The Boeing Joint Strike Fighter short-takeoff-and-vertical-landing (STOVL) aircraft, the X-32B, yesterday accomplished a major aerospace milestone when it transitioned from wingborne flight to a hover.
During the aircraft’s 44th flight, Dennis O’Donoghue, Boeing lead STOVL test pilot, transitioned from fully wingborne (conventional) to jetborne (STOVL) flight mode and then decelerated the X-32B to a steady hover 200 feet above the ground. The ex-Harrier pilot then accelerated out of the hover and transitioned back to conventional flight before making a ‘slow landing.’
During four other flights the same day, the X-32B completed three additional hovers and numerous transitions to STOVL flight, demonstrating the aircraft’s robustness as well as the reliability of its direct lift system.
In total, the aircraft hovered for eight minutes yesterday, the single longest sustained hover covering two minutes and 42 seconds.
‘The plane was extremely stable during hover,’ said O’Donoghue. ‘I was very impressed with the X-32B’s controllability, responsiveness and the ease of moving into and out of the hover.’
He added that the first hover was a significant milestone in preparation for the first vertical landing. ‘During hover testing, we establish the flying qualities and hover performance of the vehicle – a necessary step before proceeding to vertical landing.’
‘The other important aspect of this milestone is the fact that our direct-lift system has demonstrated such a high degree of simplicity and reliability that the transitions from conventional to STOVL mode and back again have really become routine. For the pilot the transitions are effortless, which is definitely what you look for in a STOVL fighter.’
Boeing has now completed more than 50 percent of the X-32B’s scheduled flight-test requirements since the aircraft’s first flight in March.
Leading up to the first hover, the X-32B flew as many as five times in one day, demonstrating in-flight transitions as well as slow landings down to 60 knots. The plane is expected to soon complete its first vertical landing.
The X-32B’s first flight in March marked the aircraft’s entry into a four-month test program to validate the Boeing direct-lift approach to the STOVL requirements for the US Marine Corps and the UK Royal Navy and Royal Air Force.