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InnoCentive Program:  

Topic Number:  

Title:  

Your name Benjamin L. BerryPhone number: 503 320-1175Email address: Website address: Past experience working on similar projects:

Special Operations Transport – Air Force Research Lab - AFRL

“AirShip Endurance V9”An AirShip VTOL UAV Transformer

Benjamin.berry@comcast.netwww.AirShipTG.org

SBIR Air Platform in 2011

Research & Technical Areas:  Original Detailed Description and Requirements.The U.S Air Force is seeking new and innovative ways to move people in and out of potentially hostile areas without being detected.  This challenge is created by the Air Force Research Laboratory (AFRL) and requires a design for a transport system that will move two Passengers or people and their equipment into and out of all types of terrain. The mode of transportation is up to the Solver, but clear performance specifications must be met. The Seeker believes that technologies enabling the key functionality of the requested transport system are available and that only an

16.060.0Span (Inches) at Rest

60.0108.0Span (Inches) at Flight

8Tip Chord (Inches (trap)

0.3660.228Taper Ratio (trap)

1.7086.865Aspect Ratio (gross)

207.41,128.0Area (Sq. Inches) (gross)

V-WING TAILWINGAIR/VEHICLE Critical Dimensions

16.060.0Span (Inches) at Rest

60.0108.0Span (Inches) at Flight

8Tip Chord (Inches (trap)

0.3660.228Taper Ratio (trap)

1.7086.865Aspect Ratio (gross)

207.41,128.0Area (Sq. Inches) (gross)

V-WING TAILWINGAIR/VEHICLE Critical Dimensions

108.0

76.3

39.5

108.0

38.0

24.0 30.0

47.0

18.0

innovative design that integrates those technologies is needed.  The seeker is completely open-minded as to whether the solution is a vehicle or some other form of transport.  

The purpose of the challenge is to provide transportation of two people and their equipment from a location “Alpha” to a location “Bravo” and from location Bravo to location “Charlie”. Alpha, Bravo and Charlie would be ground locations each at their own ground altitude of between 100 ft above mean sea level (MSL) and 7000 ft MSL. Alpha and Charlie would each be separated from Bravo by a distance of up to 30km in any direction with various types of terrain intervening. Precision of transportation to locations Bravo and Charlie must be within +/- 30 ft and the transport system should be inaudible to individuals on the ground 300 ft or more away from Bravo or on the ground within 300 feet of the transport path. 

A CV-22 or equivalent aircraft with an available payload volume of 5 x 5 x 18 feet will be available to deliver the sought transportation solution to the ground at location Alpha. The same aircraft will be available to pick up the transportation solution at location Charlie.  It must be possible for a 2-person transported team to prepare the transport system for operation within 4 hours – this may include unpacking, assembly, servicing, calibration, etc. at the Alpha location or inside the supplied aircraft.  Typical usage scenarios for the sought solution might be similar to the following: A 2-person team departs

location Alpha in the sought transport system under cover of darkness and is transported with minimal user interaction to location Bravo. 

After some operational interval the 2-person team would then be transported out of location Bravo with

AirShip awarded Linus Pauling Innovative Company of the Year

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minimal user interaction to location Charlie an additional 30 kilometers away. Exit from location Bravo should also be quiet, i.e. barely audible to individuals 300 ft away from the transport system, unless it is fast and sudden enough that detection becomes irrelevant (i.e. hostile forces cannot react). 

The area between locations Alpha and Bravo may be mountainous terrain which may include steep cliffs, ravines, valleys, rapid-moving rivers, etc. The required transport system must be able to operate at night and cross terrain that any well-equipped and highly trained person would be able to traverse in daylight on foot. The Seeker requires that the proposed transport system is faster than trained personnel covering the same ground on foot, but even faster solutions are preferred. 

Solvers should assume that the terrain to be covered is sparsely populated by hostile patrols of individuals whom we wish to not observe the transport process. Radar detection is not relevant to this challenge.   Seekers should assume that GPS signals are available for navigation.  Guidance and navigation of the solution system should be either autonomous or simple enough that the 2-person team may remain alert to threats from hostile patrols and deploy their personal weapons or other equipment accordingly. 

The Seeker requires an innovative design for a prototype transport system to autonomously transport two personnel and their equipment over rugged terrain, quickly and without detection. There may be many aspects to this challenge which should be detailed by the solver including the transport system concept, structural, mechanical, electrical, software, digital, optical, acoustic, and other design considerations as needed.  The Seeker encourages Solvers to integrate all aspects of the required solution into their proposal, but also values proposals that are particularly strong in any one or more of the above aspects. The Seeker anticipates that successful Solvers may be invited into contractual engagements with the Air Force Research Laboratory (AFRL) to develop their transport system designs. 

