulkhead to allow an in-

    flight movie or meeting presentation. Once again, the tables can be stored in the side wall to

    allow for more space. A full galley and storage areas are once again employed to house all of

    the amenities.

    There are some issues that will need to be resolved later in the design process. Among

    these issues would be the cabin height. It is likely that the cabin will slope down from the

    middle somewhat towards the sides. This should not be a major concern because the aisles will

    still have a full standing height. Probably the biggest concern about a BWB concept is its

    inherent lack of windows in the passenger cabin. The wings are typically mounted along the

    area where the windows would be placed. This could be a large problem if an acceptable

    alternative is not available. As mentioned earlier, transparent panels or screens that act as

    surrogate windows could be used to counteract the lack of windows. Obviously there are some

    design considerations that must be accounted for before finalizing a design. It may turn out that

    the blended wing concept is not viable for a business jet sized aircraft. Until that decision is

    made, it is still wise to keep all options in mind.

    SIZING ESTIMATES

    With the aircraft requirements and design missions largely laid out, a basic sizing

    analysis of the aircraft was undertaken. The entire design method contains many iterative

    methods, sizing being one such instance. By having a general idea of the weight of the aircraft,

    design variables such as thrust and wing geometry can be approximated. Refinement of these

    variables will lead to changes in the aircraft weight. However, this initial step is required in

    order to begin making design choices.

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    Figure 16: Constraint Diagram

    A constraint diagram was generated to determine which segments of flights are the

    most crucial in sizing the business jet. This diagram was generated by choosing our service

    ceiling, cruise Mach number, and aspect ratio. As seen inFigure 16,our business jet was

    constrained by the Second Segment Climb and Takeoff Ground Roll for high and hot days, which

    were developed by our initial sizing estimates. Our ideal flight envelope would have a Thrust to

    Weight ratio above 0.344 with Wing Loading at approximately 80 lb/ft2. However, due to

    further research, it was found that our business jet will be constrained by the Top of Climb

    instead of the Second Segment Climb. With these initial estimates for our jet, we developed a

    sizing algorithm.

    A MATLAB subroutine was assembled in order to provide weight estimates for the

    aircraft. The algorithm used was a first order design method outlined in Aircraft Design: A

    Conceptual Approach Fourth Edition. The method involves estimating empty weight and fuel

    weight fractions of the aircraft and iterating until an appropriate value is reached. The following

    simple flowchart gives a general outline of the algorithm:

    0

    0.2

    0.4

    0.6

    0.8

    1

    40 50 60 70 80 90 100 110 120

    TSL/W0

    W0/S [lb/ft2]

    Top of Climb (1g Steady,Level Flight, M = 0.85 @h=40K, Service Ceiling)

    Subsonic 2.5g Manuever,250kts @ h =10K

    Takeoff Groun d Roll 3,500 f t@ h = 5K, +15 Hot Day

    Landing Ground Roll 2,500 ft@ h = 5K, +15 Hot Day

    Second Segment Climb

    Gradient Above h = 5K, +15Hot Day

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    Figure 17: Code Flowchart

    W0is takeoff gross weight, Weis the empty weight of the aircraft, and Wfis the fuel

    weight of the aircraft. The empty weight fraction was determined from a database of aircraft

    flying today. The database, shown in Appendix A, tabulated characteristics such as takeoff

    gross weight, aspect ratio, wing area, etc. The only aircraft considered were those with similar

    design mission:

    Table 9: Aircraft Database

    Manufacturer Model Range Passengers

    Bombardier Global 5000 5200 17

    Global Express 7077 19

    Gulfstream G500 5800 19

    G550 6750 19

    G650 7000 18

    Dassault Falcon 7X 5950 19

    Falcon 900B 4800 14

    With this database, a least squares regression was created in order to generate an

    empty weight fraction approximation. The regression took into account takeoff gross weight,

    aspect ratio, thrust to weight at sea level, and maximum Mach the aircraft is capable of. The

    following was the form of the equation used in the final calculations:

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    (Eqn. 1)

    The takeoff gross weight was an arbitrary value chosen to start the sizing iteration

    process. The aspect ratio chosen was 7.5 with comparison to aircraft in the database. The

    thrust to weight value used in the sizing iteration was 0.34 which derived from both the

    historical database as well as the constraint diagram. The maximum Mach used in the analysis

    was determined from research of unducted turbofans. A detailed discussion of unducted

    turbofan technology is outlined in the advanced topics section. Early research by General

    Electric shows that the design is capable of efficient speeds up to Mach 0.9. However, this

    decision was made before considering the high cruise altitudes effects on the propfans

    capabilities. The propulsion choice will have to be re-evaluated; however, the maximum Mach

    is likely to remain in a similar range as other aircraft in the long-range category. In observing

    trends of business aircraft, the consumer desires vehicles capable of offering speeds greater

    than other civilian aircraft.

