"Scubabix" wrote:

This is probably a stupid question, what's the difference between an A-36
and a P-51A?

Dive brakes. The A-36 was the dive-bomber version
of the Allison-engined Mustang.

I'll quote from one of Ernie Pyle's columns, in his
collection "Brave Men" (ch. 12, "Dive Bombers,"
describing life in the 12th Air Support Command
in Italy):

"Our dive bombers were known as A-36 Invaders.
Actually they were nothing more than the famous P-51
equipped with diving brakes. For a long time they
didn't have any name at all, and then one day in Sicily
one of the pilots said, 'Why don't we call them
Invaders, since we're invading?'"

and

"Those boys dived about eight thousand feet before
dropping their bombs. Without brakes their speed in
such a dive would ordinarily build up to around seven
hundred miles an hour, but the brakes held them down
to around 390. The brakes were nothing but metal
flaps in the form of griddles about two feet long and
eight or ten inches high. They lay flat on the wings
during ordinary flying."

and

"If you ever heard a dive bombing by our A-36 Invader
planes you'd never forget it. Even in normal flight that
plane made a sort of screaming noise; when this was
multiplied manifold by the velocity of the dive the wail
could be heard for miles From the ground it sounded
as though they were coming directly down on us. It was
a horrifying thing.

"The German Stuka could never touch the A-36 for sheer
frightfulness of sound. Also, the Stuka always dived at an
angle. But those Invaders came literally straight down. If
a man looked up and saw one above him, he couldn't tell
where it was headed. It could strike anywhere within a
mile on any side of him. That's the reason it spread its terror
so wide."

--Bill Thompson