The P-51D arrived in April of 1944 IN NUMBERS. June would be mid 1944. So you should be comparing the F4U-4 to the P-51D, and not the P-51B which arrived in Europe in the Fall of 1943. The range for the P-38J is listed wrong. By late June and early July the P-38L was replacing many P-38Js in Europe. By August, those still flying the P-38 were almost exclusively flying the L model. The J model was actually a short production run.
The rated combat radius of the P-38J and P-38L, not to mention the P-51D, was well over 600 nautical miles. Again, had the P-47 actually held a range advantage over the P-38, they'd have used it for long range escort in Europe along with the early P-38s. The P-47 could not get past the German frontier. Only in February of 1944 did the P-47 have the ability to go deep into Germany, and that was AFTER they added some internal fuel capacity AND the 128 gallon drop tanks. Your chart would have us believe the P-47 on internal fuel held a 150 mile combat radius advantage over the P-38J on internal fuel and that SIMPLY WAS NOT TRUE. If it was, why did the 8th AF send 50 P-38s to Germany when they had 700 P-47s that according to your chart could fly 150 miles further on internal fuel???????? In fact, the P-38G and H models had a total of 110 gallons LESS internal fuel capacity than the J models and THEY STILL flew further than the P-47 did in late 1943 and early 1944.
No matter what formula you use for figuring range, it won't make a plane with LESS range suddenly have 33% MORE range.
Your chart is more than a little generous towards the F4U-4 don't you think? They'd have you believe that the F4U-4 (critical altitude of 16,500 feet per your chart)still outclimbs the P-38J (critical altitude of 22,000 feet) by 80 feet per minute 3,500 feet past its critical climb altitude. The altitude for the F4U-4 engine is rated is 16,000 feet, the altitude for the rating on the P-38J is 25,000 feet. So 3,500 feet past critical climb rating and 4,000 feet past its engine rating altitude and at the critical climb altitude of the P-38J and BELOW the engine rated altitude the F4U-4 STILL outclimbs the P-38J? That sounds just a little strange, doesn't it. Also note that by 16,500 feet, the F4U-4 has already lost 230HP, and at 25,000 feet the P-38J still has all 3200HP. That's a zero HP loss for the P-38 at an altitude 8,500 feet past where the F4U-4 has already lost 230HP, and the F4U-4 still has 3,500 more feet to climb to get to 20,000 feet, supposedly STILL outclimbing a plane that won't lose ANY HP for another 5,000 feet. You can bet by 20,000 feet the F4U-4 is down ANOTHER 320HP (at least, the rest of the non turbocharged radials are rated at 1900HP at 20,000 feet, I'm giving the F4U-4 an extra 200HP and figuring it at 2100HP), and the P-38J still has all 3200HP, but the F4U-4 STILL outclimbs the P-38J at 20,000 feet? And that's giving the F4U-4 the benefit of the doubt, saying it WON'T lose power as fast at altitude as the other F4U, the F6F, or the other radials. The P-47 doesn't lose power because it, like the P-38J, has a turbocharger, and maintains its full sea level power rating to well in excess of 28,000 feet.
And according to the numbers in your chart, at the weight and power levels given, at 16,000 feet, the P-38 has 5.12 pounds per HP, and the F4U-4 has 5.14 pounds per HP. As altitude increases, the F4U-4 will only get worse, and the P-38 will remain the same up to 28,000 feet. In fact, at 20,000 feet, the F4U-4 will be at about 5.9 pounds per HP, giving it the benefit of the doubt and saying it will be 200HP better than the other radials without turbochargers, but still WELL below the P-38 and losing power fast. The power to weight theory only works IF you maintain the power, and the F4U-4 cannot. Also, the P-38 applies its power through two props, which is a lesser power load per prop, with less losses to prop speed and drag.
Oh, and they include the XF8F and the F7F too, definately NOT contemporaries of the P-38J, the P-51B, nor the P-47D, and NOT mid 1944 combat aircraft. And the F4U-4, using the same basic engine as the F6F5, the XF8F, the P-47D and the F4U-1, is running at a different (higher) power setting than ANY of the other planes with the same basic engine. This negates an actual comparison of "apples to apples". The F4U-4 is being tested between 6 and 11 inches more manifold pressure than any of those planes using the same basic engine. Exactly how is that a true comparison?
