Shortround6
Major General
Thank you for the correction.
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Until yesterday I had read the same as you and posted same, even reading my last post it is not completely clear whether 2 aircraft went to Calais and Gravelines or 2 went to Calais and another 2 went to Gravelines, that would be the 4 that I had previously read about. The two places are only about 10 miles apart but that coast was heavily defended.Thank you for the correction.
Green does seem to have great responsibility for the myth of the P-39 as mostly a ground attack aircraft, in 'Russia' it was used as an air superiority fighter.
Uh, a 90 Imp. gallon tank IS a 110gal American tank.AND still less than what the Lightning and Thunderbolt was able to provide. Can we also add the Spitfire with a drop tank in for good measure? I read that there were 90 Imperial gallon auxiliary tanks available and actually used on occasion but not sure if they could be jettisoned or not. Anyone with more concise information on this please fill free to chime in....
Thank you so much for your post.I thought I'd try and add something potentially more useful to this thread than my previous Witisism. It has been a most interesting thread, though it's been expanding at a pace that makes me worry i may have missed a few posts along the way. I hope I don't by accident have overlooked something too important. I could never aspire to improve on most of the many informative details that have been under close scrutiny, my efforts are more directed at the greater picture.
I indeed was introduced to the P-39, and many other ww2 planes, by Green - and Swanboroughs - publications on aircraft, I am not sure that Green is too dismissive of the P-39, his assessment of the Ki-43 seem more unfair. In any event, I always felt that the P-39, on paper, looked quite good, especially compared to the P-40. Though the latter was based on a far earlier design, I do think that comparing this aircraft to the P-39 is the fairest that can be done to a contemporary allied aircraft, a little more on this later.
However, to begin 'on thread' (in as far as this isn't the how much superior to any other pane in any mission was the P-39?), I'd site the comparison (fly off) between a P-39D-1 Vs 'The Aleutian Zero', the recovered A6M2 Zero 21. My source is Mikesh, Robert C: 'Zero fighter' Zokeisha Publications 1981 p26f.. It is a picture book, and while I am pretty sure the report referred to (originally from december 1942) is to be found somewhere on this forum, I didn't manage to dig it up, so here goes from the selection in the book:
"takeoff was accomplished in formation on signal to initiate a climb from sea level to 5.000 feet indicated. The P-39D-1 was drawing 3000 rpm and and 70 inches manifold pressure on take off when the engine started to detonate, so manifold pressure was reduced to 52 inches. The airacobra left the ground first and arrived at 5.000 feet indicated just as the zero was passing 4.000 feet indicated. This manifold pressure of 52 inches could be maintained to 4.500 feet indicated. At 5.000 feet from a cruising speed of 230 mph (200 kts) indicated, the P-39 had a marked acceleration away from the Zero. Climb from 5.000 to 10.000 feet at the respective best climbing speeds, (thus eliminating zoom effect) the P-39 reached 10.000 feet approximately six seconds before the Zero.At 10.000 feet indicated, from a crusing speed of 220 mph (191 kts) indicated, the airacobra still accelerated away from the Zero rapidly. Climbing from 10.000 feet to 15.000 feet, both aircrafts maintained equal rates of climb to 12.500 feet. Above this altitude the Zero walked away from the P-39.
Climb from 15.000 to 20.000 feet indicated, the Zero took immidiate advantage and left the Airacobra. The climb from 20.000 feet to 25.000 feet was not completed as the P-39 was running low on fuel.
On a straight climb to altitude rom take off under the same conditions as before, the Airacobra maintained the advantage of the climb until reaching 14.800 feet indicated. Above this altitude the P-39 was left behind reaching 25.000 feet indicated approximately 5 minutes behind the Zero. At 25.000 feet from a cruising speed of 180 mph (156 kts) indicated, the Zero accelerated away from the P-39 for three ship lengths. This lead was maintained by the Zero for one and a half minutes and it took the P-39D-1 another thirty seconds to gain a lead of one ships length."
The comment on the fly off against a P-40F is: "These tests were not completed with the P-40F because it was found impossible to obtain maximum engine operation." To return to an aircraft with the Allison, the early P-51 tested compared worse to the Zero in climb, but better in speed, at least up to the 15.000 feet above which "[t]he P-51's power plant failed to operate properly". Finally it could be remarked that the P-38F had the engines function properly all up to 30.000 feet.
Pity that the Japanese in '42 didn't oblige to the P-39 by coming in at low level. In any event most aircraft still climbing when meeting an escorted raid will be at a distinct disadvantage, but I am not sure whether this example is comparable to the Spitfires problems at Darwin. In any event the P-39 does seem a decent performer down low. Whatever the seriousness of its deficiencies in handling, they did not stop the US itself from operating the type for at least a couple of years, but of course there was a war on. The Soviets (and probably not just Stalin) seem to have really liked the P-39.
Somebody said a few hundred posts ago that it was a niche fighter (not a typo for nice btw) so i can't take credit for that. However I will remark that the eastern front was a pretty big niche, it was hardly a side show. I've expressed my interest in the P-39 in eastern Europe before, in the thread 'How much did Soviet aero-production depend on leand-lease?" Greyman kindly, in post 22, supplied a link that I am not sure i can paste from there. It was most informative, alas also showing some methodological problems, or are we to believe that they shot down no less than 3 He 113? ( Just to be safe: No we're not). Anyway really detailed and reliable data on these operations may never be available. But indeed the Soviets preferred it to the P-40, making it possible that it in some respects not only surpassed this on paper. For these deliberations I'm leaving out the 'Merlin' engined P-40's.
