The VicTor is a single engine, four seat, high performance aircraft with very unique features. These features include a sleek airframe, an ergonomic cockpit with adjustable side sticks and dual airbags, a choice between two very high performance engines, advanced technology instrument displays and an upgrade option to autonomous flight.

When you see The VicTor for the first time, the forward swept wings with slight dihedral and inverse cruciform tail immediately catch the eye. The layout is strikingly unconventional and whispers to the pilot, "Go ahead… Try me!"

Walking up and trying the door latch, you are immediately surprised by the quiet efficiency of the gas struts that effortlessly lift the gull wing door. Your attention is quickly transferred to the cockpit interior; bucket seats comfortably cradle the pilot and copilot, while the rear bench seat provides comfort for two adult passengers or three small children.

Before entering, the armrest is up and out of the way. When you climb into the seat and rotate the armrest down to the flying position, the side stick becomes apparent. It is mounted in the armrest and has full range of motion: up, down, telescopic movement fore and aft, and rotates to a position which is most comfortable for you, the pilot. You move the seat forward until you are in a comfortable flying position.

Once you adjust the seat, you notice the care that has been taken in the design and layout of the instrument panel. Directly in front of you are eight liquid crystal instruments that display flight information in a traditional gauge format. Just to your right lies a cathode ray tube similar to a computer screen but surrounded by menu buttons. These buttons are used to navigate interactively through flight plans with Global Positioning System based maps, communications information, and engine data.

From the cockpit, the two engine options are not apparent, however, both are very real and very powerful. You have chosen to fly the standard engine, the Zoche Aero-Diesel. This rotary diesel is light but strong—270 pounds, 300 horsepower. The optional engine is the developmental Williams Turboprop, lighter and stronger at 170 pounds and 450 horsepower.

When you close the door and start the engine the distinctive sound of the rotary diesel all but disappears as the cabin automatically pressurizes. You notice that the engine control is within easy reach for both pilot and copilot.

After you taxi to the end of the runway and secure final clearance, you increase the throttle and the extreme power of The VicTor kicks you in the pants! The VicTor accelerates down the runway and at the proper rotation speed you draw the side stick back with the least amount of force. The VicTor leaps off the runway in less than 560 feet. To test performance, The VicTor is set for maximum rate of climb of 3000 feet per minute. Throughout the flight you notice that the force feedback control stick and the fly-by-wire system are smooth and responsive.

When you reach the cruise altitude of 15,000 feet, you notice the airspeed indicator registering 186 knots. You recall from the preflight that The VicTor has a maximum range of 2,270 nautical miles and a maximum endurance of 20 hours.

As you bring The VicTor back to the airport and prepare for final approach, you extend the split flaps and notice the drooping of the ailerons. This combination of high lift devices allows the main wheels to touch down at 52 knots. After you finish the post flight check, backlit by a beautiful southwestern Virginia sunset, you realize that the general aviation market will be changed forever with the introduction of The VicTor. While it is currently unknown, it will not stay that way for long.

The above description is what you might experience in the new general aviation design from Virginia Tech. The VicTor will not only turn the general aviation industry around but also usher in 21^st century general aviation. It will provide the power, performance and comfort that today’s pilots crave and provide a link to the future’s "Highway in the Sky" flight environment with full autonomous flight.

Over the last fifteen years the general aviation market has steadily declined. Reaching its peak in 1978 when U.S. manufacturers delivered 18,000 new general aviation aircraft, in 1995 the production of new planes dropped 95% to 800 deliveries¹. Liability suits have been a major reason for this decline. These law suits cost the U.S. 20,000 manufacturing jobs and 80,000 support related jobs². Recognizing these tremendous losses, the U.S. Congress amended the Federal Aviation Act of 1958 by passing the General Aviation Revitalization Act of 1993. This act allows U.S. manufactures to again compete with foreign companies by reducing the liability risks associated with building general aviation aircraft².

The average age of a general aviation aircraft is 28 years and the technology in these aircraft is severely outdated, sometimes by as much as 40 years¹. Protected from excessive liability suits, the current goal is to convince U.S. manufactures to introduce new aircraft utilizing state of the art technologies. Through programs such as the AGATE General Aviation Design Competition, the FAA and NASA hope to stimulate breakthroughs in technology and the application of advanced technology into the general aviation market. Revitalization initiatives, such as this design competition, seek to increase the use of general aviation aircraft in the U.S., thus stimulating the general aviation economy. This revitalization will provide for newer, more efficient, safer aircraft¹.

The VicTor’s design was a true multidisciplinary, multilevel, international effort. The team consisted of Virginia Tech engineering students from numerous disciplines. Juniors and Seniors came from Aerospace, Electrical, Industrial, Materials and Mechanical Engineering majors. During the spring semester, the team also included first and second year engineering students. Throughout the design process, engineering students at Loughborough University, Loughborough, England, who were working on a similar design project, were consulted for ideas regarding the design.

