Not being an expert in mechanical engineering, but having some insight after all the years.. I can only imagine that the Merlin's torque is applied over a few feet of engine length, whereas the BMW801 (sorry JTD :grin: ) torque is applied within a few inches of length.

This I would think and experienced, if Oleg has modeled it right, caused the FW to screw/hang on the nose... maybe similar to the Camel or Fokker DR1 from WW1, whereas the merlin just pulled the plane over due to it's application of torque over a longer length, making it difficult to control if you walled the throttle

Yes.. he is aware of the term ;)

I suspect it had more to do with the design of the prop. Those on the Spitfire were a lot larger than those on the Fw190. The forces and lift generated by the prop would be magnified on the Spitfire as they were further away from the Fuselage.

I admit to pushing my theory here as these issues are not a real problem in Gliders.

Sorry, I'm talking about about the longitudinal length of the camshaft along the length the the engine, which is longer in the Merlin compared to the BMW801.

But, yes I notice that the Spit props were longer and thinner.. but this is beyond my current knowledge. :)

Maybe Gaston's mechanical adversary (cannot remember his forum AKA) will chip in here..?

Torque is simply a result of power divided by propeller rpm. The Fw had a prop reduction gear ratio of 1:1.85 = 0.54 with engine rpm 2700, the Spitfire IX a ratio of 0.477 with engine rpm of 3000. This puts the prop at 1458rpm on the Fw, and 1431rpm on the Spitfire. Engine power output of the Fw is higher at low altitude, but somewhat lower at medium and high altitude, and, given the very similar rpm, torque is going to be the same.

However, torque isn't the real problem, the gyro effect of the spinning prop disc is a bigger one. Torque is something you can trim your aircraft for and then can pretty much forget about, but gyro effects are something you'll notice every time you maneuver the aircraft.

To estimate the gyro effects, you'd need prop speed, diameter and weight, which I don't know where to look up from the top of my head, so I'll skip this one, but I doubt there'll be a huge difference.

One of the relative strengths of the Fw compared to the Spitfire were the very well balanced controls, which made handling easier and smoother. This is also a feature that definitely is present in game.

Personally I am waiting for Gaston to take up my challenge.

If you have read all the 600 P-47 combat accounts and still don't know the P-47 badly out-turns the Me-109G in all circumstances, then there isn't much point in providing any evidence is it?

I have for years presented all of you out there with the challenge to find one combat example of the Me-109G out-turning the P-47, in any circumstance, but especially at low speeds, and still nothing has come up...

If you don't see that P-47 turning fights outnumber the one dive and zoom example you provided (indeed correctly) by a ratio of about ten or twenty to one, I wonder what is the point in debating the issue further: There are 600 P-47 combat accounts here, and so far you have provided one dive and zoom example and I have provided one more: I have read them all and there isn't a large number of those compared to P-47 turnfighting...

P-47 turnfighting also outnumbers P-51 turnfighting, and especially P-51 turnfighting at medium-low speed turning when decided within less than five-ten 360°s. Within one unsustained 360° at high speeds, the P-51 does excel occasionally at very high Gs.

However I will break it down into the actual numbers and ratios for those 600 combat reports when I have the time.

Gaston

Didn't think you would take up the challange.

Just to avoid any confusion this is the challenge

I have a challange for you. Pick any combat, from any of the lists you like, be it a Spitfire, P47, P51 whatever, totally your choice. And we will analyse the ten combats either side of the one you picked and see how many of those involved involved a turning horizontal combat.

I repeat the choice of aircraft, list and combat is totally yours. I don't think I can be fairer than that.
Lets see if you are willing to use those combat reports to prove your point

This in relation to your 95% of all combats involved turning combats

I have already disproved your statement about the Slow turning Spitfire combat, you will remember your statement that nearly all high speed turns are stall turns. I also disproved your statement about P47's not fighting in the vertical, remember that you only found one example and it took me four minutes to find another.

So right now your batting average is less than good.
I am confident that I can disprove your statement about 95% of air combat being sustained turns thats what the challange is about.

Why don't you provide the examples. So you can start with the 10-20 examples of a P47 fighting in turning fights.

