"These contracts demonstrate
the maturity of the F135 engine program, which has completed more
than 100 successful test flights and hover pit testing, meeting the
demanding STOVL vertical thrust requirements."
Source: Warren Boley, vice president,
Pratt & Whitney F135 programs, after the U.S. Department of
Defense has awarded Pratt & Whitney a $571 million production
contract for F135 engines to power the F-35 Lightning II.