The Virginia Tech team was divided into small, specialized, Integrated Product Teams (IPT). These teams looked at specific aspects of the design, including propulsion, aerodynamics, structures, performance, automated flight, ergonomics, and manufacturing. As the design was finalized, another IPT was organized for wind tunnel model construction.

By using concurrent engineering and the IPT approach, each member of the design team provided support in different areas of the aircraft’s design. The final design of The VicTor reflects the compromises and efforts of each member of the team, producing a high performance, comfortable aircraft that will usher in the 21^st century for general aviation.

Advanced General Aviation Transport Experiments Consortium, AGATE, provided the preliminary criteria for The VicTor’s design. These criteria specified that the aircraft must be single engine, propeller driven, carrying 2-6 passengers. It must have a range of at least 800 nautical miles and a cruise speed of at least 150 knots.

To meet these criteria, The VicTor was designed to carry 4 people with ample room for luggage. The overall performance was defined to exceed AGATE criteria because most current general aviation aircraft fall within these specifications. To exceed these performance parameters, advanced propulsion concepts were researched and integrated into the design. While the idea of autonomous flight seems unlikely in the immediate future, The VicTor was designed both to operate within today’s current environment and prepare for 21^st century autonomous flight. To reduce cost, advanced manufacturing techniques not currently in use in the general aviation industry were enlisted. To reduce weight and increase strength, advanced composites were incorporated into the design of The VicTor.

All of these ideas are united in the goal of the general aviation revitalization. The means to this goal is through a high performance, fun to fly, safe, affordable aircraft that are prepared to fly on the "Highway in the Sky" of the 21^st century. The layout of this design is given in the Figures below.

General


Inboard


Structural

The approach to design, like The VicTor itself, makes use of all available technologies. Traditional methods of design and analysis were used in combination with developmental computer programs in order to produce the final design. Due to the multidisciplinary nature of The VicTor design team, detailed analysis was permitted in a variety of areas, including those infrequently considered in academia.

There were several resources that were consulted by more than one IPT. A majority of the initial design conception came from comparative studies and historical data of the general aviation market. Additionally, the automotive industry was used as a marker of how a major transportation market develops successfully. Research into current fields of interest, such as electric propulsion, computer integration, and environmental impact was also conducted. Design and analysis methods developed by Jan Roskam³ and Daniel Raymer⁴ aided in initial design analysis and final refinement of several systems. Federal Aviation Regulation⁵ requirements were also referenced in all design aspects. Computer assisted drawings were designed using AutoCAD⁶, Ideas⁷, and HumanCad⁸.

Because of an initial desire to explore unique design approaches numerous alternative forms of propulsive energy were considered and shown to be currently inadequate for the design characteristics desired. A large comparative study of conventional propulsion systems was done, resulting in the selection of the Zoche Aero-Diesel⁹ as the primary system and the Williams Turboprop as the optional system. These propulsion systems were chosen through consideration of performance, economic, and environmental factors.

Suppression of noise within the cabin was first researched through actual flight tests of current general aviation aircraft. It was determined that the constant noise exceeded the levels recommended by OSHA. To eliminate much of the noise in The VicTor’s cabin, a balanced engine mounting and closed-cell acoustical foam insulation were used. To reduce propeller acoustical levels and maximize propulsive efficiencies, propeller studies were conducted with the help of the Hartzell Propeller company¹⁰.

Many different types of deicing systems were researched. Resistive heating and electro-expulsive methods were thought to be good choices for low drag considerations, however, these two technologies proved to be inadequate. Much information regarding conventional pneumatic boot de-icing systems was due to the help of the B.F. Goodrich Corporation¹¹. Due to the overwhelming design effort to minimize drag, the pneumatic system will only be offered as an option for extreme icing climates; the main de-icing technology will be that of an on-board weather avoidance system, such that the aircraft and the pilot may avoid encountering icing conditions.

Aerodynamic design and performance analyses were aided through the use of a variety of computer codes. Wing optimization calculations were performed using a lifting line theory based code called MONOPLN.BAS. Refinements were done using codes written in Mathematica¹² and Microsoft Excel¹³. Aerodynamic property and performance calculations were done with a vortex lattice method code, JKayVLM¹⁴. Flap effectiveness was calculated via the Weissinger Approximation. Natural Laminar Flow analysis was performed using the Laminar Airfoil Manager GUI for Design and Analysis written by Innovative Aerodynamic Technologies¹⁵. Additionally, a wind tunnel test model was constructed in order to verify calculations.

Structural analysis was performed predominantly using traditional methods described previously. In addition, code was written in Microsoft Excel¹³ to aid in component analysis. A bulk of the research performed by the structures team involved the development and use of new composite materials technologies resulting in lighter, stronger, and more efficient structures. Final weight estimations were obtained using actual weights if possible. Engine weights were provided by Zoche Aero-Diesel⁹ and Williams International; structural weights were calculated from historical data and CAD models. Statistical methods were used to estimate composite element weights.

Highly developmental technologies were researched in the study of an autonomous flight option. This involved research into current and forthcoming technologies as well as the design of unique components.

