MichaelJP wrote:
I wonder how many found it too much and came to grief - were there any
trainer versions of the P51D or was the first flight always the first solo
as well?


I don't think I've ever seen a trainer P-51, in fact most U.S. WW II
fighter didn't have a trainer version.
I assume that after you had done enough hours in a Texan trainer they
assumed you were ready to take on a Mustang, although I have heard of
some pilots training stateside in P-39s before moving up to P-47s or
P-51s overseas.
(Chuck Yeager for instance)

Pat