    The fuel weight fraction was calculated by a combination of historical estimates as well

    as using the Breguet range equation:

    (Eqn. 2)

    In the previous equation, the variable Ris range, uis aircraft velocity, cis specific fuel

    consumption, and L/Dis lift to drag ratio. The equation was rewritten in terms of the weight

    fraction within the natural logarithm to form the following:

    (Eqn. 3)

    The equation was also modified for loiter by replacing the range term by loiter time as

    well as removing the aircraft velocity term. With these equations, the fuel weight breakdown

    was done as follows:

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    Table 10: Fuel Weight Fraction Estimates

    Mission Segment Constants

    Takeoff (0-1) 0.97

    Climb (1-2) 0.997-0.007Mcruise-0.01Mcruise

    Cruise(2-3) Eqn 2

    Descent no range credit (3-4) 0.995Missed approach (4-5) 0.97

    Climb (5-6) 0.997-0.007Mcruise-0.01Mcruise

    Cruise to alternate (6-7) Eqn 2

    Loiter (7-8) Eqn 3

    Descent no range credit (8-9) 0.995

    An additional 1% was added to the fraction in order to account for trapped fuel. The

    design variables used in the Breguet range equation would play significant roles in the final

    weight estimate of the aircraft, as the cruise segments would consume the majority of the fuel.The range used for the weight estimate was 6,700 nautical miles with 200 nautical miles being

    the distance to the alternate airport. A loiter time of 0.75 hours was chosen for the design. The

    previous values for range and loiter were determined by NBAA fuel reserve requirements. A

    cruise Mach of 0.85 was chosen in order to conserve fuel, but the justification behind this value

    is fairly weak without more detailed data about the propulsion system and aircraft geometry.

    Two factors with large impacts on the fuel weight were specific fuel consumption (SFC)

    and maximum lift to drag ratio. The SFC estimate was made using the following figure:

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    Figure 18: SFC trends in the past 60 years (Zelina & Ballal, 2004)

    The above figure estimates fairly low SFC for our initial operating period. If the trend

    line is liberally extrapolated, it is observed that a SFC of 0.25 is possible by 2020. This was not

    the value selected for several reasons. Primarily the most efficient engines are high bypass

    turbofans with very large diameters such as Rolls Royces Trent 1000 and General Electrics

    GENx. These engines were deemed too large to use for the aircraft. Secondly, these values are

    most likely uninstalled SFC that do not account for inefficiencies due to nacelles and power

    required by aircraft systems. Since this is a forecast the SFC value used for cruise was 0.35 lb/hr

    and 0.4 lb/hr for loiter. Further research will be required since these values are considered very

    optimistic.

    The maximum lift to drag ratio was estimated using an empirical formula found from

    Fundamentals of Aircraft Design, which states:

    (Eqn. 4)

    An aspect ratio of 7.5, as specified earlier, produces a maximum lift to drag value of

    17.6. This value was compared to other aircraft to confirm the magnitude. A L/D of 18 was

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    found for Boeings 747 while the Gulfstream G550 was reported to have a L/D of14.7 at Mach

    0.854 and 18.68 at Mach 0.7. The cruise L/D ratio was approximated to be 0.87 of the

    maximum L/D, as mentioned during a lecture by Dr. Crossley. The lift over drag value used for

    the missions loiter phase was assumed to be the maximum lift to drag ratio. The values used in

    the analysis were typical of aircraft with similar size.

    Equation 5 was used in order to estimate the takeoff gross weight as a function of both

    empty weight and fuel fractions.

    (Eqn. 5)

    As mentioned previously, a crew of 4 and 19 passengers was used for the payload

    weights. Each person was allotted 225 pounds which takes into account for their luggage. The

    previous estimate of 200 pounds used for passenger weight was deemed too low by

    Gulfstreams design team.

    Technology factors were considered for the sizing estimates; however none were

    implemented for the lack of data to correctly assess their impact.

    - Alternate wing geometries and composite materials have the ability to lower the empty

    weight of the aircraft.

    - Improved gas turbine engines can lower specific fuel consumption, reduce emissions,

    and reduce noise. The first point will contribute to fuel weight required.

    - Alternative fuels have shown promise in lower emissions of gas turbine engines in

    recent studies; however, these should not have much of an effect on aircraft weight.

    In approaching the desired trade studies, algorithms were created to perform initial

    calculations. Preliminary results for a standard tube-and-wing configuration are as follows:

    Table 11: Initial sizing results

    Parameter ValueTakeoff Gross Weight 90,300 lb

    Empty Weight 52,100 lb

    Fuel Weight 34,400 lb

    Empty Weight Fraction 0.57

    Fuel Weight Fraction 0.38

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    SUMMARY AND NEXT STEPS

    Considering the aforementioned topics, an opportunity for a new business jet to capture

    a portion of the market and proactively prepare for the eventual changes as the new decade

    begins. Market analysis has shown that the demand for this type of business jet will continue to

    grow. As the concerns of executives and business employees increase, a timely and efficient

    form of travel will increase in demand. Along with heightened awareness and concern for the

    global environment, todays business jet features will continue to persist. To meet this need,

    initial requirements have been established based on current aircraft designs. Now that the

    benchmark figures and goals have been concisely described, further trade-offs must be

    investigated in order to increase the marketability of our aircraft.

    Since the steps for preliminary design have been completed, our team will begin the

    conceptual design phase. The first step for conceptual design is to complete a more

    comprehensive trade study of the technologies available. The trade studies will be researched

    based on the ideas conceptualized from a brainstorming session along with an iterated process

    for design selection. After the selection process for the design is completed, an updated version

    of the sizing code will be created. This version of the code will implement the chosen design

    characteristics from the brainstorming session as well as updated sizing equations and

    technology factors from the trade studies.

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    WORKS CITED

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    APPENDIX A: AIRPLANE DATABASE

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    APPENDIX B: HOUSE OF QUALITY