ORIGINAL: el cid again
Is there any reason to believe that any particular plane is rated incorrectly in a relative sense? We set out to improve relative plane to plane ratings. Pretty clearly we have done that. How much farther can we go - at what cost in time? I think we have spent far too much time on the P-38 issue in the past - and are once more sucked into it here. But since we are sucked into it - lets get it right. Is there any problem with these new ratings? Any problem at all with any of them which is RELATIVELY wrong for P-38 vs other models - if so what - and to what degree? And how do we know that?
The only reason this is taking so much time is that you insist on ignoring the historical comparisons made in actual testing. Below is the post I referred to. At the bottom of this post I take the area in bold and break it out point by point.
ORIGINAL: Dili
Maneuverability: The subject aircraft was flown in mock combat against P-39D, P-40F, P-47C-1, and P-51 types of aircraft and the following results were obtained:
(a)
The subject aircraft could outclimb all other types used in the test.
(b)
The P-47C-1 was faster at all altitudes, and the P-40F and F-51 were faster up to fifteen-thousand (15,000) feet. The P-39D was considerably slower.
(c)
Against the P-39D, P-51, and the P-40F, the P-38F had a longer radius of turn below twelve-thousand (12,000) feet. From twelve-thousand (12,000) feet to approximately fifteen-thousand (15,000) feet, the radius was almost the same, and from fifteen-thousand (15,000) feet on up, the P-38F had a equal or shorter radius of turn. In the initial turn, due to the slowness of aileron roll of the P-38F, the other types could roll into a turn faster and close up the circle rapidly before the P-38F would reach its maximum radius of turn. It would then take the P-38F sometime, if ever, to overcome this initial disadvantage. The P-38F’s best maneuver against all types tested was to climb rapidly out of range and then turn and commence the combat from a superior altitude. Once gaining this altitude it should retain it, making passes and climbing again rapidly. Knowledge of the local enemy fighter performance will dictate the tactics to be used by the P-38F in the combat zone. It is doubtful if this aircraft will meet in combat any type of enemy aircraft in which close-in fighting will be its best offensive action.
(5)
Ceiling: The operational ceiling was approximately thirty-thousand (30,000) feet and the service ceiling approximately thirty-eight-thousand (38,000) feet, due to engine coolant and carburetor air temperatures becoming excessive.
http://www.wwiiaircraftperformance.org/ ... rials.html
Now how to use this? :
The maintenance difficulties experienced were greater than with any other standard type of American fighter.
The subject aircraft is easy to fly. However, a longer period of time will be required for a pilot to become familiar with the operations and maximum performances of the aircraft than is required for a normal single engine fighter.
Breakdown
Against the P-39D, P-51, and the P-40F, the P-38F had:
1) a longer radius of turn below twelve-thousand (12,000) feet.
2) From twelve-thousand (12,000) feet to approximately fifteen-thousand (15,000) feet, the radius was almost the same,
3) and from fifteen-thousand (15,000) feet on up, the P-38F had a equal or shorter radius of turn.
4) In the initial turn, due to the slowness of aileron roll of the P-38F, the other types could roll into a turn faster and close up the circle rapidly before the P-38F would reach its maximum radius of turn. It would then take the P-38F sometime, if ever, to overcome this initial disadvantage.
Analysis
Conclusion A) The P-38F should have a moderately lower maneuver rating than the P-39D, P-51, and P-40F.
Justification A) Characteristics 1), 2), and 3) were overall approximately equal between the P-38F model and the other aircraft. Characteristic 4) favors the other aircraft over the P-38F. Overall the P-38F was at a meaningful disadvantage to the other aircraft, in spite of having good overall MVR. Hence, the P-38F should be rated moderately lower in MVR than the other aircraft.
Conclusion B) The P-38L should have a slightly lower maneuver rating as the P-39D, P-51, and P-40F.
Justification B) Building on Conclusion A) and Justification A) - the P-38L model had powered control surfaces and hence did not suffer from the disadvantage noted in 4). As a result, we are left with results cited in 1), 2), and 3). It has been noted previously that air to air combat between fighters often winds up favoring lower altitudes. This being the case, slightly more weight is given to 1), resulting in a conclusion that the P-38L model MVR should be slightly lower than the other aircraft.
Sid,
This is my analysis of the historical evidence presented. If the pure formula is giving different results, then the formula is failing for a radically different configuration such as the P-38. We do not need to adjust the formula, we simply need to adjust the MVR ratings so they are in line with the historical evidence. No additional wasted time, just make a best-evidence estimate and be done with it.
The evidence tells us how the planes actually performed. Calculations must yield to evidence. If it were otherwise then bumblebees would have been prohibited from flying until only a few years ago when people finally figured out how they do it.
