The Pentagon began the process of grounding the current fleet of 51 F-35 Joint Strike Fighters late Thursday after routine inspection of a test jet revealed evidence that a low pressure turbine blade in the jet's engine had cracked. The problem was found in the third stage of a Pratt & Whitney-produced F135 engine powering an A-model variant, which is designed for use by the Air Force.
Currently, 34 of the jets are in use at training bases in Florida and Arizona. The rest are involved in test programs. A subset of the fleet (those flown by the Marines) had just been cleared to fly on February 13 after being grounded for nearly one month for another problem. The Marines grounded their version of the jet in January after a problem with a fuel line was discovered prior to a test flight. The engine problem has grounded all versions of the aircraft though no other cracks have yet been reported. The fan blade will now be evaluated at Pratt's Middletown, Conn., facility, where the company will seek a root cause. A report is expected within two weeks. The Joint Strike Fighter is produced by Lockheed Martin. The program's development costs are nearing $400 billion. That figure reportedly marks the jet as the Pentagon's most expensive weapons system. The Joint Strike Fighter program isn't expected to reach full production until 2019, and targets production of more than 2,400 jets by 2040. All of those figures may be affected by fiscal and political considerations. Source: AVweb, Glenn Pew
Gravity always wins!