You asked "What aircraft has survived a 2/7 [don't you mean 5] failure rate?"

Well, the F-14 for one. The prototype crashed on its 2nd flight. The 6th, 8th, and 10th prototypes all crashed, too. Actually, if I'm reading this list correctly, it appears by the bureau numbers that the 1st, 2nd, 6th, 8th, and 10th preproduction prototypes were all lost between 1970 and 1974. Put another way, from 1970 to 1999, some 141 F-14s were lost out of fewer than 700 built for the US Navy.

There were a lot of other famous aircraft that lost their prototypes (sometimes several of them) and went on to have successful careers. Off the top of my head, I can think of the B-17, B-29, P-38, and the P-51.