Considerable effort was spent designing a fully ergonomic cockpit. This included the use of HumanCad⁸ and U.S. Air Force data to analyze 95^th percentile human sizing. Instrumentation was designed to reduce pilot workload through convenience and ease in reading. In addition, in flight testing of a current general aviation aircraft was conducted to observe which instruments were used most frequently. This information was used to place components in a logical visual scanning order.

Design for manufacturing resulted in analysis of construction techniques and the decision to outsource component manufacturing. Plant layout analysis was conducted to determine the most efficient path that the aircraft subassemblies would follow. Along this path, an ergonomic assembly of equipment was chosen to reduce employee injury and fatigue.

Cost analysis was completed using Jan Roskam’s³ method and Microsoft Excel¹³. A spreadsheet was used in order to keep data current, insuring that design changes worked towards lowering the cost.

All of the above design components are discussed briefly in the following sections and in detail in Appendix E.

The Propulsion team researched a wide variety of power plants including pure electric, solar power, hybrid electric, fuel cells, and conventional systems. Although alternative forms of energy will transform the transportation industry of the future, the practicalities of today make such systems infeasible for aircraft propulsion. Many conventional aircraft engines were surveyed, resulting in the selection of the Zoche Aero-Diesel⁹ as the primary propulsion system and the Williams Turboprop as the optional system. Table 2 shows a sample of the engines researched.

The Zoche Aero-Diesel is an excellent choice for a propulsion system. It is an eight cylinder radial engine with four cylinders in two rows, highly charged, direct fuel injection, air-cooled, two stroke cycle diesel. It weighs 271lb and produces 300hp with a Brake Specific Fuel Consumption of 0.357lb/hp.hr. No other reciprocating engine in the market can match its specifications.

The Zoche engine costs less, has a lower SFC, and has a higher power to weight ratio than its quality Textron counterparts. No other piston powered engine researched comes close to the Zoche’s SFC or power to weight ratio. It has half of the weight and half of the frontal area of an opposed-cylinder spark ignited engine rated at the same power.

Direct fuel ignition engines (DFI) such as the Zoche are more fuel-efficient than typical spark ignition models. Efficiency is improved with advanced turbo-charging and low-heat-rejection technology. The high fuel economy of the Zoche ZO-02A is due to the greater energy content of diesel fuel in combination with the thermal efficiency of the diesel cycle. The ZO-02A also benefits from diesel technology’s low emissions. Without after-treatment, diesel exhaust emissions are as low as a typical gasoline engine that is equipped with a three-way catalytic converter.

The designers at Zoche incorporated engine control ergonomics into their design; all functions are operated from a single lever. During operation, mixture, alternate air, auxiliary fuel pump, magneto switches, mandatory temperature, boost and power restrictions do not need to be monitored, thereby reducing pilot workload and making the aircraft easier to fly.

From a mechanical standpoint, Zoche engines are reliable with low maintenance costs due to a lack of reduction drives, small parts count, and use of reliable diesel components. Reliable startup can be achieved in all weather through a patented pneumatic start system.

As the Williams Turboprop is still in its design phase, only preliminary information is known. These data show that the turboprop will provide 450 shaft horsepower (shp) with a weight of 170lb and a 0.56lb/shp.hr SFC. The optimism of these numbers has been verified by the Arrius 2 Turboprop engine; this Austrian engine provides 634shp at a dry weight of 191lb and a 0.573lb/shp.hr SFC. The major difference between the Williams and other competing turboprops is in price. At the projected cost of $100,000, the Williams Turboprop is one-half to one-third of the price of its competitors. Like the diesel engine, the turboprop has maintenance advantages including fewer wearing parts and extended time between overhauls. Complete information regarding alternative energy research and propulsion system selection can be found in Appendix E-1.

The main sources of noise in a general aviation aircraft are the engine and propeller. Noise in the cabin decreases pilot and passenger comfort; to prevent this, The VicTor has many features that suppress cabin noise. A compact three bladed propeller and well balanced engines serve to reduce noise production dramatically. Also, engine exhaust is directed down and away from the fuselage at the bottom of the nose. Although high frequency noise is associated with both engines, this noise is largely blocked from entering the cabin by the use of closed-cell acoustical foam Further details can be found in Appendix E-1-5.

In an effort to improve The VicTor’s performance the incorporation of a forward swept wing resulted in a weight savings due to structural simplification as well as an aerodynamic benefit of improved low speed handling and delayed tip stall.

The desire for a high maximum lift coefficient and a large drag bucket defined airfoil selection criteria. The low drag criteria led to research into natural laminar flow cross sections. Natural laminar flow designs have proven to be a realistic method of producing very low drag flight at all conditions, and incorporating this technology would allow The VicTor to fly even more efficiently, however the aerodynamic qualities of these airfoils did not meet design performance requirements. Also, there are currently unresolved concerns regarding sudden loss of lift in fully laminar airfoils due to slight surface imperfections (slight icing, rain, or insect debris).

The NACA 63₁-412 was chosen for the main wing and this airfoil does provide limited laminar flow benefit. Figure 4 shows a cross section of the NACA 63₁-412 airfoil¹⁶.

