The Defense Advanced Research Projects Agency (DARPA) and Aurora Flight Sciences, which are developing an unmanned, tilt-wing, vertical-takeoff-and-landing experimental airplane (VTOL X-Plane) called LightningStrike, have a achieved a significant milestone by completing flight tests of a subscale vehicle demonstrator (SVD).

The tests, which ended in early March at Webster Outlying Field in Southern Maryland, demonstrated the ability of the 325-pound SVD to fly vertically, tilt its wings and canards to fly horizontally, and then return to vertical flight, DARPA and Aurora announced April 4.

The 20-percent scale model of the Aurora LightningStrike Vertical Take-off and Landing Experimental Plane (VTOL X-Plane) undergoes a flight test in Maryland. Photo: Aurora Flight Sciences.
The 20-percent scale model of the Aurora LightningStrike Vertical Take-off and Landing Experimental Plane (VTOL X-Plane) undergoes a flight test in Maryland. Photo: Aurora Flight Sciences.

The 20-percent scale model flew a total of 10 times over a year “without incident” and validated key technologies that will go into the VTOL X-Plane program’s upcoming full-scale aircraft, said Carl Schaefer Jr., Aurora’s LightningStrike program manager.

The testing was “hugely successful, said Ashish Bagai, program manager for DARPA’s Tactical Technology Office. “The aircraft exhibited exceptional flight characteristics, with no loss in altitude even as it transitioned from vertical to horizontal flight.”

LightningStrike, recently designed the XV-24A, is intended to take off, hover and land like a helicopter; fly fast like a plane; and have more agility and speed than existing helicopter-plane hybrids.

With the SVD tests under its belt, the program has shifted its focus to completing a 12,000-pound full-scale aircraft, such as by building parts and putting tooling and assembly fixtures in place. Manassas, Va.-based Aurora plans to roll out the completed plane by the end of the calendar year.

LightningStrike’s propulsion system will be tested in Indianapolis before being installed on the plane. Unlike the battery-powered SVD, the full-sized LightningStrike will use a Rolls-Royce AE 1107 engine, the same power plant used on the twin-engine V-22 Osprey tilt-rotor aircraft, the U.S. military’s existing manned helicopter-plane hybrid.

The program intends to begin flight testing the full-scale demonstrator in late 2018 at Patuxent River Naval Air Station in Maryland. Testing might eventually move to the West Coast to accommodate high-speed flights. While the SVD is now on display in DARPA’s lobby in Arlington, Va., the program might fly it again to supplement the full-scale plane.