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Tomsk

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About Tomsk

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  1. I'm happy to do that, could you tell me how to enable the G-Limiter I haven't seen that option. I think this is the key: there basically is no data about the areas of high-speed elevator effectiveness or energy bleed. Everything anyone posts is at best a guess: you could be right and everything could in fact match the real world situation perfectly .. or I could be right and it could be there is a bug in the FM. I am perfectly happy to accept the posibility that I could be wrong, and that to some extent I am guessing ... but then so is everyone else. That is all I really meant.
  2. I have not stated the P-47D must be wrong. I've been very clear, that it is hard to know for sure. I have made the case that I think that it is wrong, and have given my reasons why, but I do not claim infallibility. Without hard data, of which this is very little in this area .. it seems impossible to be certain. As I asked before, could you suggest a test that I could do to verify high-speed elevator effectiveness or high-speed energy bleed that could be verified against known test data? It seems to me there is no data, and we are all scrabbling around in the dark trying to make our best estimates with the limited information available: a fact which I am very happy to admit to. As I say, I have no issues with the roll rate it seems fair enough. It's the elevator effectiveness that seems most lacking. The only thing that talks about that is the pilots manual .. and it is pretty vague. Is there hard quantitive data available that could be used to check the maximum G that can be produced at various airspeeds?
  3. I have no complaints about the roll speed, seems reasonable enough: a bit weak at low speeds, pretty good at high-speeds but not in the league of the P-51 or FW-190. It's really the elevator effectiveness that seems off for the high-speed regime, is there any quantitive data available on that? On top of the that the much bigger issue in my opinion is the energy bleed, is there data for that?
  4. I'm not sure why I bother It always goes the same .. you point out that you think there is possibly some flaw in one of the FMs based on your experience. You provide data to support that hypothesis. Some people agree straight out, but also lot of people jump on and post either lots of irrelevant things .. or somewhat tenuous explanations for why it must be correct as is. Rather than saying "hmm yeah that's interesting, could be, really we need more data" people get quite defensive: that what is there must definitely be correct, because obviously bugs never happen in software. Then eventually at some point later the devs patch it and the problem is fixed .. seen it so many times. You're right, it could be that the P-47 is fine and the P-38 is over performing .. it could be that somehow everything is correct as is. But maybe, just maybe, there actually is a problem with the P-47 flight model .. that the many people who report the same issue (energy retention, high-speed handling) are actually not making it all up .. right?
  5. I'd like to do a test focused on high-performance maneuverability: specifically energy bleed in high-speed maneuvers and maximum G that could be produced at various airspeeds. What test would you recommend that I could verify against existing real life test data? I ask because to my knowledge, there is no real-life data about these aspects of flight for the P-47.
  6. The P-38 (261 kg/m^2) has a higher wing loading than the P-47 (207 kg/m^2) ... Perhaps, but that's still a very large difference to explain. The P-38 is not renowned for it's awesome acceleration. In any case I stand by my claims, now with solid data to back them up: The P-47 does not handle well at high-speeds: unlike the P-51, P-38 or even the Spitfire it cannot pull enough G to reach the blackout limit at 400mph. The P-47 bleeds energy faster than any other comparable plane in high-speed maneuvers: even planes that are heavier, with higher wing loading, pulling more G. It is not like this in any other simulation: only in IL2:GB. It's possible that this is all entirely explainable, and makes perfect sense but to my mind this seems enough evidence to warrant some investigation by the dev team: it certainly is very odd. This could indeed be correct, but it could also easily just be a simple bug.
