Yes, the 450 ft. wide turn at 400 MPH doesn't seem to add up. Perhaps if it was stretched 2000ft., as the P-51 spun on itself, acting as a giant brake... I think Skychimp posted a misprint or something...
The ability of the Mustang to spin on itself controllably at as it slided (at higher level speeds only) WAS useful to quickly gain something like 90-120° for aiming, and was featured in one episode of History Channel's "Dogfights", where a strangely painted yellow-nose Me-109G-10 was shot down in this way, while the actual pilot who had shot it down described this "special" maneuver, and the lucky shot he got as he sprayed gunfire ahead of him in a semi-circle, as his Mustang "spinned" on itself well over 100°.
I have often heard of Mustangs instantly turning the tables on a pursuer directly behind by GAINING 360° inside ONE 360° turn, which means, to cite several specific combat reports, having double the turn rate of the pursuing Me-109G-6 at speeds of about 250-350 MPH TAS (the Messerschmitt's hole between its two turn peaks).
There are dozens, hundreds, of anecdotes of the Mustang appearing near-invincible at higher speeds, and gaining 360° in less than 30 seconds (over 12° per second !), on a turning enemy.
Though that 450 ft. turn will certainly turn out to be a misprint or an error by Skychimp (It really does seem not to add up...), a fact much easier to demonstrate is that the best turn rate of the P-47 and P-51 WAS at speeds closer to their maximum level speeds than the usually assumed 250-300 MPH range. This is supported by combat anecdotes, and by flying tests done with modern instruments less than 18 years ago...
1990s tests. Quote (from memory); "To our surprise, these two aircraft's (P-47-P-51) best turn rates turned out to be quite a bit closer than expected to their maximum level speed, which implied an inability of these machines to sustain their best turn rate for any lenght of time. The P-51's stall at lower speeds was unforgiving, to the point where prolonged combat would not to be recommended, to avoid speed decreasing to a much lower point, making this more of an interceptor. The P-47 also maneuvered less well at lower speeds, but its stall was much more forgiving."
I'll get those 1990's tests for your perusing...
Gaston.