Solver’s Solution

Lateral In-Flight View of AIR/VEHICLE VTOL UAV Transformer, “The AirShip Endurance V9”

The solver’s aircraft solution is designed as a Tier II vertical takeoff and landing unmanned aerial vehicle (UAV) for medium altitude and long endurance (MALE). This Special Operations air/vehicle is designed for diverse mission deployment. As a UAV, it is designed to transport 2-3 people without a pilot to forward operating bases (FOB); drive on prepared surfaces and off-road conditions; take off and land vertically to cross water, terrain or obstructions and avoid ambush or IEDs. The design has speed, maneuverability and range to perform "tactically relevant" missions on a hybrid fuel-to-electric power plant. The air/vehicle’s added mission extensions are a) medium altitude stationary surveillance, b) communications relay, c) ship-to-shore troop insertion, d) improvised explosive device (IED) avoidance, e) Special Operations Forces transport and resupply, f) medical evacuations, and g) remote payload emplacement. It meets the InnoCentive Special Operations Transport technical requirements.

Aerial View VTOL Hybrid Fuel to Electric Power

Anterior Under Carriage ViewNote: Three versions planned for AirShip Endurance air/vehicle. Engines and turbines are sized for the AirShip Endurance V5 (5 foot version) used for surveillance and reconnaissance. V9 is our 9-foot version used for 2 to 3 troops plus equipment and is proposed for the USRL’s Special Operations Transport RFP. V17 prototype is a 17 foot version that carries up to 4 troops and equipment.

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TECHNICAL REQUIREMENTS: Proposed designs should be for a transport system that will fulfill the following Technical Requirements:

The transport system should:

1.0 Transport at least two people and their equipment (700 lbs. total). The operator space should allow for the two people to move their weapons and hold the cargo (e.g. an injured person that could be on a litter).The air/vehicle is capable of transporting 2 people and their equipment with a total maximum payload of 1,000 lbs. The design includes in-flight slide forward or slide aft doors that allow for in-flight weapons operation and controlling cargo such as an injured person on a litter.

2.0 Have an operational range of at least 60 kilometers over mountainous terrain including up to 6,000 ft total difference in elevation. The air/vehicle design specification provides for a top speed of 300 mph (260 knots - nautical miles per hour), a significant nautical range. The aircraft is designed for reliability, internal and external sensitive acoustics, and an environmental sensitivity due to non-polluting benefits of its hybrid fuel-to-electric power plant. It has a maximum flight range of 500 Nmi over flat or mountainous terrain and has a 10,000 ft elevation maximum.

Lateral ducted fan turbines are equipped with two sets of three counter-rotating rotor blades (propellers). The aircraft has two lateral turbines each with six rotor blades for a total of twelve rotor blades. The lateral turbines are capable of rotating at 2,000 RPM. Two lightweight powerful turbo shaft engines drive the lateral turbines in excess of 1,250 Hp each. This yields a total of over 2,500 Hp in the two lateral turbines and 1,200 in the rear ducted fan turbine. The rear turbine can be either a dual counter-rotating ducted fan rotor or engineered as an air accelerator bladeless turbine powered by the dual turbo shaft engine’s exhaust. This horsepower is distributed to the three turbines during vertical takeoffs and landings and ensures the aircraft’s operational range.

3.0 Be able to cover territory that a highly-trained and well equipped person could cover on foot. The air/vehicle can cover straight-line air transit over territory that a highly trained and well equipped person could cover on foot.

4.0 Be able to cover the described terrain faster than a highly-trained and well equipped person on foot, the faster the better. Because of the air transit capability of up to 300 mph, the air/vehicle is designed to cover territory much faster than a highly trained and well equipped person on foot. The ground transit capability of 85 mph adds an additional mode of transportation that is faster than a person on foot.

5.0 Have a low acoustic signature (< 35 dB(A) at 100 meters), at least during arrival at ‘location Bravo’.  Quiet departure from Bravo is also sought, but is less critical if the noise duration is brief and the departure is swift. For arrival at “location Bravo,” the air/vehicle is designed to essentially glide in to the target landing site with its lateral turbines dialed down and its rear turbine fully engaged. As the vehicle reaches near 100 feet of the landing site the lateral turbines are engaged to slow the vehicle to a VTOL landing. Once landed, all turbines can be placed in idle mode or turned off. This approach will meet the <35 dB low acoustic signature requirement for arrivals. At departure, both lateral and rear turbines are fully engaged. With the lateral turbines ability to pivot up to 15-degrees, less power and less noise can still effectively work to VTOL-launch the air/vehicle as it flies forward during liftoff.

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Alternatively, the design calls for a rear Air Accelerator Bladeless Ducted Fan Turbine that is powered by the dual turbo shaft engine’s exhaust that forces air thrust through the inner lining of the rear ducted fan. This air accelerator turbine is used for forward motion with its 2,500 to 3,000 lbs of thrust and meets the (< 35 dB(A) at a 100 meters design requirement. During flight, the rear air accelerator is engaged and the lateral ducted fan rotor turbines are dialed down, thus reducing noise. For maximum lift, the air/vehicle can engage all three turbines briefly at landings and takeoffs, be they VTOL or runway departures.

