The defense research agency DARPA recently selected six companies to participate in a year-long program to transform a Humvee-like vehicle into an aircraft. Lockheed Martin and AAI Corporation are asked to supply something that can “avoid traditional and asymmetrical threats while avoiding road obstructions,”
The program hopes to "combine the advantages of ground vehicles with helicopters." But is this scenario even plausible? As John Grossmann wrote for us in January 1996 ("Auto Pilots"), "The challenges of building are perhaps exceeded only by the challenges of selling it. Because a vehicle worthy of both land and air has compromise written all over it, the technical challenges are numerous. The common elements are few: fuel tank, steering wheel, passenger and baggage compartments, wheels, and engine. For flight you need wings, ailerons, a horizontal stabilizer, a vertical tail, rudder, elevators, and a propeller, none of which has any business on a car. For the road, you need a drive train and bumpers, not to mention rear-view mirrors and catalytic converters—all dead weight in the air." (Even Terrafugia's "roadable aircraft" lists this as a caveat: "Terrafugia's philosophy is to design a vehicle for pilots that brings additional ground capability to an airplane instead of attempting to make a car fly.")
DARPA's vehicle is supposed to carry four troops and travel up to 250 miles (that's both on land and in the air). First phase development will include propulsion systems, wing structures, and the advanced flight control system.
The flight control system, by the way, will allow for semi-autonomous flight, according to the press release, "permitting a nonpilot to perform VTOLs , transition into forward flight, and update the flight path in response to changing mission requirements or threats."
Did no one think of the Aerocar (left) as a solution to this problem? If I saw a bunch of Marines piling out of that bad boy, I'd run.