The Pentagon's F-35 Joint Program Office (JPO) and the US Marine Corps are well into a second set of sea trials for the Lockheed Martin F-35B Joint Strike Fighter. Having completed 17 of 19 days of testing, the USMC and the JPO were set to demonstrate the stealth short take-off and vertical landing (STOVL) jet on board the amphibious assault ship USS Wasp on 28 August, but then fate intervened. Aircraft BF-1, which was set to fly that morning's test, suffered from a malfunctioning engine nacelle cooling fan that had to be fixed before the jet could fly. Meanwhile, BF-5 - the other aircraft deployed to the Wasp - had a problem with its power thermal management system computer the night before, says US Navy Capt Erik Etz, the programme's test and evaluation director for naval F-35 variants.
Etz says the two events interrupted what had been a better than average reliability rate for the F-35 during the shipboard deployment. Until the night of 27 August, the F-35B had 90% sortie completion rate on board the Wasp, he says.
Despite the setback, the F-35B's sea trial period has been remarkably successful, says Capt Michael Kingen, a USMC F-35 test pilot assigned to the VMX-22 operational test squadron but seconded to the JSF test effort. Thus far, pilots have flown 90 short take-offs and made 92 vertical landings on board the Wasp during this detachment. Nineteen of those vertical landing were made at night.
The goal of this second set of sea trials is to expand the operating envelope of the F-35B in preparation for the jet's initial operational capability date in July 2015. The F-35B has been tested to 40kt (74km/h) of headwind and 10kt of tailwind, Kingen says. Particular attention has been paid to landing with starboard crosswinds, where a lot of turbulence originates due to the ship's superstructure, says Lt Col Matt Kelley, a senior USMC F-35 test pilot assigned to the JPO.
Additionally, the F-35B's short take-off capability was tested with its maximum internal weight, Kingen says. Pilots are also determining the jet's minimum short take-off distance, he says. Those trials involve letting the aircraft "settle" toward the sea as it leaves the deck.
Thus far, Kingen says he is pleased with the aircraft's performance during the sea trials. Ironically, BF-1 flew its test sortie shortly after reporters departed the ship.