XP-40Q-2: test data emerged!

Discussion in 'Aviation' started by tomo pauk, Apr 12, 2013.

  1. tomo pauk

    tomo pauk Creator of Interesting Threads

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    I'm sure that Greg would just love this - I know I do :)
    Mike Williams has posted the flight test data about the XP-40Q-2. The plane made 422 mph, and was able to do ~420mph from 20000-26000 ft. All that on the F-27R engine, up to 3200 rpm and water injection. Mr. Whitney might want to update his book, since he does not states the engine's capabilities with ADI. For climb (= small 'ram'), the power at altitude on 'WER wet' regime was ~1690 HP at 17000 ft, and 1190 HP at 25000 ft.

    The test: here; dated April 5th 1944.

    So we eagerly await for the XP-40Q-3 tests :D
     
  2. Aozora

    Aozora Well-Known Member

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    Interesting, I've just downloaded. Handling was considered to be much improved over the previous P-40s, with a good rate of roll.
     
  3. GregP

    GregP Well-Known Member

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    Thanks for posting that, Tomo. I've often wondered how it performed and now can read about it. I wonder if we could find a flight report on the XP-72 and the Boeing XF8B ... I always thought those two would have been a great 1 - 2 punch, but really don't have much definitive information to go on except reported top speed. Would be nice to see a V-n diagram and some flight performance data.
     
  4. drgondog

    drgondog Well-Known Member

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    I wonder how much degradation of the surface sanding and polishing occurred prior to flight test?
     
  5. johnbr

    johnbr Well-Known Member

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    #5 johnbr, Apr 14, 2013
    Last edited: Apr 14, 2013
    Reading it a sounds like a very good x sport aircraft.Here is 3 way.
     

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  6. GregP

    GregP Well-Known Member

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    I doubt the plane was kept in a hangar, but 2 - 3 months of outside with little washing makes even a carefully-prepped finish a bit rough. Too bad we didn't get a test with the standard factory finish. I'd also like to see the number 3 aircraft test it it ever surfaces.

    Wouldn't it be nice if performance tests were standardized so the data points and test procedures were similar to one another? They don't publish these things, at least for public consumption, for current service aircraft, sio it will be many years before we know if planes like the F-22 and F-35 have standardized test points even today. They certainly SHOULD, and the test points should be adjusted only when the plane being tested exceeds a previous standard boundary.
     
  7. tomo pauk

    tomo pauk Creator of Interesting Threads

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    Lovely 6 view, johnbr :)

    Looking at the climb power graph (small ram) of the V-1710-101, it shows nicely the benefits of the RPM increase, from 3000 ft to 3200. The critical altitude for 'WER wet' (75 in Hg) went from ~9500 ft up to almost 17000 ft - a 7500 ft increase! Cost in power was some 70HP (from 1750HP down to 1680). The crankshaft was still the 6 counterweight type, the future 12 counterweight type was enabling 3200 rpm also in military regime.
    Interestingly enough, the critical altitude for the WER for the late models of single stage V-1710s was also at 9500 ft (no ram). One might wonder how fast would be the P-51A, P-39M/N/Q and P-40M/N while operating on 3200 rpm? The critical altitude for the WER should be notably higher, even if we conservatively limit the gain to, say, 5000 ft.
    Another interesting thought might be the P-63A and P-38 operating on 3200 rpm. The P-38/40/51 might need a new reduction gear, though, in order to not over-speed the prop.
     
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