YF-16 tests pressure suit

[flateric]

Can anyone give a clue why there was a need to use such SR-71-style pressure suit during YF-16 flight tests? Some extreme altitude tests?

 

[LowObservable]

Probably zoom-climb testing. Joe Bill Dryden, the F-16 test pilot who used to write for Code One and was killed in an accident in 1994 (I think) wrote that one operational pilot had zoom-climbed an F-16 to "way up there" but was in extreme danger without a pressure suit.