Table of contents

INTRODUCTION

Mission statement

Outline

MARKET AND CUSTOMERS

Projected Business Market

Cabin Model

Mission Sketch

Design Mission

Operating Mission

SYSTEM DESIGN REQUIREMENTS

The House of Quality

Compliance Matrix

Benchmark Aircrafts and New Technology

INITIAL SIZING ESTIMATES

Database

Constraint Diagram

Initial Estimates

Summary

Next Steps

REFERENCES

APPENDIX A

INTRODUCTION

The past decade has seen a considerable amount of economic advancement take place in the international markets, where countries such as China and India have become industrial leaders. Due to such rapid growth,many fortune 500 companies seek to take advantage of this situation by expanding their businesses in these countries. Keeping this in mind, designing a long range aircraft with time saving capabilities is promising.

The team will target multinational corporations as their main clients, for whom time is money. Providing an aircraft which will save clients time and help increase revenue is a crucial design objective. The proposed aircraft will also be designed to meet and exceed all of the environmental N+2 standards set forth by NASA.

Research, use of historical data, and other tools such as computational packages, are being used to design the aircraft. The team has taken into consideration every customer requirement and has developed an aircraft catered to meet these requirements. The goal of the project is to design an aircraft that gives its customer a truly elite ownership experience.

Mission statement

The main goal of this project is to design a cost effective aircraft with high speed capabilities, which is able to transport its customers to their desired locations in the least amount of time possible. The project’s secondary goal is to meet NASA’s N+2 criteria, reducing the environmental impact of the aircraft. The proposed aircraft will be able to compete with other aircraft in the ultra long range category.

Outline

This report is comprised of five sections. The first section will give the reader a brief market overview discussing customer needs and benefits. It will also discuss current market sizes and address competitor’s aircraft. The next section is the concept of operations section, also referred to as the CONOPS. In this part of the paper, the team will address crucial components of the project’s goals such as customer satisfaction and its affect its influence on the aircraft. The CONOPS section will also cover expected flight ranges and required runway lengths, the aircraft’s payload and passenger capability, mission sketches, and segment descriptions.

The system design requirements section follows the CONOPS section,and contains the house of quality in detail. It also explains how the team intends on meeting NASA’s N+2 goals,and introduces new technologies that might be integrated to assist the design in meeting these goals.

Following system design requirements, initial sizing estimations will be computed. These estimates contain values such as; lift to drag ratios, Specific Fuel Consumption (SFC),and empty weight fractions. The final section discusses the projects future design goals. This includes the future steps which will need to be taken in order to accomplish the objective of the project.

MARKET AND CUSTOMERS

Primary customers

Prior to starting the design process, a market analysis study was conducted to find the ideal market niche to accommodate. Identifying the primary client was the first step. In the past 2 years there has been a substantial plummet in the financial market. The only groups of people that have not changed their outlook as a result of this downfall are the wealthier side of society, including CEO’s of multinational corporations and celebrities. This elite class of passenger prefers a luxurious, fast, and private travel experience. Using a public airport is usually a very inconvenient and time consuming endeavor. Historically this side of society has a proven financial stability track record and was deemed to be the primary customer. With this historically stable clientele, the outlook for expected aircraft sales in this class has remained and is expect to stay stable and maintain steady growth. Other possible clientele include fractional air services.

Projected Business Market

According to the Research firm Frost & Sullivan, the Middle East and Asia are one of the few world regions where the long haul business jet market has registered growth. The air-taxi segment is also expected to be a major driver for this market. According to the Frost & Sullivan’s data, the Middle East logged 93,000 business jet movements in 2008, this number was projected to reach 103,000 last year. Growth is expected to continue, reaching 160,000 jets in 2018. Frost & Sullivan projected the compound annual growth rate of business jet movements in the Middle East will be about 6.21 percent from 2008 to 2018. Figure 1 depicts markets in various regions of the world.1

Figure 1: Business Aircraft Expansion Percentage.

As the economy recovers from the current downturn, orders for business aircraft are expected to increase, which should sustain salesfor new business jets over the next10 years. The sharp contraction of the U.S. economy and ensuing worldwide recession during 2008-2009 is expected to cause a significant reduction in the near term demand for business jets. Many original equipment manufacturers (OEMs) have and will likely continue to receiveorder cancelations in early 2009 . Order intake is forecast to fall as low as 375 units in 2009, and is expected to improve by the end of the year, reaching 2008 levels of approximately 1,400 units per year by 2013.2

Figure 2: Purchase Plan Analysis.

