Originally posted by SgtPappy
BLARG! this is definitely getting nowhere without Widewing - the Silencer. I always have wondered why the P-38's Fowler flaps never could help the large bird outturn the F4U.
The increase in wing chord due to the opening Fowler flaps SHOULD increase a large decrease in the wing loading of the aircraft, causing it to outturn the F4U. Sure, the Hog's flaps could help the a/c turn very well, but the fact that they seem to only direct thrusy downward and out along the wing should give a gentle lift property but NOT such a significant turn radius length reduction since the chord continues to actually shorten when seen from above the wing.
The Fowler flaps, however, would stretch the wing chord out, causing the prop wash to directly move under the 'lengthened' wing chord producing more lift. Why, then do our P-38's, turn sooo poorly when compared to the Spitfire or Mustang - both of which should be completely outturned by the Lightning?
Maybe I'm missing something, but this is what I have learned so far.
There's several reasons why I haven't pitched in here previously. We have some engineers who post here who have solid aeronautical background. I'm a mechanical engineer, and aerodynamics is not my field. A second reason is that there is almost no test data available that defines how good or bad the P-38 turns with flap use. There is a great deal of combat records, but this type of evidence is often laced with perception and not completely reliable as a basis for modeling virtual aircraft. You can see what I mean by just reviewing the discussions on this BBS. We see films posted where a fighter out-turns another and the pilot involved points to this as evidence that his plane is better. More often that not, this only reflects the pilot of the other aircraft and not what he was flying.
We can look at some basic aircraft characteristics and draw some equally basic conclusions.
Roll rate is important because the quicker a fighter rolls, the faster it can change lift vectors. The P-38s have a low rate of roll at low speeds... Too much mass off of the centerline.
Wing loading is a good place to begin when it comes to turn radius. P-38s have a relatively high wing loading when clean. General Kelsey once estimated that the Lockheed type Fowler flaps increased wing area by 11% and effective area by about 15% (due to slipstream effect). In the game, the normal takeoff weight is 17,500 lb. Dividing that by 327.5 sq/ft provides 53.4 lb per sq/ft. Let's increase the wing area by 15%. 17,500/376.6=46.46 lb per sq/ft. Let's compare that to the basic F6F-5. Our Hellcat weighs 12,483 lb. 12,482/334=37.37 lb per sq/ft. So, a P-38J with full tanks has no chance at out-turning a fully gassed up F6F-5.
Let's do another example. A fully fueled Bf 109G-6 weighs 6,940 lb. So, 6,940/173.2=40.07 lb per sq/ft. Once again, the P-38J should not be able to out-turn this fighter. To have any chance, the P-38 must shed a lot of weight. If it loses 2/3 of its internal fuel, its weight drops to 15,860 lb. 15,860/376.6=42.11 lb per sq/ft. Therefore, the P-38J can compete reasonably with fully fueled 109G-6, to the point that pilot skill is a dominant factor. This assumes that the 109G-6 pilot DOES NOT use his own flaps or his plane is in a low-fuel state as well. If either or both cases exist, he gains the advantage again.
Personally, I believe that both the P-38s and P-51s took a major hit when the drag model was revised. I think both types need some FM tweeking, but I feel the P-51 suffered more than the P-38 did (excluding the initial and now corrected P-38 flap bug).
In real life, P-38s were complex fighters, and only the best pilots became masters of the type. Average pilots were constantly struggling with the plane, which is why they had much greater confidence in the P-51. It was just easier to fly.
In Aces High, we have the same issues. P-38s are very capable, but require time to learn and not everyone will be able to exploit the Lightning to its full potential. Those that can and do are quite formidable.
My regards,
Widewing
