While the Defense Advanced Research Projects Agency (DARPA) has set a firm requirement that its Gremlins unmanned air vehicles return to a Lockheed Martin C-130 cargo aircraft, an airship could offer an attractive option for future recoverable drone missions.

That is according to Ronald Hochstetler, an aviation technology specialist focusing on airships at Science Applications International. In a June paper published by the American Institute of Aeronautics and Astronautics, Hochstetler argues for an unmanned lighter-than-air air station carrier concept. One of Gremlins’ most glaring challenges remains the ability to retrieve four UAVs every 30min on the turbulent open ramp of a cargo aircraft. Rather than a C-130 flying at 200kt, a steady airship could operate more like a navy carrier, he says.

“It has its rear squadron on board, sends out its UAS maybe to do surveillance over a beach or check out electromagnetics and interesting signals coming offshore, and you have these birds out there all the time doing different missions,” Hochstetler tells FlightGlobal. “But the airship is kind of there hanging offshore or hanging over land; it’s a flying airbase.”

While the Department of Defense has offered the C-130 and the Boeing B-52 bomber as support aircraft for the Gremlins and arsenal plane mission, Hochstetler says the mismatched speeds of the large aircraft and small UAVs will pose a problem. Unlike airships, the legacy aircraft also need ground maintenance that limits their mission duration, he says.

Hochstetler’s idea is not unprecedented. The US Navy pioneered two flying aircraft carrier concepts in the 1930s: the USS Akron and USS Macon. Each airship could carry 55 tonnes of fuel and 25 tonnes of equipment and crew, he notes. The Macon carried a fleet of five Sparrow Hawk scout planes and could conduct long-range strategic reconnaissance missions for up to three days.

Today, the US could equip existing, commercial airships with experimental gear for investigating launch and recovery and UAS refuelling, he says. An articulated robotic arm could be used to facilitate the recovery process and would allow UAS storage in an internal hangar deck.

“You [could] have team on board and you could explore these areas at very low speeds, 20mph,” he says. “You could probably even come up with an employable existing airship that could launch, operate maybe two to four of these small UASs for long periods of time from the airship itself.”

Source: Flight International