Apparently the £100,000,000 jet crashed into the sea because someone forgot to remove a £10 plastic rain cover.
Nothing in the F-35 program is as cheap as £10. Normal remove before flight tags can be bought for £10 each, but F-35 ones will have a few extra zeros on them.
Story goes that the engine intake blanks are often removed and used as "knee pads / cushions" when ground crew crawl into the engine intakes to check the front of the engine (which happens regularly). If the ground crew then forget to remove the "knee pads / cushions" as they crawl back out again, then this is what happens. I'm told you can't actually see very far up the intakes from outside, so if the "knee pads / cushions" get left in there, the pilot can't see them when he does his pre-flight walk around checks.
Someone will be in really hot water for leaking the video of the crash :
https://www.youtube.com/watch?v=LFoyICk0qJcThe remaining 5 RAF/RN F-35's flew off the carrier this morning and returned to RAF Marham.