No, you are speaking of a rarer Mustang III with a very rare engine/boost combination,
Hardly rare. I believe the majority of British Mustangs were Mustang IIIs with -7 engines. But it's besides the point.
The point that I was replying to was how the speed of the Mustang compared with similar power to the 109. It wouldn't matter if this was the only Mustang that ever ran at this power to work out comparitive efficency.
It was also cleaned up, and we all know the Mustang (and Tempest)series was more effected than other planes by uneven wing surface, as it prevented true laminar flow which was the key to the extremely good drag characteristics of the wing at increasing Mach numbers. Cleaning up, for example, a Spit`s wing would yield a lot less speed gain than on the Mustang l.flow wings, as was actually shown in the tests you refer to.
I don't get your point here. Cleaning up this particular Mustang, from a very poor condition, resulted in a 12mph gain. Are you suggesting that cleaning up other planes in a similar condition would yield far less improvement?
The three planes tested were a Mustang, Spit XIV, Tempest V. The Tempest was in the best condition (paintwork "fairly poor", to quote the test), and gained 5.5mph from improved surface finish, the Spit 8.5mph ("poor condition"), the Mustang the worst ("very poor") and gained 12 mph.
The fact that the Mustang gained 12 mph from "very poor condition", and the Spit 5.5 mph from "fairly poor" shows these were not the sort of special tuning you, or Niklas, are trying to suggest.
According to Niklas, an Emil could gain 28 mph from improving the surface finish. What sort of speed would you get out of this Mustang if you improved the finish to that extent?
The core is, the laminar flow wing on the Mustang was a theory, and not a practice, as to maintain laminar flow a perfect surface would be required, which wasn`t achieved even on brand new planes that just left the factory, not to mention under operational conditions.
And wasn't achieved on this Mustang either, otherwise you would have seen a more dramatic increase after the clean-up. I mean, no ammount of polishing would make a Spit XIV wing laminar flow, so we know that the Spit's gain of 8.5 mph from improving the surface finish from "poor" didn't result in laminar flow. So improving the Mustang's from "very poor", getting a 12 mph speed gain, hardly seems out of the norm.
No doubt that the single V-1 chaser variant you always like to pull out was faster and more efficient in turning HP into airspeed than the K, while convinently forgetting about the much more important Mustang D series, which were equal in that at best, however again one not should forget that this is hardly representative to the whole Mustang series.
Isegrim, what are the details of the 109K4 speed tests? How many aircraft, what condition, corrected for temperature etc?
I have already posted the numbers for the Mustang IV from the TK xxx series that was tested by the Brits just as well.
Well, that aircraft was also received from squadron, and was not even painted, it was pure bare metal, with the standard racks.
Can we have some details on this test? Condition of aircraft, what was fitted, wether the results were corrected for standard atmosphere etc?
354 mph at 67" (~1630 HP), and 379 mph on 81" (~1940 HP). Hardly any better per HP than the K-4, that reached the same top speed on the same HP (378mph / ~1960 HP),.
So a Mustang, in unkown condition, taken from an operational squadron, was the same speed as the factory data for the 109K4? We can all guess what condition the 109K4 was, even if it was an actual test, and not calculations.
Once again, Isegrim, you trying to compare different standards. Factory figures for the 109, aircraft pulled from squadron in unknown condition for the Mustang.
On the other hand, I believe the mechanic was truthful :-) If I'd be a pilot whose mechanic invested hours and hours of work to polish my crate to a perfect finish, I'd tell him the aircraft gained 40 km/h even if it were only 10! ;-)
True, encouraging the people you work with is always a good idea, in almost any field.
By the way, in one week Willy Reschke was shot down twice, wrecking a perfectly polished Messerschmitt each time. After that, he had to fly rough aircraft because the mechanics didn't like to invest so much work in planes with such a short lifespan :-)
Do you have any idea what the typical condition of German aircraft used in flight tests was? Normal factory finish, better than normal finish, or used aircraft taken from service units? Any info on the particular tests or calculations for the K4? (the ones Isegrim uses in his speed and climb charts)
