V-22 first flight

To answer the original question: The first of six Full Scale
Development (FSD) Ospreys flew on 19 March, 1989. It was followed by
Ship 2 on 9 August 1989, Ship Four on 21 December, 1989, and Ship 3 on
6 May, 1990. Ship Five rolled on its back on its first flight at the
Boeing plant on 11 June, 1991 when miswired sensors generated false
commands in the fly-by-wire control system. Aircraft Four was lost
with five lives in a crash at Quantico, Virginia on 20 July, 1992.
Aircraft Six was outpaced by changes in the design and never completed.
The FSD aircraft accumulated around 1,100 flight test hours. They were
followed by Engineering and Manufacturing Development birds, and now
Low Rate Initial Production aircraft in different Blocks.