The US Defense Advanced Research Projects Agency (DARPA) is to terminate its Walrus programme to demonstrate technology for a huge airlifter. Walrus was to have used a combination of aerodynamic lift, gas buoyancy and thrust vectoring to carry loads up to 500t “from fort to fight”. Lockheed Martin and Worldwide Aeros will complete Phase 1 study contracts awarded last year. DARPA, meanwhile, plans to launch a programme to demonstrate a heavylift short/vertical take-off and landing aircraft capable of carrying 20t payload 750km (400nm) at 200kt (370km/h).