Image of P51 courtesy of Wikimedia
One of the most effective fighter airplanes of the Second World War was the P51 Mustang.
Image of P51 courtesy of
Wikimedia
The propeller of this aircraft had blades of length L = 1.7 m. Like all propellers, this one becomes much less efficient --- and prone to damage -- if the tips of the blades approach the speed of sound (v = 343 m/s).
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