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The British gave up their P-39s because they were inferior to what they were operating at the time, and did not meet promised performance requirements.You could stand some research too. The Brits did need aircraft badly but not a low altitude fighter so they passed them on to the Russians who did need them. They preferred the Cobra to the Spitfire and the Mustang and even their LA-5 and LA-7. In spite of that the British later bought the low altidude, Allison powered Mustang. They did evaluate the P-39 and found it to out perform the current Spitfire Mk V below about 14,000 ft.
I never dismissed the Cobras from the 1946 air races, in fact they were the best prepared and modified aircraft in the lot, although they had big bucks backing them up! I clearly showed what was modified on the aircraft, this indicated in the book "The Air Racer" by Mendenhall.You dismiss the Cobras 1946-47 National Air Race performance where it had minimum airframe mods and mainly a horsepower boost equal to the Mustangs it was running against. A Merlin in the Cobra would likely have given a boost close to the original Mustang, Much of the later Spitfire and Mustang performance boost came from higher fuel octane allowing higher manifold pressure. That helped everyone except the P-39. It never got the engine improvements, just 1200 h.p..
Is this "20 hours" based on what you read in Pokryshkin's book or another source? As I posted yesterday, another Soviet Ace N. Golodnikov stated;One more point that is missing is the Russians operated the Cobra at full throttle, not the book 42 "mp. The engine lasted about 20 hours but they had spare engines on lend-lease or damaged aircraft.
Pokryshkin said "you would have to be crazy to run it at less power".
I almost succumbed to the dark side.Too bad the Brits rejected it after they found that It would out perform their Spitfire V down low, even out turn it. If they had put the same Merlin in it that was used in the first Mustang what would it have been? I think it would have equaled the 1946 US National Air Race champion!
Some of the issues around the P-39 were covered here, its always great to have new angles on it though.You could stand some research too. The Brits did need aircraft badly but not a low altitude fighter so they passed them on to the Russians who did need them. They preferred the Cobra to the Spitfire and the Mustang and even their LA-5 and LA-7. In spite of that the British later bought the low altidude, Allison powered Mustang. They did evaluate the P-39 and found it to out perform the current Spitfire Mk V below about 14,000 ft. You dismiss the Cobras 1946-47 National Air Race performance where it had minimum airframe mods and mainly a horsepower boost equal to the Mustangs it was running against. A Merlin in the Cobra would likely have given a boost close to the original Mustang, Much of the later Spitfire and Mustang performance boost came from higher fuel octane allowing higher manifold pressure. That helped everyone except the P-39. It never got the engine improvements, just 1200 h.p..
That is all true, but the RAF would have operated the Mustang Mk I as it was until the end of the war, in the role of tactical recon, a small but important niche it was the best. The P-39 was not "let down" by its engine, it just want very good and was too late in the game by a country mile.I recall reading somewhere - do not know where - that an NACA engineer was given the job of improving the V-1710. He complained bitterly, "What's the use of trying to improve this piece of junk?"
In reality, the simple addition of a second speed for the supercharger - like everyone else did for their engines - would have helped the altitude performance of the Mustang Mk 1, P-39, P-40, P-51A and A-36A. As it was, setting the supercharger for only one gear ratio was like trying to drive a car only in 2nd gear. And, by the way, only the A-36A was optimized for "low altitude", with max performance at 5,000 ft; the rest were set up for about 15,000 ft and the P-51A for 20,000 ft. Admittedly, then Allison would have needed to build a second model of rear accessory case rather than using the same one for everything.
Adding a Stanley Hooker style liquid intercooler/aftercooler and second stage of supercharging would have made the V-1710 fully competitive with the two stage Merlins. For the P-63 and F-82, Allison added an auxiliary stage supercharger in its own case, coupled to the starter drive, but with no intercooler. The F-82 almost had to be abandoned because the engine would not work well.
If that NACA feather merchant had been the least bit enthusiastic about his job, the V-1710 could have been as good as anything else. I guess maybe he was P.O.ed over not getting to work on jets.
The Spits could not keep up at the speed and rage the A-36 had.
I agree - the USAAC issued the X-609 Proposal in February '37, barely over a year prior to the April '38 date that keeps popping up.Attached is a technical paper I wrote about the P-39 & P-63 a while back.
One of the biggest points of contention regarding the P-39 is the year of the first flight. I personally believe Birch Matthew's research, supported by USAAC documents, which says 1939. Most other publications echo one another and say 1938.
The trouble is, the error keeps getting repeated and the Wikipedia czars use that as a preponderance of evidence.I agree - the USAAC issued the X-609 Proposal in February '37, barely over a year prior to the April '38 date that keeps popping up.
Or the P-38 Expert!If your research contradicts the prevailing wisdom, you must be wrong. Just ask Galileo.
If your research contradicts the prevailing wisdom, you must be wrong. Just ask Galileo.