  7. So I've added the P-38. The P-38 is significantly heavier and larger than the P-47, yet it can pull more Gs (it reaches the blackout limit no problem) but it loses signiciantly less airspeed than the P-47. If a heavier plane loses more speed, why does the P-38, pulling much more G (same speed, less time to complete the circle, more G force), have less airspeed loss? So if I recall correctly, the Spitfire had fabric covered elevators until the Mk 21. This source agrees: Mk IX elevators were fabric covered. Fabric covered elevators were prone to balooning and were much less effective than the metal covered elevators of the P-51 or P-47. There are references that support the claim of the Spitfire having heavy control surfaces at high speeds (The Decisive Duel: Spitfire vs 109). I forgot to mention: all planes were trimmed to hold 400 mph for consistency.
  8. So here are some data points I just collected in the sim to compare high speed handling. The test was quite simple: Start at 9000 ft. Go full power, dive down (about 30 degrees) until we reach 400 mph. This generally happens around 5000ft. Then roll 90 degrees to the right (timer starts when roll is finished). Pull as hard as possible in a level turn (no altitude change), without stalling the plane or blacking out. Complete a 360 circle, this is estimated using an easily visible landmark. Timer stops when 360 circle is complete, measure finishing speed and time. All speeds and times measured using tacview. Three separate runs were taken for each plane (R1, R2 & R3) and averages made. Start time: time when the 360 circle started, as shown in tacview. Start CAS: speed (in CAS) when the 360 circle started, as shown in tacview. End Time: time when the 360 circle was finished, as shown in tacview. End CAS: speed (in CAS) when the 360 circle was finished, as show in tacview. Time (s): the time to complete the 360 circle, end time - start time. Delta Speed: the speed loss doing the 360 circle, end CAS - start CAS. === P-51 ==================== Full power, 50% fuel. Start time Start CAS (mph) End Time End CAS (mph) Time (s) Delta Speed (mph) R1: 0:05 412 0:19 270 14 142 R2: 0:29 413 0:45 267 16 146 R3: 0:35 412 0:50 283 15 129 Average: 15 139 NOTES: P-51 is G limited here, easy to blackout at any point all the way round. === P-47 ==================== Full power, 50% fuel, cowl flaps closed. Start time Start CAS (mph) End Time End CAS (mph) Time (s) Delta Speed (mph) R1: 0:33 408 0:51 231 18 177 R2: 0:00 409 0:17 221 17 188 R3: 0:06 417 0:23 233 17 184 Average: 17.3 183 NOTES: P-47 can't pull enough G to blackout at this speed, P-47 also loses so much speed that it stalls before completing the turn. === P-38 ==================== Full power, 50% fuel, cowl flaps closed. Start time Start CAS (mph) End Time End CAS (mph) Time (s) Delta Speed (mph) R1: 0:28 412 0:43 251 15 161 R2: 0:35 411 0:50 255 15 156 R3: 0:25 408 0:41 247 16 161 Average: 15 159.3 NOTES: P-38 is G limited, it can easily reach blackout. === Spitfire Mk IX ========== Full power, 50% fuel. Start time Start CAS (mph) End Time End CAS (mph) Time (s) Delta Speed (mph) R1: 0:29 406 0:46 271 17 135 R2: 0:30 406 0:48 285 18 121 R3: 0:27 413 0:45 295 18 118 Average: 17.6 125 NOTES: very very easy to blackout here, have to be very gentle with the stick and ride the blackout. === Bf 109 G-14 ========== Full power, 50% fuel. Start time Start CAS (mph) End Time End CAS (mph) Time (s) Delta Speed (mph) R1: 0:23 407 0:41 285 18 122 R2: 0:23 404 0:39 280 16 124 R3: 0:29 409 0:45 281 16 128 Average: 16.7 124.7 NOTES: more elevator limited than G limited. === Bf 110 G-2 ========== Full power, 50% fuel. Start time Start CAS (mph) End Time End CAS (mph) Time (s) Delta Speed (mph) R1: 0:02 402 0:23 281 21 121 R2: 0:33 403 0:53 281 20 122 R3: 0:31 403 0:51 291 20 111 Average: 20.3 118 NOTES: strongly elevator limited rather than G limited. Conclusions: The P-51 and P-47 both have G suits (other planes do not) which increases the G tollerance for the plane. However, the P-47 cannot pull enough G to blackout at this speed meaning it is elevator