Figure 2 depicts a pie chart which breaks down intended purchases by aircraft type. The chart clearly shows that the bulk of jets to be purchased are of the large cabin class. The following pages discuss the technical details of our design, which is believed to offer the best possible solution for the customers.2

Cabin Model

The aircraft was conceived as a 16-passenger business class jet. Accordingly, the initial sizing of the aircraft was directly dependent on an efficient and attractive layout capable of comfortably seating 16 passengers. Design began by choosing the general shape of the cabin, and a cylindrically-shaped cabin was found to be of the greatest benefit due to its association with reduced manufacturing costs. Additionally, this design would simplify the pressurization of the cabin.

Once the shape of the cabin was determined, the next step was to scale the aircraft. The two major dimensions requiring attention in the sizing of the cabin were its length and interior diameter. The aircraft that is most similar (currently in certification testing) is the Gulftsream G650. Therefore, when determining the cabin’s diameter (and length), figures were checked against Gulfstream’s to ensure an additional level of realism. Numerous layouts were considered before settling on one which offers the client a wide variety of seating arraignments and ample personal space. The cabin currently accommodates seating for up to 16 passengers and a resting area for 2 crew members. The cabin is furnished with 2 sofas, 6 individual seats, and conference seating for 4. It is also equipped with a large galley and two lavatories, one at the front of the cabin and one positioned aft of the main cabin where the tail meets the fuselage. The main entrance and exit is positioned between the forward lavatory and the nose of the aircraft. Even with all of the aforementioned amenities, the cabin still boasts a personal volume of 81.5 cubic feet. Note that this volume is calculated for a full cabin of 16 passengers, which means that any flights carrying fewer than 16 passengers (which is expected to be quite often) will allow for even more personal space. The graph in Figure 3shows a correlation between trip duration and cabin space. This graph was provided from Torenbeek, synthesis of subsonic aircraft design. From this graph, it is possible to see that with a volume of 81.5 cubic feet per passenger, our aircraft will allow 16 passengers to fly in “plush” comfort for up to a four hour trip. As the number of passengers decreases, each passenger will have more room and the amount of time for the “plush” category will be increased. The trend lines for this plot are linear, so it is also possible to continue them out to a max flight time of 12 hours. Even with a full cabin of 16 passengers, the aircraft boasts comfortable accommodations for a full length flight.3

Figure 3: Comfort vs. Duration.

However, this number is low in comparison to the G650, due to two main factors:the G650’s greater cabin length and elliptical cabin shape. This style of cross section has a flatter lower section to make better use of internal volume. Still, the team’s design is both attractive and efficient, and therefore its general shape will not be changed at this point. By affording accurate sizing and spacing to the cabin layout, an estimate of its initial length was found to be an even 50 feet. The cabin’s inner diameter was chosen after careful consideration of current similarly scaled business jets and the client’s needs.

The length of the nose and tail are usually sized according to a fineness ratio, calculated to be the ratio of the length of the section divided by the cabin diameter. Sizing began by investigating the range of fineness ratios currently in use and it was found that the nose of current aircraft usually have a fineness ratio between 1.5 and 2, while the tail of current aircraft usually have a fineness ratio of between 2.5 and 3. At this point in the design, no consideration for the aerodynamic impact from fineness ratio has been made; aside from staying within current ranges. It is however recognized that, particularly for a transonic aircraft, the fineness ratio of the aircraft plays a critical role in drag production. The nose and tail were designed with fineness ratios of 1.6 and 2.7, respectively, based upon visual cues from current high performance business jets. However, these lengths are by no means finalized and changes are anticipated further into the design process. Because the fineness ratio is a comparison of section length to cabin diameter, the resolution of these ratios also means that the first estimates for the lengths of the nose and tail. These estimates are 1.6*(8.83 feet) = 14.17 feet for the nose and 2.7*(8.83 feet) = 23.9 feet for the tail. This provided the first practical approximation of the aircraft’s total length at 88 feet.

The aircraft’s total fineness ratio was found by dividing the aircrafts total length by the cabin diameter. Currently the aircraft boasts a fineness ratio of 9.96. Comparing this to the G650’s ratio of 11.08, this aircraft’s fineness ratio is certainly well within realistic range.This is based on the fact that this aircraft is designed to compete with the G650 at its own transonic flight regime. Also, while the fineness ratio is not the ultimate choice when it comes to performance, it is a very important characteristic to consider and likely one whose impact will have to be weighed against other necessary performance characteristics in the future.Comparing the nose and tail to the main cabin visually, the chosen fineness ratio set the aircraft’s lines in terms of length ratios, visually depicted in Figure 4 below.

Figure 4: Effect of Overall Fineness Ratio on Aircraft Length.