Figure 4

Wing sweep was defined by a quarter-chord sweep of 10.6 degrees (^o). The wing was mounted at an incidence angle of –2.0^o, resulting in a cruise lift coefficient of 0.1. This allowed for The VicTor to be flown level at its lightest weight. In its heaviest loading condition, The VicTor would be flown at a slightly higher angle of attack in order to produce the necessary lift. This allowed The VicTor to cruise in its drag bucket; the lift to drag ratio would remain favorable for lift coefficients up to 0.6. Thus, flight would be efficient even in moderate climbs and maneuvers. Appendix E-2 presents full details of these analyses.

In order to minimize The VicTor landing speeds, high lift devices were required. Fowler flaps were considered, however, the trailing edge of the 63₁-412 was too thin to effectively accommodate the necessary structure and deployment mechanisms.

Conventional tail, canard, and three-surface control systems were investigated; extensive but computations and studies dictated the selection of a cruciform tail. Simpler split flaps were then examined. As they could not wholly provide the desired additional lift, drooped ailerons, or "flaperons", were added. These two surfaces were linked via the fly-by-wire system, freeing the pilot from having to control both flap and flaperon deployment. These high lift devices allowed a touchdown speed of 52kts and a stall speed of 47kts for the diesel powered aircraft and speeds of 51kts and 46kts for the turboprop powered aircraft. Figure 5 shows the wing layout.

Both tail surfaces used the NACA 0009 airfoil. This airfoil was chosen largely for its common use in today’s general aviation industry. The horizontal tail was mounted in an inverse cruciform configuration to prevent the rudder from being entirely blocked by the wake of the horizontal tail in the event of a spin. Also, a dorsal strake was added to increase side drag in the event of a spin. Tail design specifics can be seen in Figure 1. Additional details regarding tail and flap design can be found in Appendix E-2.

Sweeping the wing forward introduced design challenges pertaining to aeroelastic divergence and flutter. To resolve these challenges a composite structure was designed. The wing is built up from a composite wing box and leading and trailing edge pieces, as shown in Figure 6.

The main load-bearing component is the filament wound wing box. This piece is formed by winding filament around a mandrel and curing it vertically, allowing the mandrel to melt away. This forms both a strong structure and a fuel-tight wet wing fuel tank. Filament winding was chosen in order to control the exact layup of the composite structure. By aligning the different layers properly, the wing can be made to twist down as the tip bends up; this coupling of bending and torsion increases the divergence speed of the wing.

The trailing edge component of the wing houses everything needed for the flaps and ailerons. The leading edge component has space for the wiring. As these components are non load-bearing, they are attached directly to the wing box with an adhesive. A complete discussion of wing structural design can be found in Appendix E-4-1.

Working closely with the ergonomics team, a considerable amount of time and effort was put into creating a spacious and comfortable cabin. The cruising altitude of 15,000 feet requires the aircraft to have a pressurized cabin. This increases weight and structure. In order to design efficiently, a Finite Element Model or the cabin and luggage compartment was constructed and an analysis completed in order to obtain optimum skin thicknesses. Additional weight was saved through the combination of major load bearing bulkheads. For example, the aft portion of the door and the main gear were mounted on the same bulkhead, as were the wing box and the rear pressure bulkhead. Further details are in Appendix E-4-2.

If The VicTor’s design was to revitalize the general aviation industry, it had to outperform all current aircraft in its class. Surveys taken in recent years have shown that general aviation pilots want faster, more powerful airplanes, and The VicTor delivers.

Initial performance calculations determined thrust, drag, power required, and power available versus velocity. A power setting of 75% was used for cruise condition calculations. A very conservative propulsive efficiency of 80% was assumed.

The cruise speeds greatly exceed that found in other similar general aviation aircraft; the Cessna 182 Skylane cruises at a speed of 140 knots, with a maximum speed of 145 knots¹⁷.

The VicTor has very impressive takeoff performance. A comparison between takeoff characteristics of The VicTor and the Cessna 182 Skylane is shown below.

Climb characteristics often tell the most about an aircraft’s performance, and it was here that The VicTor truly excelled. As with takeoff, it was the powerful, lightweight engines that gave The VicTor the ability to surpass all other general aviation aircraft. The VicTor’s climb rates are reminiscent of World War II fighters, especially when powered by the turboprop. The maximum rate of climb at sea level for this propulsion system was 4,900 feet per minute (fpm); the diesel-powered model climbed at 3,000fpm. Both The VicTor configurations have performance ceilings well above 20,000ft, however, the decision was made to restrict flight at this altitude. To do this, a system was linked to the altimeter that would automatically reduce engine power to prevent the aircraft from climbing above this imposed ceiling for safety reasons.

The differences in engine specific fuel consumptions (SFC) resulted in significant differences between the diesel and turboprop in range and endurance values. The diesel powered VicTor could near transcontinental cruise with a maximum range of 2,270 nautical miles (nmi) and the turboprop powered VicTor with a maximum range of 1,475nmi. The VicTor’s maximum endurance was also impressive.

