Originally posted by Benny Moore
Here's something else interesting.
Now, the same source stated that with maneuver flaps, the P-38 turned as well as the P-63. But that's not all. Look at the Northrop P-61. The Black Widow, without flaps, has a better sustained turn than the P-61, P-47, P-38, and F-4U! The P-61 is roughly the size and weight of a B-25. Now there you have it - weight does not equal turning ability.
Benny, Navy tests indicate that the F4U-1D should slot in between the F6F-5 and P-51D-15 (but much closer to the F6F-5). In addition, the weight he uses for the P-51D is well below normal operational weight. Removing the under-wing pylons and flying with an empty aux fuel tank doesn't even get the weight as low as the one he plugged into his calculation.
Also, the P-61's wing loading is far below that of the P-38L.
P-38L: 53.4 lb per sq/ft
P-61A: 40.7 lb per sq/ft
This is primary reason why the P-61 turns so well for a large fighter.
Back to the various lift coefficients; From NACA Report #829, which is where Dean plucked the number for the F4U from, is data taken in a wind tunnel for an F4U-1
without a propeller. The lift coefficient without the prop is 1.48. With the propeller turning, the lift coefficient goes up to 2.27, the same as the number he used for the F6F. You can download a copy of report #829 from NASA's report server.
Dean does get one thing right though. The relative minimum turn radius can be compared (by proportion only) by dividing wing loading by the lift coefficient, which is why wing loading is a very important factor.
Flaps increase the lift coefficient. Fowlers also increase wing area (about a 15% effective increase in the P-38). However, other aircraft have flaps too. So, the question is, does the increase in both lift coefficient and decrease in wing loading improve the P-38's turn radius enough to out-turn a Bf 109? I don't think so. It may be very close, but the 109 also has flaps, which will increase its lift coefficient too. I believe that in the real world, just like in the game, the most significant factor can be found in the cockpit.
My regards,
Widewing