The 97 F 35 aircraft in the US fleet have all been grounded for inspection of the engines after an engine fire an F-35 on takeoff. Lockheed makes the fighter aircraft. The engines are made by Pratt and Whitney...
http://www.reuters.com/...
Link to article on the fire at Eglin Air Force Base in Florida...
http://defensetech.org/...
The F 35 has been plagued by problems for years, from development through testing and after delivery. It is THE costliest warplane in history, cost estimated in 2013 at over $400 billion...
http://www.defenseone.com/...
A short series of developmental problems and a history of sorts of the F 35...
http://topics.nytimes.com/...
And Lockheed Martin's sales blog on the F 35 Lightning II...
http://www.lockheedmartin.com/...
It seems that many in the Pentagon were persuaded we really need this fighter. They kept it in play despite a great number of problems, many with engine fires, cracked engine parts, poor design of the oxygen system and many more bugs. It has evidently not yet been made reliable, although other countries, among them Japan and Israel, are buying them for their own use...Japan may be re-thinking that decision.