"Boris" wrote in message
ups.com...
Do any readers know what particular plane in World War 2,
was rumored to have broke the sound barrier ?

I might be perhaps unique on the group to answer this question, as I had a
P51D out to .75 during an O2 failure some years back. During the post event
investigation with some friends from North American , this subject came up
several times and was openly discussed.
First of all, no prop fighter ever made it out to mach 1.

I had a friend, Herb Fisher, who did high speed dive testing using various
prop configurations, in a P47 Thunderbolt. Herb didn't find a prop that
would make it through the drag rise between .90 and mach 1. Several types of
prop were tried. All failed. I had another good friend, Erik Shilling, who
flew with Chennault in China, who had his best friend die diving a P40 when
the prop tips went into transonic shock.

The Brits tried it at Boscombe Down with Spits after the war. Same result.
As the prop tips entered critical mach through tangental velocity, the drag
curve became intensive. That, coupled with propeller shock denied all
propeller driven fighters supersonic flight.
As for the jets;

Much has been written pertaining to the early German jets. One German pilot
(Hans Mutke)swore he exceeded mach 1 in the ME262. Investigation revealed he
honestly believed this.
What happened to him was that his aircraft had exceeded the pressure rise in
his pitot system as he was diving and he misread the instruments. US
engineers have absolutely proven that the 262's basic design was not
conducive to supersonic flight, again due to drag rise.
As for my experience in the 51, I had a walking stick, a potential overspeed
condition, and compressibility onset. I barely made it out alive, and I
would never want to do it again :-)
George Welch was the first to go Mach 1 in the prototype F86. Yeager
followed in level flight several days later.
Dudley Henriques