The P-82 was two P-51 Mustangs joined together to form a long-range protective fighter to escort B-29 bombers for the invasion of Japan. Two atomic bombs took care of the invasion plans, but the Army Air Force went ahead with production of the Twin Mustang.
All aspects
of the aircraft were precisely engineered, which is good for things that take
to the air.
“The XP-82 was to be powered by two
Packard-built Rolls-Royce V-1650 Merlin engines. Initially, the left engine was a
V-1650-23 with an additional gear in the propeller reduction box to allow the left propeller to turn opposite
to the right propeller, which was driven by the more conventional V-1650-25.
“In this arrangement both propellers
would turn upward as they approached the center wing, which in theory would
have allowed better single-engine control. This proved not to be the case when the aircraft refused to become airborne
during its first flight attempt.
“After a month of work North American
engineers finally discovered that rotating the propellers to meet in the center
on their upward turn created sufficient drag to cancel out all lift from the
center wing section, one quarter of the aircraft's total wing surface area. The
engines and propellers were then exchanged, with their rotation meeting on the
downward turn, and the problem was fully solved.”
https://en.wikipedia.org/wiki/North_American_F-82_Twin_Mustang
Slide rules
and pencils and paper, combined with aircraft engineering experience, said, “This
is how it will work.” Reality, though, was something else entirely. You have to
wonder, “What was the test pilot’s reaction when the aircraft would not leave
the ground?”
That Murphy character sure likes to pop up when he is least expected, doesn't he? I'll but that pilot did indeed have a rather perplexed expression on his face, but not as perplexed as the engineers.
ReplyDeleteEvery airplane has a takeoff speed, and I would guess the test pilot was surprised when the YP-82 refused to follow written expectations.
ReplyDelete