It may not be long before we see UAVs that can vertically take-off and land into the battle field. The Defense Advanced Research Projects Agency (DARPA) has come one step closer to its long-standing goal of creating an unmanned vertical take-off and landing (VTOL) aircraft.
DARPA has awarded the second phase of its design contract to Aurora Flight Sciences. The projects aim is to integrate the advantages of a helicopter with the best features of a fixed wing aircraft.
The program, which is called VTOL Experimental Plane (VTOL X-Plane), if successful, would create an aircraft that will possibly fly at unprecedented speeds and distances, have the ability to hover when needed, and carry out varying missions of different complexities — all of this without having to prepare a landing site.
Ashish Bagai, DARPA program manager, said in a statement:
“Just when we thought it had all been done before, the Aurora team found room for invention — truly new elements of engineering and technology that show enormous promise for demonstration on actual flight vehicles.
“This is an extremely novel approach, it will be very challenging to demonstrate, but it has the potential to move the technology needle the farthest and provide some of the greatest spinoff opportunities for other vertical flight and aviation products.”
DARPAs requirements for the VTOL X-Plane are:
- Achieve a top sustained flight speed of 300 kt to 400 kt (345 to 460 miles per hour)
- Raise the aircraft hover efficiency from 60 percent to at least 75 percent
- Present a more favorable cruise lift-to-drag ratio of at least 10, up from 5-6
- Carry a useful load of at least 40 percent of the vehicle’s projected gross weight of 10,000-12,000 pounds
Aurora’s Phase 2 design for VTOL X-Plane foresees the unmanned aircraft having two large rear wings and two smaller front canards (short winglets mounted near the nose of the aircraft).
The engine will be a turbo-shaft that is used in V-22 Osprey tiltrotor aircraft. It will be mounted in the fuselage, providing 3 megawatts (4,000 horsepower) of electrical power, making it equivalent to an average commercial wind turbine.
It will be driving 24 ducted fans, of which nine will be integrated into each wing and three inside each canard. The wings and the canards rotate to give direct fan thrust as needed (rearward for forward flight, downward for hovering, and at angles during transition between the two).
Aurora’s unique design is only possible through advances in technology over the past 60 years, in fields such as air vehicle and aeromechanics design and testing, adaptive and reconfigurable control systems, and highly integrated designs. It would also be impossible with the classical mechanical drive systems used in today’s vertical lift aircraft, Bagai said.
Bagai explained that:
“This VTOL X-plane won’t be in volume production in the next few years but is important for the future capabilities it could enable.
“Imagine electric aircraft that are more quiet, fuel-efficient and adaptable and are capable of runway-independent operations. We want to open up whole new design and mission spaces freed from prior constraints, and enable new VTOL aircraft systems and subsystems.”
The program has the goal of performing flight tests in the 2018 time-frame.