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Turning with the P51and tempest vs 109s. Changed on last path??

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3 hours ago, RedKestrel said:

quite possibly because no one ever did that with a real-life P-47 and documented it.

This. I tend to think the sustained performance of the P-47 is too great, but I dont think there is anything wrong with the way you can do almost flip like peddle turns when it gets really slow. All it really is is a hammer head of sorts. I looks nuts but again, I dont know if we can say its wrong. I might add that this is not the first game I have seen where the P-47 be able to do crazy stunts at low speed with flaps down. It strikes me that if different sims with totally different methods of flight modeling reach the same conclusion, it becomes mathematically improbable that they are wrong in such a specific way.

 

Aces high had, and still does, have some of the best flight modeling in a sim. I know alot of aero types that think it is pretty much the cats meow. I thought this was nuts when i first saw it, but now il2 is the second game where this sort of stuff can be done. It seem to me an awfully specific sort of behavior be wrong twice. Sustained turns with flaps down in aces high were close to what holtzhauge calculated, so less than in il2.

 

 

Edited by [TLC]YIPPEE
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12 hours ago, [TLC]YIPPEE said:

This. I tend to think the sustained performance of the P-47 is too great, but I dont think there is anything wrong with the way you can do almost flip like peddle turns when it gets really slow. All it really is is a hammer head of sorts. I looks nuts but again, I dont know if we can say its wrong. I might add that this is not the first game I have seen where the P-47 be able to do crazy stunts at low speed with flaps down. It strikes me that if different sims with totally different methods of flight modeling reach the same conclusion, it becomes mathematically improbable that they are wrong in such a specific way.

 

Aces high had, and still does, have some of the best flight modeling in a sim. I know alot of aero types that think it is pretty much the cats meow. I thought this was nuts when i first saw it, but now il2 is the second game where this sort of stuff can be done. It seem to me an awfully specific sort of behavior be wrong twice. Sustained turns with flaps down in aces high were close to what holtzhauge calculated, so less than in il2.

 

 

You are joking, right? 

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16 hours ago, [TLC]YIPPEE said:

Aces high had, and still does, have some of the best flight modeling in a sim.

That comic video you posted... I mean, you're joking. Right?

 

17 hours ago, [TLC]YIPPEE said:

I know alot of aero types that think it is pretty much the cats meow.

What aero type? Which cat?

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S!

 

 Aces High was good at the beginning of 2000, but was overtaken by original IL-2 and others pretty fast in all aspects except the MP scenarios. It just did not evolve and stagnated. HTC should have upgraded sooner, not now years later when most games offer way better graphics etc. A shame really.

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14 hours ago, ZachariasX said:

I mean, you're joking. Right?

Nope. And I dont think there is a single person on this forum that could offer a precise explanation as to why its completely impossible. There are stunt planes that can certainly do this sort of thing, which certainly places it within aerodynamic plausibility. Clearly the P-47 was not a stunt plane, but that doesn't necessarily rule out some unusual behavior at very slow speeds with full flaps down. In il2 it basically just amounts to being able to pivot the plane in yaw. Most of what you saw in aces video was completely out of control with some creative camera work.

 

Mind you I am not arguing that it is precisely correct either. To be specific, it absolutely is not. Because no planes specific flying qualities in any sim are exactly correct. Speaking in broad swaths however, I see no reason that a plane could not have some extremely impressive hammer head abilities, because that is more or less all it is in il2. The plane with flaps down has a very low stall speed, small wonder it can flop about while hanging on the prop.

 

As for aces high, the flight modeling in that game is quite solid when it comes to the numbers. Climb rates, turn rates, etc. I could really care less about newer sims attempt to simulate relatively meaningless things like adverse yaw by wasting their time on hard to tune blade element methods of flight modeling. A certain unnamed combat sim does this and and frequently releases planes that sometimes mimic a real planes aerodynamic quirks (like odd landing characteristics) but take 5 years before they can get something as simple as climb rate correct because tuning those models is extremely difficult to control. Of note is that the fact that after years of tinkering, the final flight models in that game produced planes that have almost the exact same by the numbers performance as the aces high flight models 15 years before. And now il2 has produced planes that have the same by the numbers performance as said unnamed sim and sims from twenty years ago. And those numbers are consistent with the independent calculations from holtzhauge. Clearly the modeling wasnt that bad when it comes to general performance.