Conventional comprehensive rotor analysis and acoustic measurements are capable of providing good correlations with measured noise data at low active blade amplitude settings. Predicted noise levels at higher active blade deflections (greater than 1.0 degree) deviate from measured values in both amplitudes and trends.

The air/vehicle’s lateral ducted fan rotor assembly is a propulsion system whereby its rotor fans are mounted within a cylindrical shroud (duct). The duct reduces noise and losses in thrust from the tip vortices of the fan, and by varying the cross-section of the duct allows the design to advantageously affect the velocity and pressure of the airflow. In the air/vehicle, the ducted fans have more and shorter blades than traditional helicopter rotors and thus can operate at higher rotational speeds. The operating speed of an unshrouded rotor is limited since tip speeds approach the sound barrier at lower rotational speeds than an equivalent ducted fan. The aircraft’s ducted fan assemblies use an odd number of blades (3) to prevent resonance in the duct. Eliminating the resonance prevents the tendency of the aircraft’s rotor fans to oscillate with larger amplitude at some resonant frequencies than at others. The goal at these frequencies is to eliminate even small periodic driving forces that can produce large amplitude oscillations, because the system stores vibration energy.

The air/vehicle pays attention to resonances occurring when the ducted fan assemblies are able to store and easily transfer energy between two different storage modes such as kinetic energy. However, there are some losses from cycle to cycle, called damping. The air/vehicle keeps damping small, whereby the resonant frequency is approximately equal to a natural frequency of the assemblies, which is a frequency of unforced vibrations.

Advantages of the air/vehicle being powered by ducted fan rotors are as follows: By reducing rotor blade tip losses and directing its thrust towards the back only, the ducted fan is more

efficient in producing thrust than a conventional propeller, especially at higher rotational speeds. By sizing the ductwork appropriately, the air/vehicle design can adjust the air velocity through the fan

to allow it to operate more efficiently at higher air speeds than a propeller would. For the same thrust, the air/vehicle’s ducted fan has a smaller diameter than a free propeller. The air/vehicle’s ducted fan rotors are quieter than propellers; they shield the blade noise, and reduce

the tip speed and intensity of the tip vortices both of which contribute to noise production. Ducted fan rotors can allow for a limited amount of thrust vectoring, something normal propellers are

not well suited for. This allows them to be used instead of tilt rotors in some applications. Ducted fans offer enhanced safety on the ground for humans working near.

The air/vehicle design accounts for the following requirements of ducted fan rotors: Delivers good efficiency while requiring very small clearances between the blade tips and the duct. Represents complex duct design that requires high RPM with minimal vibration. Manages weight increase as it is constructed from advanced composites. Prevents parts of the duct being stalled and producing drag at an angle of incidence of 32°.

6.0 Not be visually detectable at night The air/vehicle is well suited for non detection at night. Its key design technologies include adaptive low aspect wing structures, quiet rear air accelerator bladeless turbine and lateral ducted fan rotor propulsion, lightweight composite structures, advanced flight controls for stable transition between vertical and horizontal flight, hybrid fuel to electric powertrain, and a quiet rechargeable Lithium-ion electric-battery driven motor in-wheel drivetrain for ground transit.

To prevent visibility during night operations, the aircraft has an overall low profile and hugs the ground during ground transit. It employs a wide aerodynamic high lift/drag ratio fuselage with twin retractable canards on the fuselage just forward of the operations cockpit, and lateral integrated low-aspect ratio retractable wings set mid-

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range to rear on the air/vehicle’s mid-section. A horizontal empennage wing, with a slight pitch angled rear V-Wing, serves as an angled tail section where two in-set winglets with rudders rise from zero to a 45-degree position. Together, the two tail winglets of the V-Wing serve as stabilizers while the aircraft is in flight. For ground transit, the low aspect wings retract into the fuselage reducing the width of the air/vehicle to a manageable size for landing and ground transit, while the V-Wing returns to a flat 0-degree position. Three turbine assemblies supporting twin counter rotating ducted fan rotors are on each side of the air/vehicle’s longitudinal axis and a rear air accelerator ducted fan rotor assembly helps support this efficient configuration. This all ensures aircraft stability with reduced noise.

7.0 Not occupy more than 5’ x 5’ x 18’ in its storage/transportation configuration. With the air/vehicle’s transformer capability, the aircraft accommodates a wing span from 5 ft at rest, launch and landing to 9 ft at full launch and flight. This more that meets and accounts for the target 5 ft specified width required to support the “at rest” footprint requirement. At rest, launch and landing the air/vehicle nestles squarely within the confines of the required footprint. During air transit, the AirShip Endurance V9 is 9 feet long by 9 feet wide with all but a foot of the anterior mid section width taken up by the lateral ducted fan rotor assemblies. When extended, the rear upper right and left horizontal stabilizer winglets of the V-Wing account for a maximum aircraft height of 5 ft and a minimum aircraft height of 5 ft at rest with ground wheels extended. Within 45 seconds, the low-aspect ratio wings can extend and rotate out of the fuselage after vertical take-off and can be retracted into the fuselage after landing and at rest. During ground transit, the width is 5 feet conforming to the ground transit requirements.