The use of 30% chord split flaps and 20% chord drooped ailerons (flaperons), allowed the diesel powered aircraft to have a touchdown speed of 52kts and a stall speed of 47kts. The turboprop powered aircraft had a touchdown speed of 51kts and a stall speed of 46kts. Landing roll distances calculations yielded a ground roll of 784ft for the Zoche model and 762ft for the Williams. Appendix E-6 presents complete performance information.

An ultimate goal of this design was an affordable, within current aircraft prices, fully autonomous vehicle. Current technology has proven that full autonomy is possible; unfortunately, current air traffic control systems make full autonomy for a general aviation aircraft a logistical impossibility. A logical alternative was to develop a system that could adapt to future technologies, including the "Highway in the Sky"¹. To incorporate these ideas, a computer system was needed to control the aircraft and monitor its systems. The computer had to be upgradable in order to account for changing technologies.

Because of their popularity and low cost, the integration of a laptop computer that would plug into the airplane’s flight computer was initially considered. Unfortunately, research showed that this system would be overly susceptible to vibration and impact and therefore unreliable. An alternative was a CDROM type disk drive mounted in the cockpit, that would update the flight computer’s software on a regular basis. Because of the same limitations of the laptop computer, this was also discarded. The use of a system similar to that used in large commercial aircraft was then considered. These systems are very reliable, and could be used in line with an electronic bus system that would aid in expandability. In conjunction with the flight computer, the instruments need to be adaptable to a fully autonomous control system. The primary goals for these instruments were to reduce pilot workload and display the necessary information clearly and in a sensible sequence. One possible solution was a digital knee-board with buttons on either side of the screen for menu selections. This was conceived as a laptop screen attached to a remote computer that allowed the pilot access digital maps, flight plans, and checklists. Although this design possessed many strong points, it required the pilot to change his point of attention too often. The final decision was to employ a Cathode Ray Tube (CRT) mounted on the instrument panel. This display would use Automated Teller Machine (ATM) style buttons to enable the pilot to make selections from menus displayed on the screen. The CRT would display engine data, digital maps, check lists, and flight plans.

The VicTor’s navigation will be largely dependent on GPS, with backup from the current VOR navigation system. Traditional navigation and communication radios will be mounted to the right of the CRT display. This setup was chosen because of its ease of use and familiarity.

There are several goals behind the utilization of an advanced integrated avionics system. Introducing easier to use thrust management systems, automated navigation planning, improved cockpit display and flight control ergonomics, automated trim control, electronic spin and stall recovery, and a fully automated flight system will improve novice pilot learning curves. Improved warning systems and compact data displays of flight parameters will help decrease pilot workload. Electronic displays will reduce dependency on the use of conventional charts and procedure templates. Increased all-weather flying capability can be enhanced by using vertical moving maps, global positioning system (GPS) and satellite or cellular data-link. Future general aviation navigation will be GPS based with cross-referencing to conventional ground-based navigation systems and on-board inertial reference systems. An on-board flight management system can control fuel mixture based on atmospheric parameters, improving engine performance. With progress in avionics technology, the free-flight air traffic environment, the "Highway in the Sky", will become possible.

In order to create a functional autonomous flight control system, pilot capabilities must be fused with technology. To see how this might be done, current commercial integrated avionics packages will be described below.

• A Flight Management System (FMS) is essentially the "electronic pilot". The FMS is responsible for flight guidance—lateral and vertical control of the aircraft flight path, cross-referencing navigation and inertial systems, monitoring the aircraft flight envelope, and control of engine thrust.¹⁸

• Attitude Heading Reference Systems (AHRS) or Inertial Reference Systems (IRS) is an extension of the IRS concept, where the gyro computed roll, pitch, and yaw rates are integrated over time to give roll, pitch, and heading changes.

• Global Navigation Satellite System (GNSSU) is a satellite-based positioning system consisting of satellites, ground control, and GPS users. Differential GPS (DGPS) is an improvement on the GPS method of determining position. It operates by referencing satellite timing signals to a geographically known ground receiver, from which the error can be determined. The true position of the user’s receiver is then obtained from the difference between the satellite-based position and the error. The DGPS system is shown below in Figure 7.¹⁹

• An Air/Ground Data Link allows communication between the Air Traffic Controller (ATC) and the FMS system onboard the intended aircraft.

• The Air Data Computer (ADC) use conditions outside of the aircraft to compute altitude, vertical speed, calibrated airspeed, and true airspeed.²⁰

• The Instrument Landing System (ILS) was developed around the VOR/DME ground station concept. It offered all-weather high precision landing guidance to equipped airports.
• The Satellite Landing System (SLS) is now revolutionizing instrument-assisted approaches. A GPS stand-alone receiver provides an unseen level of situational awareness and guidance to the target runway.

• Traffic Collision Avoidance Systems (TCAS) are selective addressing transponders—each aircraft listens for other aircraft transponder broadcasts.
• Weather Avoidance Systems (WAS) rely on expensive onboard radar systems to display likely weather hazards (windshear conditions, areas of large turbulence, and thunderstorms). This option is not economically viable for small general aviation aircraft; a weather service integrated with the cellular communications network is needed.

