|
Re: P-47 Actions 29 Mar 44 near Berlin
The critical mach number (and hence maximum dive speed) of the Spitfire was higher than its contemporaries because of the thinner wing. Mcrit is a function of the thickness of the wing and how far aft is the point of maximum thickness. Hoerner's classic work on aircraft drag has a figure showing the curve produced from the experimental data on many aircraft. The Spitfire is, if I remember correctly, around 0.91, the Mustang around 0.84. Other aircraft, such as the Me 262, cluster around 0.78-0.82. Which is sufficient in itself to prove that no, the Me262 did not go supersonic. Some aircraft e.g the P-38 encounter compressibility problems at speeds lower than Mcrit because of local interferences, in this case between the fuselage and the nacelles.
A postwar Spitfire PR XIX was timed at a greater rate of descent (than Martindale) in a thunderstorm over the South China Sea: however, I suspect that the air mass itself was descending and thus the local Mach Number no greater.
|