The Marine Corps version of the Joint Strike Fighter, the F-35B, has completed its first short-take off and vertical landing (STOVL) at night, allowing the program to gather helmet and lighting conditions in dark scenarios, the JSF program office recently said.

The test at Naval Air Station Patuxent River, Md., was to prepare for the second of three planned sea-based evaluation phases for the F-35B. The STOVL capability is designed to give the aircraft the ability to operate off of amphibious assault ships.

“The completion of this test event demonstrates the F-35B is one step closer to delivering a critical capability to the U.S. Marine Corps and F-35B partners in the United Kingdom and Italy,” said Lt. Gen. Chris Bogdan, the program executive officer for F-35 acquisition. “There is plenty of work to be done and progress to be made, but we’re on a solid path forward.”

The F-35B in fall of 2011 completed ship trials in daylight operations aboard the USS Wasp (LSD-1). Two F-35Bs conducted 72 vertical landings and takeoffs aboard the large-deck amphibious ship.

The April 2 nighttime test comes just a few months after the F-35Bs were grounded following the discovery of a faulty fueldraulic line, which lies in the vectoring propulsion system specific to the STOVL version.

It was later determined the poor crimping on the fueldraulic line was behind the problem, the faulty ones were replaces and the F-35B resumed flight operations shortly before the entire fleet, including Air Force F-35A and Navy F-35C versions, were grounded due to a crack found in a turbine blade in February.

That was determined to be an isolated incident and the F-35s were again cleared to fly.

Lockheed Martin [LMT] is the prime contractor for the F-35 program. Pratt & Whitney is the maker of the engines and is a division of United Technologies [UTX]. The fueldraulic lines are supplied by Stratoflex, a unit of Parker Hannifin [PH].