For weight to strength efficiency, the air/vehicle has a titanium airframe and uses light weight composites-based exterior panels. Additionally, molded structural polyurethane is used for the interior life support and cargo /payload bay requirements.

The air/vehicle’s maximum lift payload is 1,000 pounds. It is capable of carrying 2 to 3 people for troop insertion missions (one forward placement and up to two mid placement plus equipment for a combined total payload of 1,000 pounds. For medical evacuation configuration, one forward placement medic, two medical evacuation litters and medical equipment allow for the 1,000 pounds. For pilotless resupply and cargo transit missions, all 1,000 pounds are available for freeform configuration.

For rescue mission configuration, the air/vehicle UAV can be dispatched through wireless communications to secure GPS coordinates for use as an empty weight aircraft capable of 1,000 pounds retrieval.

Aerial Ground Transit View Aerial Cross-Section View Airframe View

8.0 Be changed from storage to operational configuration by a 2-person team in no more than 4 hours and using only light machinery

Within 45 seconds, the air/vehicle automatically transforms from storage or ground transit to a flight ready configuration. This includes the low aspect wings extended from the airframe and the rear V-Wing winglets moving from a 0-degree to 45-degree position. Small hydraulic motors accomplish this transformation and no external machinery is required. Activation is initiated by an onboard cabin switch or a combination of smart phone or smart pad that uses secure communications for WIFI, cellular, or military radio remote control. One person can activate the storage to operational configuration on voice command, or hard wired onboard switch. Additionally, autonomously the vehicle is pre-programmed to change operational configuration given its air and ground transport missions.

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9.0 Navigate and steer autonomously (or with minimal operator control) to set coordinates in daylight or darkness and inclement weather conditions.

Autonomous Flight Control Strategies. The air/vehicle control strategies are targeted for completely autonomous flight navigation and steering, so the UAV is able to land even in the presence of loss of communications or inclement weather conditions. As the UAV is to launch and land in a small, possibly confined space, often near humans, safety and failure modes are well defined.

The air/vehicle will fly autonomously under directions of GPS to its destination.  Upon reaching the GPS destination, the air/vehicle can be guided to a landing on a 4 meter (13.1 feet) circular site by a Narrow Band Microwave Data Link. The microwave data link operates in the over 1GHz KU-Band range. This provides a narrow beam communications data link at the GPS destination for the aircraft to be guided to the center of the landing site. The air/vehicle utilizes multiple redundant anterior-mounted microwave dish antennas for signal accumulation.  For directional stability, four laser beams around the dish antenna are used to maintain precise accuracy of the aircraft descent down the microwave beam. This communications architecture provides the basis for autonomous descent and landing. The microwave data link allows for two-way digital communications between a pre-defined landing site and the approaching and descending air/vehicle UAV. In order to control the aircraft’s hover as it approaches final touch down at the landing site, information regarding wind velocity and direction, landing site motions and aircraft rate of descent is transmitted to the air/vehicle’s onboard central computer (Flight Control System). This approach provides the VTOL aircraft the capability of safe autonomous landings in complete darkness and during adverse wind gust conditions. For unsafe landing conditions, the aircraft’s stabilizing sensors maintain hover until the conditions for landing improve sufficiently for a safe landing. The air/vehicle’s Flight Control System is capable of locking onto the microwave beam during wind gusts. Upon final contact with the landing site, the aircraft automatically descends and lands.  The aircraft’s low profile, aerodynamic shape and weight secure the aircraft from being buffeted by the wind or other adverse conditions.

The air/vehicle’s advanced flight controls and flight management systems are designed to allow the aircraft to fly unmanned. The VTOL UAV can be dispatched for Special Forces Transport, downed airman recovery or for evacuating injured personnel from difficult to access locations". An autopilot system allows for effective unmanned operations. Using automated controls and flight-management systems, the air/vehicle is suitable for operations in built-up areas that allow the aircraft to counteract inevitable human errors among piloted aircraft, which make war zones so dangerous today.

Loss of Communications. Air/vehicle’s Flight Control System is programmed for its onboard computer control (OBC) to manage aircraft hovering and overall flight endurance. The system maintains aircraft hovering to a desired percentage of overall endurance capability and to autonomously fly the aircraft to complete predetermined missions. The aircraft’s onboard Inertial Navigator maintains real-time location determinations of the aircraft and in real-time provides location updates to the OBC. The OBC computes the real time percentage of endurance remaining. If the air/vehicle loses total external communications, the OBC will detect loss of communications and it will utilize the location data from its onboard Inertial Navigator to compute the remaining distance to the initial primary target and the distance to each alternative target. The system compares distance data to the endurance percentage remaining in order to continue the mission or to select an alternative preprogrammed mission target. If the endurance percentage remaining is not sufficient to carry out the primary mission or an alternative mission, then the OBC will compute the distance to an alternative safe landing area and autonomously direct the aircraft to land.

