A Virginia-based start-up company has announced setting a new endurance record with a 56h flight by a combustion-powered unmanned air vehicle (UAV) funded by the US military.
The flight by the Vanilla Aircraft VA001, registered as N204HR, opens a new ultra-long-endurance capability for aircraft in the in the 50-500kg (110-1,100lb) weight class, which roughly spans the UAVs sized between the Boeing/Insitu Integrator and the General Atomics Aeronautical Systems Predator A.
Vanilla Aircraft has not published specifications for the VA001, but a video posted on the firm’s web site shows an aircraft perhaps slightly larger than the AAA RQ-7 Shadow. It is launched by sitting in a wheeled cradled, which is towed down a runway with a long cable attached to a pick-up truck. As the aircraft reaches flight speed, the VA001 jettisons the cable and starts a two-bladed, pusher-propeller mounted on the tail. Lacking a landing gear, the UAV is recovered by skidding on its belly to a stop on a runway.
Elements of propulsion system are also described in a series of documents available online. The company’s press release announcing the record endurance flight discloses the fuel type as JP-8. One of the funding agencies, the Defense Advanced Research Projects Agency, also announced the flight in a separate news release, describing the vehicle as powered by a diesel engine. The company’s aircraft registration filed with the US Federal Aviation Administration lists the engine as a “four-cycle” type.
The VA001 is designed to remain aloft for 10 days without refueling. The record endurance mission was planned as a five-day flight, but it was cut short due to weather, Vanilla Aircraft says. But the company notes the UAV landed with enough JP-8 fuel to support an additional 90h in the air, or a more than 6-day mission.
"This effort represents tremendous and unprecedented coordination among civil, defense, academic, and private industry to bring a heretofore only imagined capability to reality," said Vanilla Aircraft CEO Timothy Healy, a retired Navy rear admiral.
The VA001 is designed to carry 13.5kg payload, but flew with 9.07kg of actual and simulated systems, which included a communications relay and a multi-spectral imaging sensor.
“We could fill a wide cost and payload-capability market gap between small electric and large military unmanned aircraft, which is perfect for many commercial applications," says co-founder and programme manager Jeremy Novara.