US Defense Secretary Leon Panetta announced Friday that he is resuming a troubled program to build a short-takeoff and vertical landing variant of the new F-35 fighter.
The F-35B, the most complex and costly of the fighter's three variants, has been beset by development delays and cost overruns.
The setbacks led Panetta's predecessor Robert Gates to announce in January 2011 that he was putting the aircraft on probation for two years, and would cancel the program if its problems were not fixed.
At the Patuxent River Naval Air Station in Maryland, the home of the US Navy's test pilot school, Panetta said "real progress" had been made and the threat weighing on the aircraft's future had been lifted.