At the end of the mission, the air/vehicle UAV will fly to the landing destination. At the landing destination, the aircraft will be guided down to the landing site by a narrow-band microwave data link that will provide two-way communications regarding wind gusts and other local environmental conditions at the landing site. If unsafe landing conditions prevail at the landing site, the control strategy will cause the aircraft to generate an autonomous command to hover and not allow landing attempts until it is safe to do so. If the endurance percentage remaining is dangerously close to exhaustion, then the aircraft will land or a manual override

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landing decision can be invoked at any time from the ground using a handheld wireless remote controller. In this instance, no microwave-to-ground communication is required.

Safety and failure mode characterization. To maximize safety of the air/vehicle over other similar aircraft, a number of survivability characteristics are embedded in the design and development of the aircraft. This helps to eliminate human injury. For the pilotless aircraft, protecting people in transit and/or the injured during rescue flights is a prime imperative. To improve human safety, we integrated crash-protection technology into seats and restraint systems with off-the-shelf technology. Second, reducing the risk of fire and explosions was essential to reducing injury and fatality rates. Installing fire-resistant fuel lines, fuel tanks, and the use of fire-retardant fluids is designed substantively to reduce this cause of mishaps and failures.

Air/vehicle is designed as an autonomous ruggedized ducted fan-configured UAV that is ready for brutal operational terrain environments with components that stand up in harsh venues. Those components include the aircraft’s airframe, critical dynamic communications, sensors, laser and microwave-guided landing components, and critical flight systems. For extended pilotless missions, we have designed strategically placed lightweight ballistic armor ceramic tile protection for aircrew seats, cabin floor and critical rotor components. The aircraft’s motors, hybrid fuel-to-electric power train and ducted fan assemblies use advanced power plants, specifically designed for present and future relevant missions. Emphasis has been placed on excess power available at high gross weight/medium density altitude, reliability, and fuel consumption management. High performance from the aircraft’s power train and ducted fans set the design goal criteria. The design goal is to architect and design the right power train and propulsion systems first and then develop the VTOL aircraft around it, as has been done with tactical aircraft development.

The air/vehicle is considered a SMART aircraft because its software development incorporates flight maneuverability, collision avoidance, communications, and advanced warning and failure controls. The aircraft’s computer hardware is miniaturized to the greatest extent feasible and micro technology reduces weight and power consumption. Software development includes system modules for

Energy computer control

Electric battery controller

GPS-flight control Ducted fan rotor controller

Aircraft digital identification transmission

Rate of climb and descent controller

Smart phone digital remote control

Head up systems for information tracking, and

Automatic emergency descent

On-board secure computer interactive voice controller

Automatic flight control

The majority of application systems will be designed around standard operating system computers and widely used software tools. Custom developed software is used for many functions, but we also make use of marketplace software products as reusable software modules to facilitate integrated solutions. Real-time, redundant, on-board computers augment air/vehicle’s operational safety. The energy control computer will restrict the rate of climb and descent to remain within safe and efficient altitude levels. In case of an electric motor failure in flight, the energy control system senses the failure and automatically switches to Fuel Engine Power and lowers the aircraft at a safe rate of descent, utilizing the independent and redundant design of the twin ducted fan rotor assemblies.

Commercially available crash avoidance radar systems will be employed to prevent aerial accidents. The aircraft will be programmed to slow, hover, or maneuver away from potential crashes in the 50 to 10,000 feet altitude levels. These safety specifications will aid approval of the aircraft's air space operation by the FAA and other national and international government agencies.

The air/vehicle’s SMART software modules, advanced warning and correction systems advances the aircraft’s ability to operate safely beyond the capabilities of a traditional VTOL UAV. Many systems are activated

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automatically and inform the extended mission special operations transport by audio announcements and visual feedback; thus, entering in a new pilotless/autopilot VTOL UAV aircraft era that frees its passengers to concentrate on other operations during flight.

Air/vehicle incorporates off-the-shelf software for geo image analysis that will allow the VTOL UAV to land autonomous without crashing due to human error. For example, the Visually Assisted Landing System (VALS), lets aircraft use its onboard cameras to identify landmarks, adjust speed and direction accordingly, and navigate to a smooth landing. With takeoff and landing becoming fully automated, that's one less thing for human pilots to do.

Each turbo shaft engine is connected to one Ducted Fan Turbine and a Synchronous Rotor Drive interconnects the two lateral turbines. For safety, if one turbo shaft engine cannot transfer power to the other lateral turbine, the Synchronous Rotor Drive can continue to power both lateral turbines in a degraded mode. Additionally, should lateral engines and/or lateral turbines fail completely, the air/vehicle can still be powered and flown with only the rear turbine engaged in the vertical 90-degree position. In the case of lateral engine, lateral turbine, and rear turbine failure, the air/vehicle will deploy a large parachute for a gentle descent to the Ground. Once the air/vehicle is on the ground, it can be driven, quietly, using stored battery power and in-wheel motors at speeds up to 85 mph.