• A Thrust Management System is a combination of digital computer hardware and analog feedback architecture directly linked to propulsion controls and sensors.
• Flight Surface Control Systems such as mechanical, hydraulically boosted, or fly by wire
• Flight Control Computer receives either pilot or FMS control input and converts these inputs into control variables for the actuator feedback systems.
• Electronic Flight Instrument System (EFIS) was developed to improve cockpit and flight environment situational awareness. Recent advances in digital display technology have allowed for the replacement of EM flight directors with Cathode Ray Tubes (CRT) and Liquid Crystal Displays (LCD).
• Data Bus System is an avionics system which is analogous to the central nervous system of a human body. It allows fast communication between electronic components that share data.

• Microcontrollers are basically a scaled down Personal Computers. The advantage of microcontrollers lies in their small size and low cost. Relative costs range from $5.00 to $100.00, and the processor is approximately one square inch. The real advantage of using a microcontroller based system is its superior reliability over large chip based systems.
• Triple Redundant Systems imply that operationally identical systems are installed into an aircraft in triplets. This cross-referencing, coupled with intermediate diagnostic checks of each system, ensures a high reliability standard.¹⁸

These systems are described in more detail in Appendices E-9 and E-10. The Virginia Tech Autonomous System Design (VTASD) incorporated many of these systems in its design and is described in the next section.

The driving forces behind the Virginia Tech Autonomous Flight System design were:

• Reduce the cost from that of existing autopilot systems.
• Integrate technologies that will be essential for future fully autonomous flight.
• Utilize technologies that will be essential in a future free-flight "Highway in the Sky" environment.

Several existing commercial avionics system types were integrated in the Virginia Tech design along with the VTASD data bus and redundancy schemes. As with commercial designs, the VTASD is divided into Flight Control, Management, and Pilot Interface Systems. Assembling the electronics "in-house" reduces markup of avionics. The computer design and integration of the VTASD system is itemized below. Full details can be found in Appendix E-10.

• Data Bus System will be developed and manufactured in-house. The cost of the data bus architecture and connectors is projected to be $3500 for each unit. Figure 8 shows the block layout of the data bus system.

• Microcontroller Integration will implement microcontrollers as the processors for the FMC, SLS, Electrical Power Monitor, Communications Hub, AHRS, Thrust Management System, ADC, both Primary and Secondary FCC systems, Diagnostic Computer, and Actuator control systems. These microcontrollers will be manufactured by separate companies to fall in line with the triple redundancy initiative.
• Software Development will be completed in-house by the Virginia Tech VTASD team. This part of the project will be the most demanding Non-Returnable Engineering cost because of the necessity of triple redundancy.
• Flight Management System (FMS) essentially operates in the same manner as commercial avionics. However, the hardware differs from commercial systems in that there is further subdivision between the FMS and its subsystems.
• Attitude Heading Reference System (AHRS) that utilizes cheaper, high quality fiber-optic gyroscopes manufactured by Hitachi. These gyros have been predicted to cost $100 each in the near future.²¹
• Global Positioning & Communication System is based on the GNSS-Transponder produced by the Swedish. The navigation satellite receiver operates in the same manner as any other DGPS receivers.
• Air Data Computer (ADC) and Thrust Management System (TMS) will incorporate a microcontroller configuration.
• Actuator Control System (ACS) will implement FCC and FBW technologies. The control surfaces are then mechanically actuated by a DC motor and worm gear. The VTASD mechanical implementation is shown in Figure 9.

• Flight Information Systems or Integrated Avionics System (IAS) will be devoted to the management and presentation of information to the pilot which will also include communication automation.
• Electronic Library System (ELS) is a storage system that takes advantage of today’s computer technology. It is possible to store virtually all information required by pilots on CD-Rom disks or other forms of electronic media for en route navigation charts, operating manuals, and checklists.
• Automatic Dependent Surveillance (ADS) is a data link that will provide aircraft position information to controllers, airports and pilots. Through the use of a satcom data link, ADS responds automatically to ground-system requests for aircraft position reports.
• Integrated Cockpit Displays will include primary conventional electromechanical instruments complemented by a multifunction display (MFD) unit. The MFD will be based on the Onboard Avionics Synergistic Information System project, "OASIS", a study of Air Force technology transferred to GA applications. The OASIS MFD integrates key cockpit instruments and aircraft sensors, providing comprehensive situational awareness through revolutionary two- and three-dimensional displays.²²

The cockpit of this aircraft was designed from the inside out. During an in-flight test of a Cessna 172 Skyhawk, auditory levels were recognized to exceed safe levels over long periods of time and that the overall utility of the yoke design and throttle placement was poor. These design problems, along with poor visibility and a lack of adjustability, will be solved in The VicTor’s cockpit through an improved design.

