Hover pit tests completed two days ago moved the first short-takeoff-and-vertical-landing (STOVL) variant of the Lockheed Martin F-35 within days or weeks of its first flight.
A Lockheed spokesman confirms the propulsion system for the STOVL demonstrator – named BF-1 – completed a series of conversions from conventional mode to vertical landing mode.
The tests were conducted at Lockheed’s hover pit, where the aircraft is tethered to the ground on top of a steel grate. The pit allows Lockheed’s engineers to measure vertical thrust generated by the engine.
The hover pit is the last major stop before the first flight event for BF-1, which has been scheduled for late May or early June.
Despite the need to complete hover pit tests before first flight, the lift-fan that helps power the aircraft during STOVL mode will not be engaged in a flight test for several more months. BF-1 will fly in conventional mode throughout the first flight.
Getting the aircraft airborne has wider implications for Lockheed. The US Department of Defense has linked the release of production funding for the first batch of six F-35B low rate initial production (LRIP) aircraft to completing the first flight event.
In addition, BF-1 is the first “weight-optimized” airframe produced after Lockheed re-designed all three variants in 2005 to reduce or offset weight by as much as 2,268kg (5,000lbs).
The F-35B, on order by the US Marine Corps, the UK Royal Air Force and UK Royal Navy, is the first western aircraft to combine supersonic speed with the STOVL capability.