Proposed configurations. The air/vehicle UAV is considered a transformer aircraft because of its ability to transform autonomously and on command into multiple configurations that expand its mission’s capability.

Ground Transit View VTOL Launch and Land View In Flight UAV Transit View

Design Tradeoffs vs. Fixed Wing. In certain applications such as force protection, perimeter security, and aerial surveillance, the air/vehicle provides far greater utility than fixed-wing UAVs. The air/vehicle UAV operates much closer to an object of interest and provides a hover-and-direct stare capability to keep its sensors trained on an object; while fixed wing UAVs would be forced into a higher altitude loitering pattern where their sensors would be subject to intermittent blockage by obstacles and terrain.

Developing the air/vehicle UAV, the designers recognized the formidable task and wanted to consider the benefits and tradeoffs of helicopters, fixed-wing aircraft and hybrid aircraft. The pacing item is to develop/acquire the maximum thrust to weight turbo shaft motor configuration. Ultimately, since the performance of the air/vehicle depends strongly on the motor-power train and aircraft weight characteristics, this design proposal will lead to construction and test of the full scale prototype. To meet the aircraft maneuverability needs, entails demanding engineering challenges. Landing and takeoff from short, narrow, unimproved sites is the most difficult requirement to meet, but the air/vehicle compares favorably to comparative aircraft, since the air/vehicle will be able to take off and land equal to an area of its transformed footprint.

10.0 Arrive at and exit from a predefined area of 20m (65 feet) diameter (‘location Bravo’)

AirShip Endurance V9

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UAV Deployment Venues. With air/vehicle’s onboard UAV systems and sensors, many deployment venues are possible for “location Bravo.” The aircraft has the capability to deploy in rough terrain, launch from forward operating bases, and maneuver for launch and land from confined spaces no more than 4 meters (13.1 ft) in diameter.

The ability to launch and land the air/vehicle in and from confined spaces allows the deployment of the UAV in critical areas under combat conditions, off ships at sea, and on trucks in transit. No long obstacle-free landing approach is required, such as when other UAVs (e.g., Predator) need a runway or into a capture device (e.g. Tier I VTOL UAVs). When such an approach path is not possible (such as coming over a large fence into a small operating area), the air/vehicle can maneuver for vertical take-off and landing. The aircraft effects lessen the logistics footprint by eliminating the need for launch and recovery equipment.

Confined Space Launch and Landing Requirement. The air/vehicle will be able to take off and land in confined areas without a launch or recovery system or a confined-space launch. From launch, the aircraft transitions by rapidly extending its low-aspect wings to and from a fixed wing mode and flies to a maximum speed up to 300 mph (260 knots). The flexibility achieved through these various flight modes, combines with the high-speed performance and survivability of this VTOL aircraft for unmanned and manned applications.

Using conventional ducted fan rotor assemblies, the air/vehicle is propelled while lateral low aspect wings are extended. At launch, the lateral ducted fans pivot from a range of 0 to 15-degrees as the air/vehicle climbs in altitude. At launch, this diverts thrust to raise the aircraft during rear ducted fan transition from horizontal (0-degrees) to vertical (90-degrees). The thrust produces lift and balance from the two lateral ducted fans. As the two laterals and one rear ducted fan engage, the aircraft begins to move and transition into forward motion that culminates into full fixed-wing flight characteristics.

Each ducted fan assembly has three-bladed double counter rotating rotors used to generate the required lift for hover and low-speed forward flight. The air/vehicle operates all three ducted fans to take off like a helicopter. The aircraft then accelerates to about 35 mph (30 knots) when the lateral canards engage to push the nose up, flaps deploy from the lateral low aspect wings, and rear V-Wing is fully extended. All synchronize to create additional forward lift. Once the air/vehicle is at a sufficient forward velocity, the required lift and velocity transfers from the two lateral pivoting ducted fan turbines to the rear ducted fan turbine. Lateral ducted fan turbines may be dialed down and the lateral low aspect wing flap deployment stabilizes and levels off the aircraft, while moving the rear ducted fan turbine from a horizontal to vertical position with immediate forward thrust. Low aspect wing flaps can be retraced along with the V-Wing. The two lateral wings share the lift loads in the fixed wing flight mode. A reverse of these events and engagement of the lateral ducted fan turbines transition the air/vehicle back to its three ducted fan turbine configuration that enables the VTOL mode for landing on a small footprint.