PS another fire and climb example http://www.wwiiaircraftperformance.o...-29april44.jpg
PPS another one http://www.wwiiaircraftperformance.o...-29april44.jpg
PPPS And another one http://www.wwiiaircraftperformance.o...in-30jan44.jpg
PPPPS Guess what http://www.wwiiaircraftperformance.o...e-8april44.jpg

edit Re the P47 turning compapred to the Me109. I have always believed that this differs with speed. At the slower speeds the 109 would have the advantage, at higher speeds the P47 (and P51) gain the advantage. This is down to the simple fact that the 109 control forces become very difficult at speed, a fact reported in a number of pilot statements and generally supported by the combat reports

The P47 was great at altitude and speed, as much as it was good for ground attack, it excelled at high altitudes as well... according to one vet :grin:

If battles were high and if it had speed the P47 could win easily, but as soon as it slowed down, it was a sitting duck. In fact nearly all allied a/c were ducks at low speed, with exception maybe of the spit.
The axis planes seemed to be easier to handle at low to medium speeds.

I totally agree with you. Tempest pilots were continually told not to get into a slow turning fight with the 109.
As mentioned before the Tempest had a broadly similar turn performance as the P47/Typhoon/P51 and Fw 190 so it fits

Reality checks --
* wing loading and excess thrust are the 1st order factors. 2nd order is less.
* say hello to stall speed differences

At low speed the stall speed is critical which goes right to wing loading.
The plane that has the lower stall speed can still turn where the other cannot.

In banked level turns the lift is tilted, you need to have enough to keep the plane level, wings at stall angle must fly faster to make the extra lift needed to both hold the plane up and turn.

Excess thrust which changes with speed and height only determines when a plane can no longer hold stall.

Look at FW stall speed compared to what others you want.

Or you can take bits of war stories that tell less than they leave out and weave them with poetic license into a fabric fit for fairies and other fantasies. To call that reality or historic is a shame.

What you say is correct but equally the control forces do have a bearing on the high speed turns.

No one would deny that the Zero was one of the best slow speed turners, but at anything above 250mph the controls were almost rigid and as a result its actual performance in a turn at these sppeds was very poor. Had the controls been given a different gearing/ configeration whatever then she would probably have been an even better all round fighter.

It was a similar story for the 109 but the critical speed was higher.

I have little doubt that the calculations and theories would say that the 109 and Zero had the wing performance and power to turn at higher speeds, but if you cannot move the controls then are going nowhere other than in a straight line or a gentle turn.

"No one would deny that the Zero was one of the best slow speed turners, but at anything above 250mph the controls were almost rigid and as a result its actual performance in a turn at these sppeds was very poor. Had the controls been given a different gearing/ configeration whatever then she would probably have been an even better all round fighter."

I don't mean to throw (another) red herring into the mix but that's an interesting point. Could the turn performance of a fighter be altered in this way, or by simply increasing the size or throw of the elevators?? I don't know but I suspect not. It seems unlikely that the engineers of the day were unable to come up with such an obvious and easy fix for something like the 109.

Its something that is probably easier to say than do. The Size of the control surfaces clearly has a bearing on this. However, make them smaller and the plane loses some of its agility. Change the config and you have to change the wing design with obvious complexities. Change the gearing and the aircraft will handle differently in particular the secondary control effects.
Its a big change and I was wrong to imply in my previous posting that it was straightforward.

The basic design of the Spit wing didn't change until the Mk20 right at the end of the war. The P47 until the H again at the end of the war, The Fw 190 until the Ta 152 again at the end of the war. The only front line fighter that I can think of that significantly changed its wing design early in the war was the Me109 F in 1940.

My main point was that the force needed to change the controls does impact the planes ability to turn at high speed. Sabru Saki made the observation that a lot of the suicide pilots who just missed their targets when diving in a Zero, probably were unable to move the controls because of how they locked up at speed.

GASTON

Still waiting for you to come up with a reply to the challange in relation to your 95% of all combats involved turning combats

Just to avoid any confusion this is the challenge

I have a challange for you. Pick any combat, from any of the lists you like, be it a Spitfire, P47, P51 whatever, totally your choice. And we will analyse the ten combats either side of the one you picked and see how many of those involved involved a turning horizontal combat.

I repeat the choice of aircraft, list and combat is totally yours. I don't think I can be fairer than that.