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3 hours ago, [TLC]YIPPEE said:

Nope

I see, we have vastly different expectations about flight simulation.

 

3 hours ago, [TLC]YIPPEE said:

As for aces high, the flight modeling in that game is quite solid when it comes to the numbers. Climb rates, turn rates, etc. I could really care less about newer sims attempt to simulate relatively meaningless things like adverse yaw by wasting their time on hard to tune blade element methods of flight modeling.

You know, it is very easy and cheap to just hardcode those values. Like they did in the good old days.

 

The end result however will be nothing like the real thing. Planes with almost equal speed and power can be very different in flight. Just fly a Cessna 182 and then an Piper Archer.

 

The biggest fallacy you can enter about vintage aircraft (even cars) is you expecting them to do exactly according to your input. By discarding flight modeling you miss out on simulating a particular type, you just create some space sim that lets objects in the shape of your aircraft move according to some stick input.

 

That aircraft do not necessarily behave as you might think they do is shown here, in an admittedly extreme example:

 

Louis Blériot Jr. trying to reenact his grand fathers flight across the Channel:

image.jpeg.7b480d67ef3b1c366a2d8daae9f59eca.jpeg

 

It should at least have turned out like that:

42889225414_5b3267dab1_o.jpg

 

So why is it blue around the wreck and not green?

 

Answer is that with high AoA wing wrapping aircraft, the aileron work in practise inverted. Also, he failed to realize that some (especially the ancient ones) aircraft are directed by the rudder, rather than the ailerons. The ailerons just being used to control the attitude, inversed from what we have today. He wanted to turn the aircraft by using the stick and it banked in the other direction. His reaction was giving more of the same input and *splash*.

 

You may have noticed in RoF (if you own it) that British ball indicators in the Pup etc. work in the wrong way, you cannot „step on the ball“ to straighten the plane, but rather have do the opposite rudder input for doing so. While you may think inverted controls being another cranky aspect of Britishness like driving on the wrong side of the road, it actually is useful in the context of those aircraft. There, you direct the aircraft with the rudder and then press the stick *in the direction of the ball* to keep it centered. While you might think this is unimportant for a combat sim, I‘d say this is central to learn how to aim with that aircraft.

 

Maybe you don‘t care about these old crates at all, making them not worthy to be simulated. Then let‘s have a look at the newer crates:

4 hours ago, [TLC]YIPPEE said:

I see no reason that a plane could not have some extremely impressive hammer head abilities,

You really think they do? A hammer head (not sure we‘re talking about the same maneuver here) is a very, very difficult maneuver to perform with these aircraft. Maybe ask @F/JG300_Faucon about hammer heads. He knows. But with those high performance fighters, it is barely possible to make such a turn in the direction of the prop torque. Against the prop torque, you would not do that on real life at all. Even with a Bücker Jungman, a plane that just oozes happiness when doing (what is today) mild aerobatics, a hammer head against the prop is extremely difficult and by just missing the timing for a second, it will send you down backward, often followed by an inverted spin (that however looks like a steep spiral but requiring opposite input to exit) that sends your speedometer needle faster toward Vne than you like and what was an aircraft for two fingers to control now requires both you arms and most of your strength.

 

Thus personally, I‘m really happy that these scripted UFOs are in the dumpster of history now as they share very little with actual flight.

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The P-47 low speed full power flaps down behaviour is completely impossible. I could go to great lengths explaining details in aerodynamics and aircraft control, citing multiple sources and making things so complex most people wouldn't even bother to read. But I think it is a no-brainer to even technically uneducated folks that you cannot take off, climb or turn a P-47 at 50 mph in real life, full power, while maintaining control, as you can in game.

 

That, btw., is also specifically stated to be impossible in the NACA report, where the P-47s30 does not reach the full stall in the wave off condition (flaps down, power on (2550/42.5)), because rudder is insufficient to maintain control. That happens at about 85mph IAS - the wing part stalled and rudder fully deflected. In game using the same settings, I climb it at around 73mph no problem. No stall, no control problem, everything peachy. WRONG. By seat of pants, by engineering theory and by a historical source.