Human anthropometric data was gained from United States Air Force pilot data; HumanCad⁸ software allowed for the virtual manipulation of 95^th percentile males. Use of this software allowed for verification of sizing, and elimination cramping and out of reach areas; the movement of independent body parts was simulated, eliminating the need for a full scale mock-up (Figure 10).

The two pilot’s seats were designed to be fully adjustable in the longitudinal and latitudinal directions. The rear bench will have a 60/40 split design which will allow the seats to fold down completely in order to load luggage/etc., or only partially fold down to allow for large objects as skis to protrude while still allowing for rear passengers.

The side stick and engine control were designed to adjust to the pilot’s anthropometric needs while integrating safety into the design of the cockpit. The integrated armrest/side stick was termed the "Sidekick". The Sidekick and engine controls (Figures 11 and 12) are attached to the pilot’s seat can both extend telescopically and raise in order to give the pilot the maximum comfort. This adjustment allows for a wide range of arrangements that will not cause fatigue to the pilot and will reduce the pilot’s search therblig—the amount of time needed to acquire a control. The knob shapes were acquired from Air Force standards and the drawing of the system can be found in Figure 12.

This design is safer for the pilot in accidents and emergency situations because the flip-up design will allow for easy egress. In crash situations, the Sidekick and engine control will be out of the forward path of the pilot whereas the traditional yoke design lies in the path of the pilot and can cause injury. The aircraft controls also allow for the ability to integrate aircraft airbags as there are no impediments in the path of the deployed airbag such as a yoke or center stick. The airbags are tied into the flight management system in order to eliminate the possibility of misfires during flight. In addition, the soft rubber instrument panel, will cushion impact if the airbag system fails, reducing serious injuries sustained from current metallic and hard plastic instrument panels. A three-point seat belt system will also secure the pilot and co-pilot during flight and in the event of an accident. This will bring The VicTor to the level of automobile safety standards.

In order to improve visibility and decrease pilot workload, a low profile instrument panel was designed. The instrument panel contains a visor at the top to eliminate any glare that could interfere with control viewing. The instrument panel will include a center swiveling CRT that contains navigational and control devices that are a digital design that supports the use of software and multiple screen displays. A complete three dimensional layout of the cockpit is shown in Figure 13. Further information is in Appendix E-11-1.

The major factor in determining whether to manufacture or outsource components was the use of composites. The large capital investment required for composite fabrication machines made the outsourcing approach more feasible. Having the major assembly products outsourced allows for greater flexibility in future product changes. The manufacturing system within the plant implements a Just In Time (JIT) delivery system; Total Quality Management (TQM) systems will be implemented due to strict safety standards.

The facility design will improve the general aviation industry by optimizing material flow, increasing throughput, and decreasing flow time. Although it will require strict contracts with suppliers, the JIT system will decrease the non-value added process of inventory while the Design For Manufacture (DFM) method will decrease the number of individual parts and assembly steps. High quality aircraft will be passed on to the customer, on time, at low cost for years to come.

The current general aviation industry is lagging in technology, as are the techniques utilized in the production of these aircraft. High inventories and lengthy production times are the result of poor design in both the plant and the parts design. Just In Time delivery systems and Design For Manufacture techniques will help eliminate the problems of excess inventory and large production time; inventory levels should be kept to a minimum because it is stagnant and offers no value to the aircraft. The Just In Time approach led to the combination of products and product families within the plant; this approach required the use of kanbans with a cellular approach in order to be efficient.

Total Quality Management will also be facilitated with this new cellular approach because the production can be highly personalized to meet the customers’ expectations. With each cell independent of another, the customer may be highly specific in preferences. Each value-added process may be personalized by the customer. Each cell will be connected to the master database via a LAN and personal computers. Utilizing this system sends data to the statistical process control area, which will determine whether the outbound quality is within the control limits. This integration will improve quality control within the plant, and allow for real-time feedback to the supply chain. The sharing of this data will facilitate in the management of inventory and the control of quality systems throughout the plant.

It has been assumed that the cabin, tail section, wings, engine and cowling will be received separately due to outsourcing. The shells will loaded sideways and taken to the gear installation area. After the gear is installed, the cabin is rotated until it is upright and the harness system is attached. This harness system is connected to an overhead rail system that moves the cockpit shell through the next section of the facility. This harness will level the aircraft and allow for vertical and horizontal movement without any operator effort. This allows the aircraft to be placed at the correct ergonomic height for the manufacturing operators.

The shell is then transferred along the line where interior systems are installed through the rear of the shell. The cabin is transported to the staging area via an Automated Guided Vehicle (AGV) which will follow a magnetic path in the floor. In the staging area, the aircraft is placed on an overhead leveling fixture which will allow the mating of the tail section, the engine systems, and cowling. After the sections have been joined, the aircraft is lowered to rest on its gear. From here the aircraft is taken off of the fixture and rolled to the wing placement area. In the wing placement area the wings are attached along additional wiring and fuel systems. The aircraft is then taken to the aesthetics area where detailing and window installation is performed. After this, the finished airplane is taken to the quality control area for inspections, where it will continue on to an actual flight test which completes the quality control inspection process. When the inspection process is completed, the customer is notified and the aircraft delivered. The complete layout including sizing can be seen in Figure 14.

