GregP
Major
Saw a post (forget the exact one ... was something like "Fw 190: The Roots of the Great Roll Rate" or something to that effect) and it had a chart of the rolling performance of various WWII fighters, mostly ETO with the Japanese Zero included. The speed went from 160 mph to 390mph and there were chart lines showing the rolling performance.
The thread pretty much ended with that chart.
The chart was Table 47 from NACA Report No. 868 and I dutifully put it into Excel to start a rolling model and then decided to get the whole report to see which model Fw 190 and Zero were used for the tests.
Turns out the entire chart was done in an NACA wind tunnel using pb/2V values obtainable at 10,000 feet with a 50-pound stick side force. No real aircraft were used in generating the chart, just wind tunnel models ... so I doubt seriously the chart is correct for real-life aircraft since I, myself, can put more than a 50-pound side force on a P-51 stick (using both hands), and most combats in the ETO were not at 10,000 feet or the P-39 and P-40 would have been right there as great fighters even without the turbos. The P-51 also has three possible deflections for the ailerons, settable by the crew chief, as has been pointed out in the past in here.
Moral of the story is if you take a chart out of context, you don't really know what you are seeing! Caveat Emptor ... or something like that. If you google NACA Report No. 868, you can download your own copy and check it out.
I'd still like to see comparative roll charts of real planes measured in actual flight with real pilots flying them! Oh yeah ... throw in a Bf 109 for completeness since it is conspicuous by its absence in an otherwise mostly ETO aircraft grouping, except for the "Zero".
I believe the report was dated 1947, but the snippet I can get as a pdf was undated and started on page 125 or so.
Cheers.
The thread pretty much ended with that chart.
The chart was Table 47 from NACA Report No. 868 and I dutifully put it into Excel to start a rolling model and then decided to get the whole report to see which model Fw 190 and Zero were used for the tests.
Turns out the entire chart was done in an NACA wind tunnel using pb/2V values obtainable at 10,000 feet with a 50-pound stick side force. No real aircraft were used in generating the chart, just wind tunnel models ... so I doubt seriously the chart is correct for real-life aircraft since I, myself, can put more than a 50-pound side force on a P-51 stick (using both hands), and most combats in the ETO were not at 10,000 feet or the P-39 and P-40 would have been right there as great fighters even without the turbos. The P-51 also has three possible deflections for the ailerons, settable by the crew chief, as has been pointed out in the past in here.
Moral of the story is if you take a chart out of context, you don't really know what you are seeing! Caveat Emptor ... or something like that. If you google NACA Report No. 868, you can download your own copy and check it out.
I'd still like to see comparative roll charts of real planes measured in actual flight with real pilots flying them! Oh yeah ... throw in a Bf 109 for completeness since it is conspicuous by its absence in an otherwise mostly ETO aircraft grouping, except for the "Zero".
I believe the report was dated 1947, but the snippet I can get as a pdf was undated and started on page 125 or so.
Cheers.
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