Edited by JtD
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15 hours ago, ZachariasX said:

There, you direct the aircraft with the rudder and then press the stick *in the direction of the ball* to keep it centered. While you might think this is unimportant for a combat sim, I‘d say this is central to learn how to aim with that aircraft.

It is not that it is not unimportant. It is that getting this kind of thing right has demonstrated itself to have a inverse relationship to getting general performance correct. In  a perfect world we would have both, but ill take general performance over specific for a combat sim any day of the week. It is absolutely more important to have correct climb rates etc, than it is to mimic certain aspects of control behavior. I am speaking generally here so save me the example that is the exception of the rule, because clearly there will be some. Speaking of just controlling planes in the shape of said plane, I could care less about a combat sim if the game modeled every nuance of control behavior to the point of it being exactly like real life if the two planes in the game didnt have correct turn rates or climb rates with sufficient relative accuracy. With ww2 planes It has to be down to around 2% or extremely meaningful differences in performance occur. A relative speed difference of 10 mph on the deck matters more in most cases than failing to model plane X's adverse yaw. Especially when the most important behaviors could just be scripted.

 

15 hours ago, ZachariasX said:

You really think they do? A hammer head (not sure we‘re talking about the same maneuver here) is a very, very difficult maneuver to perform with these aircraft. Maybe ask @F/JG300_Faucon about hammer heads. He knows. But with those high performance fighters, it is barely possible to make such a turn in the direction of the prop torque. Against the prop torque, you would not do that on real life at all. Even with a Bücker Jungman, a plane that just oozes happiness when doing (what is today) mild aerobatics, a hammer head against the prop is extremely difficult and by just missing the timing for a second, it will send you down backward, often followed by an inverted spin (that however looks like a steep spiral but requiring opposite input to exit) that sends your speedometer needle faster toward Vne than you like and what was an aircraft for two fingers to control now requires both you arms and most of your strength.

Yeah I dont disagree with this in a general sense. Ive spoken to some people with real stick time behind some of these planes as well and the hammerhead was something I discussed once. The person I spoke to essentially said that it is doable but it would be much easier to just let the plane fall backwards and then reverse course at the apex of the climb. However, "this or that is hard" loses alot of its meaning in a sim because people routinely become proficient at doing things no one IRL would likely ever become good at due to risks and time considerations alone.

 

15 hours ago, ZachariasX said:

I‘m really happy that these scripted UFOs are in the dumpster of history now as they share very little with actual flight.

They had about as much to do with flight as the current stuff does. The current stuff just has its own issues. BOTH are wrong.

 

15 hours ago, JtD said:

That, btw., is also specifically stated to be impossible in the NACA report, where the P-47s30 does not reach the full stall in the wave off condition (flaps down, power on (2550/42.5)), because rudder is insufficient to maintain control. That happens at about 85mph IAS - the wing part stalled and rudder fully deflected. In game using the same settings, I climb it at around 73mph no problem. No stall, no control problem, everything peachy. WRONG. By seat of pants, by engineering theory and by a historical source.

Sure its wrong. By 10mph. But this does nothing to explain why the plane should be able to flop about at whatever speed we want to placard it to. I seriously doubt changing the stall speed by 10mph is to going to stop the in game plane from being able to do what it does broadly speaking.

 

 

 

Also both of you are somewhat misunderstanding my position. I am not saying that what we see in game corresponds to a real P-47. No airplane is this game does. I do not know of a single plane in this game that exhibits specific flight behaviors that remind me of what is described in flight manuals or pilot anecdotes. Not on the whole anyway. The point is that the only thing we can really judge in my opinion, is the general aircraft performance. Stall speeds, climb rates, top speeds, etc. Clearly we can know some quirks as well to the extent that they were described by pilots and that their languages was precise enough. But there are lots of things in this game that might be right, somewhat right, etc, that I dont think anyone on here regardless of their education can really know for certain where to draw the line at: short of modeling the entire plane in some kind of CFD(and even then...). I have already said that I dont think the turn rate of the plane is correct at 22deg/s. Clearly the flight model is not correct yet even in general performance. So I think it is fairly obvious @JTD that I am not arguing for a specific speed at which any of this might be possible if I dont think the turn rate is correct. What I am saying is that I dont know that general way the plane handles at slow speeds would change much if you tweaked any of the specific values. And I dont know how any of you could possibly know for certain that the plane couldnt be handled in general in this fashion with full down flaps given that no one here to my knowledge has the resources to do a sufficiently complex aerodynamic check. NOTE ALSO, that this is just one handling characteristic, and some may be provable false and others not. Nobody in the real world tested this for obvious reasons. Given that this is the second time a sim (with totally different FM methods) somehow have come to agreement on the specific handling characteristics of this plane at very low speeds with max flap, I think it is at least worth considering that there may be some truth to it.

