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Allied and Soviet Air Forces Please use this forum to discuss the Air Forces of the Western Allies and the Soviet Union. |
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#71
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The figures I have seen show it reaching mach 0.89 when being piloted by sq/ldr Tobin in late 43/early 44. In contrast, US trials of a P-51: "In July 1944 Wright Field test pilots explored the high speed dive characteristics of a Merlin powered Mustang. A series of dive tests were made starting from about 35,000 ft. in a test airplane equipped with a mach meter. The idea was to explore the effects of compressibility such as buffeting, vibration, control force changes, and so on. Initial dives showed the onset of the problem to occur at just under mach .75. Additional dives were made, usiung three test pilots, which carried the aircraft sucessively to mach .77, then .79, and up to mach .81, and finally to mach .83 (605 mph) As the dive mach number was increased the compressibility effects became more violent, but the aircraft wsa still controllable, and it was possible to fly it out of the problem when desired, at mach .83 the shaking and buffeting of the aircraft was so strong that it was decided to explore no further. The airplane had suffered considerable structural damage and was written off." (America's Hundred Thousand) and: Flight Research Branch, tests of P-51D: "The airplane has been dived to a maximum mach number of 0.85, and on several occasions to 0.84. In each case the pilots reported the vibration became extremely heavy beyond 0.80. In each dive to 0.84 or above the vibration becames sosevere that the airplane was damaged. The leading edge skin of a wing flap was buckled between rivets, a coolant line cracked and hydraulic line broken due to vibration on various dives to 0.84 and above. " |
#72
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Only two of the 39 Spitfires on that list were Mk XVI and they belonged to No. 421 Squadron. Because the engines were changed so frequently it is possible that both planes had their Packards replaced with Rolls-Royce Merlins before they crashed. Quote:
No one should be surprised. Here is something you'll never find in Rolls- Royce press releases: In May 1943 (long before Packard-powered Spitfire XVIs were in service), RAF Fighter Command informed the USAAF that on average the Allison engine lasted about three times longer than Merlins in-between bearing failures. They noted the V-1710-39 was routinely overboosted to 72" Hg manifold pressure for up to twenty minutes at a time without damaging the engine. They said that the Allison could get them home even when the bearings were ruined, which is more than they could say for the Merlin. They also told the USAAF that the Merlin did not run efficiently below 1600 rpm and the higher fuel consumption made that engine an undesirable alternative for Tac/R missions. Finally the RAF recommended that the automatic boost controls should be removed from all P-51 airplanes. Quote:
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#73
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This topic has come up often on the Usenet message boards over the past 10 years. Been there, done that. Quote:
I just surveyed 162 Spitfires for engine failures and only nine were Spitfire Mk XVI. And it is not clear if any of these Mk XVIs had the original Merlin 266 installed. Possibly all nine of them had Rolls-Royce replacement engines when they were lost. |
#74
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Except for one plane, the No. 133 Eagle Squadron was wiped out near Brest on 26th September 1942, partly due to the poor leadership of the Englishman who was leading the squadron. It started with the RAF weatherman who failed to predict high winds and the controllers at Exeter who did not keep track of their progress, but then the mission commander Flight Lieutenant E.G. Brettell made several mistakes that one would expect from a novice pilot, not a seasoned veteran. Only Don Gentile escaped because he aborted early. Robert Beaty managed to fly all the way back to the UK, although he ran out of fuel and crashlanded with serious injuries. Quote:
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23rd April 1943 Spitfire XII EN601 of No. 41 Sqn was on a shipping recce to Dieppe when shot down by JG26 but it was claimed as an RAF Mustang I. The South African pilot F/Lt T. R. Poynton was killed. 24th February 1944 Lt. Waldemar Radener of JG 26 claimed to have shot down a P-47 SE of Bonn. But there were no P-47s in the area at the time, and a German researcher discovered his victim was a P-51 flown by Don Rice of the 357th FG, who had shot down Gerhard Loschinski just moments earlier. 15th June 1944 Luftwaffe pilots of JG 2 claimed to have shot down four RAF Mustangs but the only RAF air-to-air combat losses listed this day were three Spitfires from No. 421 (RCAF) Squadron. 29th December 1944 An Fw 190D-9 of JG26 was shot down in error by a Bf 109, probably from JG27. Shit happens. 29th December 1944 In his combat report this day, Fritz Ungar of JG 54 misidentified No. 56 Squadron RAF Tempests as P-47 Thunderbolts. 22nd February 1945 Heinz Gehrke of JG 26 reported he was shot down by a Spitfire near Plantleunne, but his own official casualty report credits his downing to a Tempest at 1745 hrs. This matches the after action report of D.C. Fairbanks (an American) who flew RAF Tempests with No. 274 Squadron. Spitfires, Tempests and Thunderbolts had similar elliptical wing planform shapes so occasionally there was an ID problem. Quote:
Found some relevant comments from LeRoy Gover, who piloted Spitfires with 66 and 133 Squadrons, RAF and later flew Thunderbolts with the 336th Fighter Squadron, USAAF.... " February 21st, 1943 - My P-47 is being painted white on the nose and tail today, so those bastards won't shoot at us. About four of us have been shot at now by Spits, Typhoons and [British] ground defenses because they think we look like FW-190s. I hope it works, because we have enough trouble with the Jerries having to worry about our own guys. March 9th, 1943 - We were fired on by our own coast guns [British] on the way home. I guess the white stripes don't work very well " |