By using the pivots of the lateral ducted fan assemblies that support full aircraft lift, the air/vehicle eliminates the need for a mechanical drive train and transmission, as well as the need for an anti-torque system. Eliminating these typically heavy, maintenance-intensive systems will greatly reduce aircraft weight, maintenance, complexity, and cost. Because the air/vehicle’s rear ducted fan turbine is transitioning from horizontal to vertical to allow for high-speed forward flight, the rear ducted turbine’s airfoil cross section must be momentarily elliptical. This creates drag, but is a compromise between the optimum airfoil shape for conventional rotor flight and that for high-speed VTOL fixed wing rotor flight.

Multibladed Propeller Fans. AirShip’s ducted fan rotors are multibladed rotors set inside a coaxial duct or cowling, also called a ducted propeller or a shrouded propeller. Although in a shrouded propeller the ring is usually attached to the propeller tips and rotates. The duct serves to protect the fan blades from adjacent objects and to protect objects from the revolving blades, but more importantly, the duct prevents radial flow of the air at the blade tips. Rotor efficiency remains high over a wider speed range with a properly shaped duct than without.

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11.0 Operate in winds of up to 15 knots Flight Control Strategies. In addition to the aircraft design and analysis, development and demonstration of the necessary control strategies for hover, level-flight, and transition regimes are necessary for operating in winds of up to 15 knots. Air/vehicle focuses on robustness to uncertainty, especially with regard to wind, and it allows our air/vehicle controller to define flight operational safety bounds for launch, landing and flight.

Hover Control Strategy. Variable-pitch contra-rotating propellers have historically had mechanical problems. To solve this problem, air/vehicle twists the blades via electro-hydraulics thus delivering a variable-pitch rotor blade. The aircraft uses a separately-controlled electric motor for each rotor post. It also uses single-chip three-axis roll sensors to inform the autopilot. For overall endurance as a function of the percentage of hover duration, the hovering endurance of a rotor twist and taper will be reduced from the value of the hovering endurance. The power required for hovering is increased over that required by a rotor with ideal twist. For example, the air/vehicle rotor with a twist of 12-degrees and no taper will require 2 percent more power to hover than a rotor with ideal twist. Therefore, when invoked, the aircraft’s variable-pitch rotors will have a hovering endurance of 2 percent less than the hovering endurance of a rotor with ideal twist.

Level Flight Control Strategy. For level flight controls, the air/vehicle ducted fan assemblies are twin rotors that spin in opposite directions on a single shaft. The contra-rotating blades cancel out each other's torque effects so the air/vehicle does not need a tail rotor for stability. This makes the aircraft easier and safer to fly at treetop height. Eliminating the need for a vertical tail rotor and an associated drive system also reduces the aircraft's profile in combat maneuvers.

This air/vehicle aircraft is designed to be unusually agile. It turns by changing the pitch angle of its upper and lower rotor blades to different degrees. The more sharply pitched of the two rotors develops more lift and absorbs more power than its counterpart, creating a powerful, immediate instant torque effect that snaps the fuselage around in the direction specified. In some circumstances, such as hovering in a cross-wind, the air/vehicle VTOL is more stable than a conventional helicopter. Our designers exploited the aircraft's unusual flight characteristics to simplify the number of parts required for manufacture and maintenance.

Airframe View

Front Section ViewAerial and Anterior Components View

Augmenting the two forward lateral ducted fan rotor assemblies is an alternative swivel-up (vertical to horizontal) rear ducted bladeless fan rotor assembly or Air Accelerator. This rear turbine provides first vertical launch and land capability and then horizontal to vertical turbine swivel up transition for forward propulsion. This transitions the aircraft’s forward thrust while also enabling the rear turbine power boost for hovering.

Transition Regime Control Strategy. To design the optimal transition regime, we create a simulation to accurately model transition between hover and forward flight states. We support changes in geometric configuration between time steps for rear turbine fan duct angle repositioning relative to the lateral turbine ducts nestled in the fuselage and angle-of-attack. The aircraft is enabled by an autopilot and when simulated, you can read inertial data at each time step which enables geometric views at select power change. Accuracy is

ABSTRACT Only.

achieved by splitting the propulsion model from the aircraft model, verifying data using multiple methods, and validating simulation models with experimental tests.

Robustness to Uncertainty (wind, etc.). Design of the Automatic Flight Control System for the air/vehicle will trigger a robust integrated tri-turbine assembly auto flight adjustment. This enables the aircraft to detect small or large wind shifts so the aircraft self-corrects automatically while counteracting the effects of wind gust uncertainty. The system is invoked for hypersensitivity during vertical takeoffs, during stationary hovering observations over target areas, and during landings. Control strategies will be investigated that utilize accelerometers as sensors to detect wind gusts and automatically initiate counteractions for the Attitude Control feature of the Flight Control System. This feature will stabilize the vehicle against adverse effects of wind gusts. Analyses of the effectiveness of control strategies will be conducted in order to determine known safe bounds for launch and landings. The robustness of the engines and Automatic Attitude Control will serve to stabilize the air/vehicle UAV against the uncertainty of wind gusts, rain and other adverse explosive concussion conditions.