This manufacturing/assembly approach will include Design for Manufacturing and Assembly (DFMA) which will result in the reduction of parts by combining many separate assemblies. The use of composite design will help in the assembly process by integrating several parts into one, thus reducing the overall assembly time. DFMA has proven to be a successful approach reducing manufacturing time and cost reductions. Fasteners are currently being researched in order to reduce costs and improve safety from the traditional rivet style of assembly. Fasteners will also coincide with the use of composites since the subassemblies can be designed to accept the fastener pieces and result in tighter tolerances. The majority of the plane assembly will be non-automated except for the use of some ergonomic lift devices. Details regarding the manufacturing process are located in Appendix E-11-2.

Both electric resistance heating and electro expulsive deicing methods were studied but rejected due to power requirements and the possibility of electromagnetic interference with the fly by wire system. More conventional methods chosen include pneumatic deicing boots with built in ice-detection sensors on the wings, canard, and tail, and a standard shaft mounted deicing fluid spray for the propeller.

One of the key factors in the design of any new aircraft is cost, particularly when the goal is to aid in the revitalization of the industry. Therefore, it is imperative that the airplane be designed with all the amenities and technological advances needed to attract buyers, while keeping in mind that the aircraft must be affordable to many people. For this reason, it is a necessity to control the cost of the aircraft throughout the design process.

Several preliminary assumptions were made describing the personnel involved in the design and manufacturing of the aircraft. Conservative estimates assumed that all personnel involved would be highly qualified and well paid. These assumptions provided the data for engineers, draftsmen, tooling, and manufacturing pay rates. To insure that the estimates reflected current dollar amounts, a cost escalation factor was used.

The final aircraft cost proved to be highly dependent on several factors; the factors which provided the most drastic changes were: take off gross weight, maximum velocity, and the total number of aircraft produced. Figure 15 shows the relationship between production and cost.

Aircraft Cost versus Total Number of Aircraft Produced

Based on these calculations a sale price of $242,000 is expected. This is reasonable in comparison to a Cessna 182 with a basic avionics package selling for around $210,000 ¹⁷. The affordable cost of The VicTor is the direct result of using modern manufacturing techniques and a streamlined organization. The efficiencies of the organization and the continuous improvement of our manufacturing operation will allow us to produce between 4000 and 6000 aircraft over 30 years. The influx of affordable yet advanced aircraft will ignite the general aviation marketplace.

A single aircraft is not enough to revitalize the general aviation market, however it can begin the needed cycle. Revitalization of general aviation is dependent on numerous industries, particularly modern, high technology enterprises. High technology will provide necessary advances in manufacturing, electronics/computers, communications, propulsion systems, materials for manufacture, and manufacturing techniques. The VicTor incorporates all of these ideas to provide the ultimate in a comfortable, high performance aircraft at the lowest possible price.

To reclaim general aviation’s position in the transportation community, The VicTor will attract buyers who are familiar with these innovative technologies. This population is typically upper-middle class, and can afford an advanced aircraft. Due to these initial purchases, it is believed that supporting industries will begin to produce components on a large scale, thereby lowering acquisition costs. Lower costs in production will encourage other aircraft manufactures to design newer, more advanced systems. This cycle can be seen in today’s personal computer industry; as advancements are made in technologies and new competition emerges, products become more accessible and less expensive for consumers.

The VicTor’s design is sound and will attract the large capital investment needed for startup. From this initial capital, the manufacturing facility can be acquired. Personnel will be hired once the facility is acquired, and component suppliers will be secured. One possible means of raising capital and securing suppliers would be to give each supplier a share in The VicTor operation. This would insure that components would arrive on time with high quality, products they are proud to put their name on.

In order to generate interest, carefully targeted advertising would be necessary to reach aviation enthusiasts, as well as persons seeking a high performance commuter aircraft. Television and radio stations would be chosen for the appropriate demographic market; examples of some television specific market stations are CNN, MSNBC, DISCOVERY, and TLC. While advertising on the radio would prove more challenging, talk radio stations would be most likely to carry The VicTor’s advertisements.

Throughout the production lifetime, The VicTor’s design concept will steadily move toward autonomous flight. Only the necessary advances in supporting technologies such as air traffic control hinder this process. As technology progresses, The VicTor will steadily transform from a piloted vehicle to an "operated" vehicle. The designation of "operator" will not demand as much training or licensing regulation as the current system requires for pilots.

Rather than resurrecting general aviation with the redesign of an outdated aircraft, The VicTor takes flight in today’s market, soaring to tomorrow. Clearly, The VicTor can outperform nearly any general aviation aircraft; once in production, The VicTor will be the benchmark against which other aircraft will be measured. Through modern, unconventional design concepts, The VicTor allows high performance flight in unmatched comfort and style. Combining spirited maneuverability with ease of control, The VicTor is attractive to all manner of today’s pilots. The fully autonomous flight regime, the "Highway in the Sky," will expand this group even farther, to the aircraft operators of tomorrow.