 

Edited by [TLC]YIPPEE

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7 hours ago, [TLC]YIPPEE said:

No airplane is this game does.

So far the only plane present in the sim I‘ve flown myself is the Spitfire. I find the devs did a marvelous job in representing both performance and handling over a wide speed range. I am confident that this is the case with other planes. I planning to get stick time on other aircraft recreated in the sim, then I know better. But so far, I have little reason to doubt. Flight behavior at the edge of the envelope is problematic anyway and you‘ll find that even class D full motion simulators can suck there.

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NACA tested this, partially in flight with a P-47, partially in wind tunnels on specific issues with specific objects and therefore we know for certain this isn't possible and we also know a lot about how the P-47 should handle in other areas. Yes, there is some truth to the flaps down power on behaviour, in that this configuration allows very high lift coefficients. But then we also know that they weren't that high, and that the aircraft was uncontrollable at low speed in that config. In fact we know how controllable the aircraft was at what speed in what config.

 

The good thing about engineering (and lots of physics) is, that all laws and behaviours are based on empirical evidence. Means that for pretty much every equasion in existence, someone ran a bunch of experiments until he was reasonable certain how the equation/behaviour should look like. And the particularly good thing about WW2 aircraft aerodynamics - nearly all the experiments still exist and wait for you to find and read them.

 

I'm not sure everyone has read the report I keep referring to, I just know it had been mentioned earlier in the topic so I figured it was known.

Stalling characteristics: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930083857.pdf

Lateral/Directional control: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930083825.pdf

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1 hour ago, ZachariasX said:

I planning to get stick time on other aircraft recreated in the sim, then I know better.

 

Good to know, I'm looking forward to your report on this forum. :)

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Just now, JtD said:

Good to know, I'm looking forward to your report on this forum. :)

Planning to rent a TF-51 Mustang next year. Most however don't have controls in the luggage compartment, so you have to watch out for that. Not having controls eats they same way into your wallet as actually having stick time. And all of these birds are ~£6'000 per hour (or so) flight time. Better think frst before you buy. So far the plan is to go with one or two pilot friends of mine, so we basically would have it for the day.

 

Next up would be the Sea Fury. But the only dual control one I've found is not ready yet, maybe sometime next year. So I guess I'll shift that to 2021.

 

You know. Plans. :)

 

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S!

 

 I have tested Tempest in game and it also can fly fully controllable at speeds of 78mph, without losing altitude, can even climb. Took Spitfire with 150oct for a spin at 100% fuel. Almost managed to do a loop with starting speed of 150-180 imperial whatever measurement. Had I dropped some fuel, propably easily doable.

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Perhaps four issues being raised here and in the P-47 thread, which are linked but need separate analysis: 

 

1) Power off stall speed for Tempest and implications for CLmax - what was, what is, and what might be.

2) How much difference power on makes - presumably this is a global FM question? How much extra airflow behind the prop, depending on engine and prop? How much wing affected?

3) Effect of flaps, particularly on the P-47 which has a huge increase in calculated CLmax when deployed.

4) Control issues close to the limits: is it too easy?

 

This is just trying to keep these problems clear in my head.... :scratch_one-s_head:

 

 

3 hours ago, JtD said:


I'm not sure everyone has read the report I keep referring to,

 

I think you can be fairly sure that they have not....  just taking a gander now...

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With all respect to you Gerasmos, I will use you post to ask the admins why my post was close after only 4 replies. Gerasmos like me, are discussing situation about the turn availability of red planes(6 pages until now), I about the power of the ammo on blue planes.

 

Need and explain.

 

 

 

Edited by ECV56_Necathor
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