Safe Bounds for Launch and Recovery. The aircraft is capable of taking off and landing vertically from rough terrain, roads, city streets or highways with an unprepared site no larger than its footprint. The aircraft reduces dependence on constructing expensive war zone runways and airports, while providing the flexibility needed in battle zone situations.

12.0 Not exert accelerative forces >5 gn (>59 m/s2) on personnel

This proposal identifies the aircraft design and control strategies necessary to achieve a VTOL UAV (pilotless) hover capability mainly used during launch and land operations. The proposal highlights design trade-offs that yield the capability of a fixed wing UAV (in terms of endurance and payload) while allowing for vertical take-off and landings described below in the various mission cycles without refueling. None of these mission cycle scenarios exert accelerative forces > 5 gn(>59 m/s2) on personnel

The air/vehicle’s key design technologies include adaptive low aspect wing structures, ducted fan rotor propulsion, lightweight composite structures, advanced flight controls for stable transition between vertical and horizontal flight, hybrid fuel to electric powertrain, and an electric motor in-wheel drivetrain for ground transit.

The air/vehicle UAV employs a wide aerodynamic high lift/drag ratio fuselage with twin canards able to engage from the fuselage just forward of the operations cockpit. Lateral integrated low-aspect ratio retractable wings are set mid-range to rear on the aircraft's mid-section. A horizontal empennage wing, with a slight pitch angled rear V-Wing, serves as an angled tail section where two in-set winglets with rudders rise from zero to a 45-degree position. Together, the two tail winglets of the V-Wing serve as stabilizers while the aircraft is in flight. For ground transit, the low aspect wings retract into the fuselage reducing the width of the aircraft to a manageable size for landing and ground transit, while the V-Wing returns to a flat 0-degree position. Two turbine assemblies supporting twin counter rotating ducted fan rotors are on either side of the aircraft and a rear twin counter rotating ducted fan rotor assembly (or alternatively the an air accelerator turbine) helps support this efficient configuration while ensuring aircraft stability.

Lift stability is maintained by the ducted fans during VTOL operation, when absence of horizontal airspeed would normally render control surfaces ineffective. Lateral low aspect wing flaps employ Fowler flaps that slide backwards before hinging downwards, thereby increasing both camber and chord, creating a larger wing surface better tuned for lower speeds leading to the hover state. It also provides some slot effect (or gap) between the flap and the wing enabling high pressure air from below the wing to re-energize the boundary layer over the flap. This helps the airflow to stay attached to the flap,

ABSTRACT Only.

delaying a stall.

The aircraft’s lateral ailerons are hinged flight control surfaces attached to the trailing edge of the low aspect wings and add to the control of the aircraft in a roll. This control surface results in a change in heading due to the tilting of the lift vector. The two ailerons are interconnected to produce a rolling moment about the aircraft's longitudinal axis. A rear tail horizontal aileron serves for additional lift and drag maneuvers.

The exterior fuselage aerodynamic front to the rear quarter panels, slide forward doors, low aspect wings, rear V-Wing and anterior panels are constructed from composites. Smaller external components and the overall airframe is constructed of treated cast aluminum or titanium that is impervious to rust and corrosion and also staunchly resistant to dings and dents. Expectations are for the aircraft’s exterior to hold up against corrosion for an estimated 25 years. The aircraft’s aerodynamic front-end, flexible outer fuselage are designed and manufactured to absorb light impacts. The air/vehicle’s basic structure is formed from a combination of stamped, extruded and cast composites with much of it bonded by high-strength adhesives, along with conventional weld riblets.

Where the fuselage airframe curves intersect, hollow joints allow pieces to be fitted together. This technique creates an extremely stable and rigid internal cargo-payload compartment cell, improving safety. Composites and titanium have a high strength-to-weight ratio, but they are inherently less stiff than steel. Hence, in some of the aircraft’s structure larger cross sections of these materials are required to duplicate the stiffness of a steel structure. This tradeoff undermines some minor weight savings. The air/vehicle UAV’s airframe ends up about 50 percent lighter than alternatives. The composite and titanium can be easily extruded - pushed through a relatively inexpensive die to form lengthy surfaces with complex aerodynamic cross sections.

Slide Forward and Aft Door View 3-Dimensional View Ground Transit View

The Air/vehicle UAV makes use of electronic components, instruments and software for in-flight control and ground transit. The design solution is seen as a UAV-based vertical lift transport aircraft. This novel combination VTOL aircraft is powered by a conventional liquid-fuelled motor that powers on-board generators to supply electric power to Lithium-ion batteries that in turn power electric in-wheel motors for ground transit.

Ground transit is accomplished by electric motors mounted in the wheels at each of the wheel assemblies. This wheel hub motor combination is an electric motor that is incorporated into a hub of the aircraft’s ground wheels and using drive-by-wire controls, allows the operator to drive the air/vehicle in a three or four wheel configuration for ground transit.