Green does seem to have great responsibility for the myth of the P-39 as mostly a ground attack aircraft, in 'Russia' it was used as an air superiority fighter. Probably too much can be made of specialization in the Red Airforce, as many fighters were equipped for carrying small bombs; however it did possess one of ww2's few dedicated ground attack aircraft in unsurpassed numbers, and apart from the Il-2 several others, including Bostons. So even if the P-40 was a better bomb truck than the P-39, this may have mattered less for Soviet doctrine than Western, making them focus more on effectiveness as a pure fighter, also, as have been remarked, a cannon and two 12,7 weren't as bad in Soviet context. The cannon was useful still for strafing, of course 4 additional light guns were good here too. However, apart from different ballistic properties, 3 kinds of ammo for one fighter does seem a relatively large strain on logistics. Finally, in a P-40 comparison, both aircraft were in the USSR previously unknown properties, in any event making a process of familiarization necessary. Whether they were really considered better than the best Soviet types is another matter, at least after the introduction of Yak-3 and La-5fn.
Ironically The USSR itself had an early plane that failed though it looks good on paper, the MiG-3. It was simply optimized for the wrong altitude, though I have the impression it had numerous other serious issues, I just never came across really detailed and trustworthy accounts of what they were.
Well, just thought I'd sneak in a post while everybody are busy shooting at P-39.
P-39 of Soviet VVS were used for ground(and sea) attacks quite intensively in 1945 and occasionally in 1944. Probably Crimean offensive was the first experience. Whether it was done due to total air superiority and lack of air targets or due to deficit of strike a/c in particular area, it is hard to say. That question was debated for long on some Russian language forums.
Years ago I read interesting materials about P-39s used against German shipping in Danzig Bay in March/April 1945. Over 300 attacks with FAB-250 bombs in about 10 days of operation. Meager results though.
When you try to disprove field results with lab results the most likely cause is someone fiddling the lab results. Complaints about the actual performance of the P-39 in service being below quoted test results were common. It is as likely that Bell were tweaking the planes sent for test as it was that operators were being unkind or weaseling out of contracts.The Green/Swanborough books are unkind to the P-39, especially the N. Their speed and climb numbers are well below the official govt/military tests. But their numbers on other planes sometimes hit the test mark, often not. Same with most reference books. Lots of information, lots doesn't match up. That has contributed to the bad P-39 history.
.View attachment 487986 View attachment 487987
It is as likely that Bell were tweaking the planes sent for test as it was that operators were being unkind or weaselling out of contracts.
A better translation would be Triumph motorcycles. When the T160 was given to the press hacks to test, the engine was straight out of the race shop. It was "tested" as doing 127MPH while those actually sold did 110-115, I knew two guys who got them..Hmmm...so Bell is a direct translation for Volkswagen in American English?
I know...I'll get my coat!
Uh, a 90 Imp. gallon tank IS a 110gal American tank.
Thank you so much for your post.
The Green/Swanborough books are unkind to the P-39, especially the N. Their speed and climb numbers are well below the official govt/military tests. But their numbers on other planes sometimes hit the test mark, often not. Same with most reference books. Lots of information, lots doesn't match up. That has contributed to the bad P-39 history.
The test with the Aleutian Zero was with a P-39D-1. The report was dated December '42 and I believe the actual tests were in Oct/Nov. The P-39D-1 was the heaviest and one of the oldest P-39s to that date. There were much better P-39s available and the vastly improved N model would be produced from November. Probably used the D-1 because it was stationed there. The D-1 was also used in tests against the Thunderbolt and Lightning too when much better versions of the P-39 were available.
P-39N and Q were definitely effective in Russia with 3 of the top 4 Russian aces and scores of 20+ victory aces.
For reference I have attached the govt/military performance charts for the FW190A6 which as we all know is much superior to the Zero in performance with my penciled in P-39N performance. As you can see it was about the same speed above 6km (20000') but climbed substantially better at all altitudes. Standard FW190 vs. standard P-39N from the govt charts.View attachment 487986 View attachment 487987
Uh, 90 gal tank for a Spitfire.Uh, a 90 Imp. gallon tank IS a 110gal American tank.
There were many sizes of slipper tank, some could be dropped but normally weren't, even though they caused a decrease in performance. The issue is not loading up a plane with as much fuel as possible because that doesn't increase range. The Spitfire could have a rear tank fitted, but that changed CoG and like the P 51 had to be burned off first. Fuel could be put in the leading edges 33 Imp. gal. A Spitfire was flown with two 80 imp gal drop tanks and 45 gal rear tank. BUT since you burn off the rear tank first, then the 160 gallons in the drop tanks you only have 85gal (internal fuel) +33 gal(wing edges). to fight 15 mins and then fly home the distance that you just used 205 gals to get to.By the way, 90 Imperial gallons equates to approximately 108 US gallons, not 110. It may seem that I'm splitting hairs here but there actually were 108 AND 110 US gallon tanks employed by the AAF during the Second World War. The first was paper and the latter was metal.
This is a 90 Imperial gallon "slipper" tank used by Spitfires:
I see I was beaten to it.