limited and cannot make use of the G suit. As a result the P-47 turns no better than the other planes. This supports my observation the P-47 is not handling well at high-speed, it cannot pull enough G to reach the blackout limit at 400mph, unlike the P-51 (or even the Spitfire) which easily can. This is not in keeping with the many reports of the P-47 having strong and responsive controls at high speed. The P-47 has much much larger energy loss than all the other planes, even though it is turning no quicker. This strongly supports my original observation: the P-47 bleeds energy much worse than every other plane even though it is turning no quicker and pulling no more G. It is the only plane tested to lose so much speed that it tends to stall during the last part of the turn. The data for the P-38 is included. The P-38 is easily able to reach the blackout limit and completes the circle in the same time as the P-51 (G limited). However, despite the P-38 being heavier and larger than the P-47, and pulling significantly more G than it, it loses less airspeed than the P-47. The Spitfire is strongly overperforming: it can easily pull more than enough G to quickly black out, far more than any other plane. This is despite the Spitfire being well known for having heavy and unresponsive controls at very high speeds. The 109 in comparison (a plane that is structurally similar) is elevator limited: you cannot pull enough G to blackout in the 109 at this speed.
  9. So my argument is the P-47 is bad at boom and zoom in IL2:GB, I don't argue it is slightly worse than the P-51: I argue that it is a lot worse. If it was slightly worse I wouldn't complain, I'd expect the P-51 to be a little bit better as well, the P-51 is an amazing plane (my favourite actually). Indeed I've also tried using the Spitfire Mk V and Mk IX to BnZ, and they are also much better at it than the P-47 which is really odd. Right and this is exactly my assessment. It's not slightly worse than other IL2:GB planes, it is just flat bad and it's very weird. As SAS_Storebror says: you get one or maybe two passes, that's it, then you are basically co-E. No other plane is like that. It's also really bad at high-speeds: it locks up hard and is very stiff. It's exactly the same as trying to use high-speed tactics in a 109, which is plane known to be totally unsuited to high-speed maneuvers. People are perfectly free to ignore my assessment, I have no evidence for it, there really can be none. But as someone who flies this style all of the time (focused on high-speed maneuvers), with a lot of practice at it in many different airframes, my view is the P-47 seems really off at the moment.
  10. Thanks, that's interesting, I haven't really tried the P-47 up that high yet, will have to give it a go some time.
  11. People are really good at getting distracted ... I have never made any claims about the dive or zoom capabilities of the P-47. My claim is that the high-speed maneuvering is off, specifically energy retention in high speed maneuvering and overall high-speed handling. No one has posted documents supporting that it is correct in IL2:GB as is, because there are none. High-speed maneuvering capability and energy retention are difficult to measure and are somewhat of a subjective quality: there really is no data. I cannot prove this is wrong for the P-47 in IL2:GB, but I can say with some certainty it is noticeably worse than other similar planes that specialized in the BnZ style, and that it is worse than the P-47 in other simulations. My reason for posting this in the first place was not to get into a flame war about evidence or lack thereof. Rather it is a qualitative assessment: to my eye the P-47 is performing really badly in this role at the moment, and I think this is surprising given the history of the plane. I was looking for feedback from other people who are experienced with flying in a boom-and-zoom style to see if they have the same assessment. Fortunately it's quite easy to tell who is posting on the basis of experience having flown this style extensively, and who is not.
