And now - new stealth jumpjet makes first hover landing
'Cobblestones' effect reduced, says Brit test pilot
Vid Following yesterday's initial hover, the new F-35B Lightning II - world's first supersonic stealth jumpjet - has now made a vertical landing. British test pilot Graham Tomlinson said the aircraft is much easier to set down than today's Harrier.
“Today’s vertical landing onto a 95-foot square pad showed that we have the thrust and the control to maneuver accurately both in free air and in the descent through ground effect,” said Tomlinson, a former RAF Harrier jockey and now lead test pilot for the F-35B. The first three jumpjets are in flight tests at Naval Air Station Patuxent River in Maryland.
The vertical landing was a venture into the unknown for the F-35B, as its design is radically different from the Harrier and it had not previously hovered low enough for surface effects to come into play.
Tomlinson has previously said that the F-35B is easier to handle in the hover than a Harrier: apart from more sophisticated control systems, he says that the forward lift fan, driven by a shaft from the engine and mounted in a vertical tunnel behind the cockpit*, blasts cool air downward as the swivelling jetpipe nozzle at the back of the plane blows fiercely hot jet exhaust.
In the Harrier, hot exhaust roiling up from the ground can get sucked into the jet's engine intakes, causing unpredictable power blips, but Tomlinson has said that the F-35B's fanshaft air acts as a "dam", causing the hot exhaust to stay to the rear and letting the engine operate more consistently. He told reporters that the "cobblestones" felt during a hover landing were "very light" compared to his days flying Harriers.
“The low workload in the cockpit contrasted sharply with legacy short takeoff/vertical landing (STOVL) platforms,” he added.
Tomlinson also gave it as his assessment that data from the landing yesterday indicated the F-35B will be able to make vertical landings still carrying 5,000lb of fuel and weapons. This will mean that it can come in to a hover landing on ships at sea still armed with air-to-air missiles, a vital requirement if the plane is being used as a patrol fighter to protect a fleet.