Resulting from the interior sizing is an aircraft cross-section with two rows of outboard seating, and a center aisle from the fore end of the cabin until the conference area. Primary dimensions for the interior cross sectional area are shown in Figure 5, and a dimensioned top-view of the main cabin is provided in Figure 6, with a detailed drawing showing seating dimensions in Figure 7.

Figure 5: Interior Main Cabin Cross Section.

Figure 6: Top View of Interior Cabin Dimensions.

Figure 7: Detail of Cabin Amenity Dimensions.

While the specifications of the aforementioned cabin layout can provide passengers with a plush flight experience for a set duration, a cabin re-design is currently underway to further heighten passenger comfort. The incorporation of an industry-competitive quantity of windows placed in a manner to provide ample passenger view while retaining cabin flexibility is currently being incorporated in the cabin layout. A “designing from the cup holders”, comfort first, interior design mentality is shaping the next generation of cabin interior. The incorporation of minor amenities such as the very cup holders, individual ventilation outputs, the infringement of chair reclining on other passengers, aisle widths and personal privacy concerns are also under current refinement.

In addition to the chair and sofa design, passenger comfort was addressed in regards to lavatory size and placement. The rear lavatory’s location aft of the rear bulkhead provides a visual separation from the passengers in the main cabin, but maintains a close proximity to the conference area and galley. Emergency exit placement was chosen from both safety, as well as spatially contributing perspectives. The emergency exit was placed approximately mid-length in the cabin, and on the opposite outboard wall of the main cabin door. This location provided both an easily accessible location for exit from the conference and mid-cabin seating areas, and further ensured a wide aisle width through the conference seating, providing a spatial break from the non-conference seating. Location of the emergency exit and other key features of the aircraft interior are visible in Figure 8below.

Figure 8: Aircraft Interior Key Features

Focusing not only on passenger comfort, crew comfort on extended flights is currently under design refinement. While the two crew seats can be fully reclined, a crew rest area containing two stacked bunks is under development, though its isolation from the main cabin without infringement upon aisle width requires further assessment. The expanded crew rest will provide a bunk for an additional pilot and a current crew member during extended flights. Cabin adjustment with the incorporation of the crew rest area will necessitate a re-arrangement of interior cabin space, incorporating the currently unused space along the right outboard wall at the rear of the main cabin. A rendered image of the current cabin layout is provided in Figure 9 below for visual reference.

Figure 9: Rendered Image of Current Cabin Mockup

CONCEPT OF OPERTATIONS

Mission Sketch

It is understood that with businesses time is money so the need to move people quickly and efficiently to and from meetings is of utmost importance. In today’s economy, businesses are not necessarily tied down to one country but instead are spread across several locations around the world.This makes personal meetings substantially more difficult. Flying conventional commercial flights to and from meetings, while seemingly cheaper than taking a business jet, actually incurs larger costs due to the major losses in time. It is this dilemma of unnecessary and costly wasted time that this project looks to address. A key component of this aircraft is to provide a long range business jet that enables truly global transportation. With a still-air range of 6350 nautical miles, this aircraft is capable of making non-stop international flights; eliminating the costly layovers associated with commercial flights and shorter ranged business jets. As seen in the following table, the range of 6350 nautical miles puts several desirable destinations well within reach.

Table 1: Distances between City Pairs.

Los Angeles
to
Seoul / Dallas
to
Moscow / Los Angeles
to
Beijing / New York
to
Dubai / Chicago
to
Tokyo / Los Angeles
to
Hong Kong
5209 nm / 5035 nm / 5432 nm / 5949 nm / 5452 nm / 6309 nm

Design Mission

The design mission was developed and optimized with the city pair of Los Angeles and Hong Kong in mind. The design mission consists of eight mission legs between nine points as illustrated in the following figure.

Figure 11: Design Mission Flight Plan.

The first leg of the mission, from points 0 to 1, is taxi and takeoff to an altitude of 50 feet. From points 1 to 2 is the climb portion of the mission where the aircraft climbs at best rate to an altitude of 42,000 feet. From there the aircraft enters the cruise leg of the mission, between points 2 and 3, and begins cruising at a Mach number of 0.85 for 6350 nautical miles. Cruise is then followed directly by a no range credit descent to land where the aircraft will attempt a landing, from points 4 to 5, climb to an altitude of 5000 feet at best rate climb, points 5 to 6, and commence cruise to an alternate airport 200 nautical miles away. Once at the alternate airport, the aircraft will enter a holding pattern for 45 minutes, from points 7 to 8, and then begin a no range credit descent to land. Finally, the aircraft lands at the alternate airport and completes the last mission leg at point 9 when it comes to a stop.