  12. Thanks that's very interesting. I guess it's hard to know what really happened in the past but to my reading of this Johnson is talking about a rolling scissors rather than a simple aileron roll: This sounds like a rolling scissors defence: high-speed rolling scissors involves ailerons, elevators and rudders and is more about overall high-speed maneuverability than straight degrees per second of roll. It's a tactic I've used defensively a lot in the FW-190, P-51 and P-47 which all excel at high-speed rolling scissors. I guess we cannot know who "won" the encounter for certain, but it certainly seems from reading it is that Johnson's view (as one of the US's leading aces of WWII) was that the P-47 had distinct advantages in dive, zoom climb and high-speed maneuverability. Ultimately, as I say it's about weight of evidence. The P-47 was known for being a good BnZ aircraft, in IL2:GB it's not. The P-47 was known for having strong high-speed maneuverability, in IL2:GB it doesn't. In every other sim the P-47 doesn't have these problems (including some with very advanced flight models) but in IL2:GB it does. Now maybe that's because IL2:GB is right and all of those other sources are wrong .. but the more likely explanation to my mind is that the FM has a bug in it. Many people seem to have the same observation of the P-47 in IL2:GB: the FM is not quite right yet. This wouldn't be so surprising after all: we've had plenty of FM corrections over the years.
  13. No disagreement on the climb rate: the plane couldn't climb well at all. However, every source I've read suggests the high speed performance of the aircraft was considered absolutely top-notch at all altitudes. I can't find the exact quote but there was an account made by Robert Johnson (a P-47 ace) of a mock dogfight with a Spitfire Mk IX, RAMJB describes it nicely here. The 4th fighter group had been training on Spitfires but were then forced to move to the P-47: they didn't like it, it couldn't climb, it wasn't a great turner at slow speeds like the Spitfire and so on. Eventually many of them asked to be moved back to the Spitfire. So Robert Johnson did a mock dogfight against a Spitfire expert: he used the high speed handling of the P-47 to beat the Spitfire each and every time, forcing the fight into a high-speed regime where the P-47 shined and the Spitfire could not compete. They repeated the test several times and each time came up with the same result: at high speeds the P-47 totally dominated. The 4th fighter group apparently never complained about the P-47 after that, having seen the strength of the plane. And this is how it is modelled in other sims I have flown: it can't climb, it's not the best at low speed turning, but it can dive, it handles well at high speeds and it is a very capable BnZ plane. Now maybe IL2:GB is right and all the others are wrong and the P-47 was just a bad plane ... but honestly my money is on the IL2:GB FM being wrong for the P-47, especially with it being such a new plane. As such I'm expecting it'll get corrected eventually in some later update, as most FM issues do.
  14. So there are two main forces we are interested in that are acting on the plane: gravity and air resistance. As explained the acceleration caused by gravity does not depend on the mass (the mass "cancels out" of the equation), a heavy mass accelerates due to gravity the same as a light one (at roughly 9.8 m/s^2). The force of air resistance, however, only depends on shape not on mass: so the force of air resistance is the same for both the light and the heavy object of the same shape, but for the heavy object it causes less acceleration because F = ma (and hence a = F/m, same force, higher mass, less acceleration). So when the plane is diving gravity is accelerating the plane and air resistance is decelerating it. The heavy plane and the light plane have the same acceleration due to gravity, but the heavier plane has less deceleration due to air resistance so it accelerates faster and so dives quicker. Now the planes take their speed from the dive and zoom upwards. Now both gravity and air resistance are both decelerating the plane, eventually the planes will have no speed left and will reach the top of their zoom. Gravity is the same for the heavy plane and the light plane, so it produces the same deceleration for each. Air resistance produces less deceleration for the heavier plane, and so it loses speed more slowly than the light plane and will zoom higher. So this is complicated. It is true that maneuvering a heavier object requires more force .. but it also has more energy with which to do it (KE = 1/2 * mass * v^2). This is why, in general, heavier planes (like the F-15) are no less maneuverable that lighter ones (like the F-16).
  15. I have actually already explained this. I'm just explaining the physics of why heavier objects, in general, dive and zoom better than light ones. I'm not claiming the P-47 has the same drag as a 109, it clearly doesn't.
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