#75
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Hello Six Nifty .50s
thanks for clarification. My impression has been that Spit XVIs were allocated to certain sqns because at least part of the engine tools were different for Packard Merlins from those for RR Merlins. If I'm right it would be illogical to supply RR Merlins to Mk XVI sqns if they were not changing RR Merlins to all of sqn's Spits. But I can be totally in error in this, I freely admit. On the story on Packard machine-tool operators pouring their stale Coke to cutting-oil tanks. I checked that briefly, it is in one of Alec Hexshaw's articles in Aeroplane Monthly (Feb 1984 or 83, father's duties suddenly overrun aviation research this morning) on Merlin reliability problems, mostly on skew-gear failures but he also mentioned this. But it caused sometimes problems in connection rods, not in bearings and usually engine failed at the climb test at latest so it probably did not cause many engine failures in sqns. On S/L Martindale's dive. You think that there was a calibration error in Mach meter, don't You? What You think was the real Mach number S/L Martindale reached in that dive or was generally possible to reach in late marque Spits? I asked this because I'm interested in the max diving speeds of the different WWII fighters. And I have bought the explanation that Spit could dive so fast because it had so thin wings. |
#76
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Also, I have an account of Ottomar Kruse, II/JG26, in which he clearly states that all enemy aircraft were US to them. Quote:
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I have to note here that I have heard several RAF pilots complaining about US abilities to identify own aircraft. |
#77
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AIR 2/7498 - 95A (British archives reference) has correspondence from Air Marshall Tedder, commander RAF forces in the Middle East, asking for more P-40Fs (Packard Merlin engined) rather than P-40Ks (Allison engined), both because of the better performance of the Merlin engined variant, and because they suffered less bearing failures than the Allison engined aircraft. The records also show lower serviceability rates for the Allison engined P-40 variants in North Africa than for the Hurricanes serving there. Quote:
![]() (If the image contravenes any rules, eg size etc, or if images aren't allowed, please tell me so I can remove it) The image is part of a preliminary report on the dive tests (they were still using a Mustang I as well at that point), Martindale's accident came later. Quote:
I do know that later on the RAE (who carried out these tests) wrote to Supermarine saying that the Spitfire was the most suitable aircraft for the tests because it could sustain higher mach speeds than either the P-51 or P-47. Quote:
The information I have seen is that the RAF had to abandon the use of 100/150 fuel, which allowed 25 lbs boost in Merlins, in their Spit XVIs because it was causing problems with the Packard engines. Quote:
The truth is, the types weren't usually mixed and matched, because different spares and tools were required, which would make servicing a nightmare. There's a good reason why they gave a different model number to the Spitfire XVI (which was a Spitfire IX, but with the Packard built engine). It wouldn't make much sense to create a new model, then go and mix the engines up afterwards. Quote:
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#78
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Spitifre XVIs saw some extensive service since late 1944 and comments about them were varied. Complaints about quality, similar to those concerning CBAF Spits back in 1940, were mixed with appreciation in those units, that had a mix of rather clapped Mk IXs dating back to 1942! A mix of variants in one Squadron was theoretically possible and I think differencies were minor for a qualified groundservice, the key was doubtless spares supply and rationalisation of spares stock within a unit. I have to say that I never saw any complaints concerning Packards in Mustangs used to chase V1s but that they worked quite rough. Perhaps no direct comparison to RR Merlins there? |
#79
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You forced me to look up the production numbers, which tell an interesting story.
Out of over 20,000 Spitfires built, almost exactly 1 in 20 was a Spitfire XVI, which of course served for a fairly short time (as Franek points out, some early IXs were serving for years, as were many Spitfire Vs.) So if in 9 Spitfires was a XVI, you'd expect in 9 engine failures to be as well. In fact, if there were 9 engine failures in Mk XVIs, you'd expect 180 in all Spits, and yet Six Nifty .50s says there were only 162, which gives the XVI a slightly higher failure rate than average. Quote:
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#80
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In May 1943 (long before Packard-powered Spitfire XVIs were in service), RAF Fighter Command informed the USAAF that on average the Allison engine lasted about three times longer than Merlins in-between bearing failures.
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OF THE MUSTANG I (P-51) 26th August 1943 HEADQUARTERS NORTHWEST AFRICAN STRATEGIC AIR FORCE CHARLES F. HORN Brigadier General, GSC, Asst Chief of Staff, A-3 The Introduction of the report says it was filed as a result of contact with RAF Wing Commander Peter Dudjeen on 31st May 1943. Quote:
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For the Battle of Britain period, I looked at FIGHTER COMMAND LOSSES by Norman Franks and he listed just a few RAF fighters lost to engine problems between July 1940 and October 1940. But then I checked the BATTLE of BRITAIN: THEN and NOW and found 35 RAF fighters reported lost to engine failure or some type of motor trouble -- not including a few cases that I discounted because they involved glycol leaks or pilot error in handling the fuel switches. I do not live in the UK so I cannot visit their archives whenever I please. I own a few of the published RAF squadron histories. The ones that have an appendix showing a list of airframes is very helpful, but it will take time to find more of these at the local libraries. |