By the way, I DO NOT dispute the fact that the radial in the F4U could run at 70". It can. Republic ran one at well over 100" for 24 hours straight with no failure. I'm saying you can't compare one plane with more MAP than it was rated for against other planes at their rated MAP. And yes, MAP ratings were often ignored in combat, as were RPM ratings. I know that. But if you want to test at useable ratings outside those accepted by the USN and USAAF, you can pour some 150 octane in the P-38L (both available in June 1944) and get close to 2000HP out of EACH of the F30 engines at 70" MAP. Rate them BOTH (the P-38 and the F4U) at 70" MAP and the P-38 has a power to weight rating of 4.14 pounds per HP, while the F4U-4 has a rating of 4.78 pounds per HP. And remember, the P-38 won't lose a single HP until it hits 28,000 feet.
Also, according to Art Heiden, Stan Richardson Jr., Jack Ilfrey, Robin Olds, John Lowell, and others, compression in a dive was not even a factor below 20,000 feet. The proper procedure for a dive in a P-38 above 25,000 feet is to pull the engines to idle, drop the dive flaps, and go for it. Why everyone gets hung up on diving and compression when they talk about the P-38 is beyond me. It is a fighter plane it is not a dive bomber. The P-38 does not encounter any serious compression problems below 25,000 feet, and certainly below 20,000 feet, if you drop the dive flaps, set the throttles to idle, and especially if you gently roll the plane. And that is according to BOTH test pilots like Burcham, Levier, Mattern, and Meyer, AND actual combat fighter pilots including those listed above. The AH compression model is porked in that regard. The P-38 will compress at damned near sea level, and that just doesn't wash. The air has to be thin enough to generate compression and make it a factor, and it isn't at sea level. Compression is NOT JUST a shock/pressure wave, but also a pressure differential.
The additional power missing from the P-38L doesn't JUST give higher terminal velocity. It gives a better climb rate, better acceleration from cruise speed, and a better ability to retain speed and energy. Diving is NOT the primay move in combat. Whether the loss of top speed in the P-38L in its current iteration of AH modeling is due to lack of power or due to increased drag, the resulting loss in climb, acceleration, and speed/energy retention is the real issue.
Note, I gave the power rating of the F30 P-38L engine as 1725HP, 3000RPM, 60"MAP, 28,700 feet.
My chart lists .68 Mach as being 504MPH, no altitude given. That's sea level of course.
I'm not at all knocking the F4U, it is in fact probably my second or third favorite plane. I find it equal in many aspects to the P-47, and better than the P-51. It and the P-47 are tied for a close second to the P-38. I dearly love the F4U.
Uh, Hazed, I never said the P-38K SHOULD be in AH. I've always said it should NOT, unless there was an arena for prototypes.
When the P-38K was tested, in February-April of 1943, there were no planes capable of the altitude, range, service ceiling, rate of climb, or top speed that the P-38K had, certainly not in the Allied inventory. The P-38K SHOULD have entered service in August of 1943. There certainly were no Me262s, no P-80s, and no Gloster Meteors operating in August of 1943 in combat. The P-51B had not even entered service in any significant numbers when the P-38K was being tested, and the P-51D was TWELVE months away. Lockheed had intended to replace the J with the K before the J ever even saw production. We're not talking about 1945 here, not even 1944, but 1943! In fact, the performance data is from EARLY 1943. So your theory that the P-38K would have been outclassed before it even got into service, and been phased out in favor of jets in six or 12 months is completely without merit.
I never said the P-38L was rated at METO and all other planes were rated at WEP. I said the WEP is wrong, and is actually the METO setting. The reason I say this is that METO power on the P-38J is listed as WEP on the P-38L, and no METO power rating is given. There is a setting missing in the chart on the later model. The highest rating on the latest model is the same as the second highest rating on the early model. You figure it out.
Oh, and regarding your theory on a typo Hazed, it doesn't wash. First, METO and WEP are not similar enough to be "accidentally transposed", and second, one of the throttle settings for the P-38L would be missing, either WEP or METO. And again, why would the P-38L be slower than the J, even if it only had the same power rating? If the P-38J top speed was 421MPH in WEP, why would the P-38L only go 414MPH? Why is there one setting missing in the ratings of the P-38L? Either the METO is missing for the P-38L (and is LOWER than the P-38J if the WEP of the P-38L is the same as METO on the P-38J), or the WEP is missing for the P-38L and the METO is for some reason relabeled as WEP.
By the way, posting charts etc. from copyrighted material with out express written consent of the author, credit given or not, is illegal. I've already had some posts pulled on other boards for that. I'll post charts if and when I get permission.
