Back on topic, is the anomalous F4U Vne allowed in Aces High going to be addressed?
I'm not so sure the top speed performance "issue" has been proven incorrect yet? I suspect you may be correct, but nobody has actually posted any fact-based data to support that argument, unless I'm just not seeing it.
First of all, I don't think it pays to focus on the Vne, because that's essentially a warning but not a line that if crossed guarantees issues. It's almost definitely a somewhat conservative number, so what we'd need to do is find the speed "line" that if crossed guarantees a problem. Vne will be fairly close to that line, but not actually "at" that line. Vne is like the warning under an SUV's sunscreen that says not to exceed 85mph. What happens if you surpass 85mph in an SUV? Are the results always "guaranteed"? Do they depend on the condition of that specific vehicle (i.e. my tires have 37K miles on them, and the front right tire pressure's a bit high, while the left rear tire pressure's a bit low, and there's a chip in my windscreen). Do the results of exceeding that speed depend on the skill (and or fatigue level) of the driver? Does it matter if the vehicle exceeds that speed "on the flat", versus going downhill, versus going uphill?
I think the "critical" speed we need to determine is probably more along the lines of what the "critical mach" speed is for the actual plane. I know the test version of the F4U-1 had a wind tunnel "proven" critical mach of around .73, but that it was estimated to be higher than that in real life; maybe more along the lines of .78. Online, I'm finding that it may be similar to the P51? But lower than the P47 (late-variant P47's anyway)? I wouldn't say that I've found factual data though; probably just more along the lines of an educated guess...
What speed is ".73 mach" anyway? How does that speed vary at differing altitudes and air densities? What altitude/density was the actual plane tested in? How is that density reflected in AH?
And I wonder if the CM was the same for all variants of the F4U or not? I haven't been able to find that info; I'm also having trouble locating an actual Vne, for that matter. It's not listed in my copy of the POH, and I cannot find it in any of the test reports I've gone through.
Second, we need to determine what exactly happens flight-wise when the plane gets close to the CM? Is it recoverable, or not? Would it have been damaged, or not? (i.e. 90% certain the tail surfaces would have been shredded, or that it would not have been possible for the pilot to pull out, damage or not...). Factual info, rather than assumptions. Some reports I read made mention of the bulging fabric on the wings at speed, but they also made mention that the pilot would have been better off "tightening" the fabric? I'm not even sure how they'd do that, to be honest; it's the first I've ever seen that. But it raises the point of the specific condition of the specific plane being tested... Was it "pristine", or "less than pristine". Was it in a condition that would give results likely to be close to the results expected from a plane in better (or at least average) condition? Or was it a worn out wreck that was available for testing because it was no longer a viable combat craft? Many of the test reports I've read sound like the latter, rather than the former. Interesting for sure, but maybe not indicative of a "normal" condition plane? AH models "new" planes (rather than worn out carcasses), so that's the data we need to see replicated.
Third, we need to see what the AH plane does in as nearly identical tests as possible, to determine the same results above for the actual plane. Then we can compare them and argue for a change (if needed). Without that info though, we're just having an interesting discussion, with no chance of proving anything (let alone arguing that a change is necessary).
Shy of that, maybe someone like Brooke with his higher math skills and aero-knowledge can assist with some calculations that would give us "close", "probable" results without actual test data?
In addition, we may easily find that if there is an issue, it may be much more prevalent than just the F4U... How about the P47, P51, P38, 190, 109, etc... Do they behave correctly in a dive? Do ANY of the AH planes? Do they ALL? How have we determined that the F4U is the black sheep of the bunch?
I haven't even seen any film of the AH F4U behaving badly, and that's about as easy to get as can be... I'd get it myself, but my joystick and pedals are in a closet behind a Christmas tree atm...
Based on the Corsair MkII test below, the problem may not be with the critical mach speed, but rather that it's too easy to get the AH corsair to dive fast? But then again, they mention trim... In AH, the trim will automatically dial in a bunch of "down" if you dive, so the game is easily doing what is stated to be more difficult in RL... We'd almost need to toss the test results out if they're trim-related, because the AH CT solves that problem for us?