You keep saying that have studied these for years, that they support your statements and that I haven't read them.
Yet we find either :-
a) that you have no idea what they say or
b) you do know what they say, ignore it and are therefore lying

So lets see if you are willing to use those combat reports to prove your point, or when challenged, do you run away and hide as you have done before on other forums.

"...But how am I to know a good flight model from the bad?"
"You will know... when you are calm, at peace, passive. A pilot uses the flight model for positioning and defense, NEVER to attack."
"But tell my why I can't..."
"No, no! There is no why."

Seriously though, I read through this whole conversation and I noticed two trends: Cherry-picking data, and magical thinking. There have been more than one person to do this in this conversation.

Cherry-picking data means that you look at accounts, pick the ones that support your opinion, and analyze them with the exclusion of other, conflicting reports such as actual, physical hard data about the aircraft themselves - their mass, wing area, engine power, thrust, control forces, critical angle of attack, stall characteristics etc. etc.

Magical thinking is a bit more complicated and is a continuation of the cherry-picking process. Since pilot accounts describe plane A in a way that contradicts our understanding of flight dynamics, and what its performance should be, the pilot accounts must be right and our understanding of flight dynamics OR the parametres of the aircraft A must be wrong.

This is magical thinking: "To match pilot accounts, magical properties must be added to the aircraft so that no conflict occurs."

However, when it comes time to explain what physical phenomena facilitate these properties, things become a bit difficult because mechanical physics is, on the most part, quite well known collection of knowledge and adding "unknown flight characteristics" smells incredibly fishy.

It's like trying to explain Grand Canyon if the preconception is that the world is only eight thousand years old: Since the world can't be billions of years old for these sediment layers to slowly form, there must have been a global flood that accumulated all these sediments at one go! This has, actually, been used as evidence for a global flooding... along with the fossil record... but I digress.

While I wouldn't wish to accuse anyone of dogmatic faith in scripture or pilot accounds, I can't help but notice certain tendencies in the argumentation on this thread.


In reality, I would not automatically consider any pilot accounts - either combat- or test pilot - "reliable" accounts of the characteristics of the aircraft itself, but rather specific accounts of what this pilot did in this particular situation against that pilot in that plane and how it happened to work out. Additionally, you're assuming that the undoubtedly highly skilled, experienced and intuitive pilots had the ability to put their experiences, feelings, and fly-by-the-seat-of-their-pants gauging of different planes into objective format.

It's absolutely right that pitting aircraft against one another in evaluation test flight might not reveal what plane is the "best one" at some specific flight regime. But comparing the accounts of combat pilots is not exactly reliable either, because - you know - the accounts are written mostly by surviving veteran pilots who were probably both highly experienced and biased toward their own particular aircraft. This type of bias is perfectly normal and expected from humans put into situation where their life hangs on the performance of a machine and how well they can handle said machine. It's easy for the most rational person to ascribe almost mythical qualities to such a machine, especially if it happened to bring them home time after time.


Regardless. Ignoring the possibility of hidden variables, I'm sure we can all agree that the laws of physics apply on aircraft regardless of their type, manufacturer or pilot. The pilot can bring them closer to the edge of their performance, and possibly do tricks that other pilot can't, but as far as raw performance goes, the capabilities of an aircraft are fairly straightforward. I say fairly because aerodynamics is a really complicated science and there are often surprises even from quite simple designs, but nevertheless some simplifications still hold true.

If we look at a situation where an aircraft is turning, there are two key variables that describe its performance. Ones is turning radius, and the other is turn rate. Transient turn rate (and turn radius) mainly depend on the g-loading of the airframe at critical angle of attack, but transient turns bleed energy - the aircraft's energy state is not at equilibrium.

In sustained turn, the aircraft is banked and has elevated angle of attack, produces lift toward the direction of the turn, and maintains constant airspeed (producing constant lift), constant turn rate and constant turn radius.

The first requirement is constant airspeed. The aircraft typically produces quite high amount of drag with high angle of attack, so the aircraft's engine must produce the thrust to offset drag so that the airspeed does not further reduce. Since thrust is (mostly) a function of how much air the propeller can move, this is pretty much a function of propeller efficiency and engine power: The work done by the drag forces must be equal to the work done by the propeller's thrust.

Therefore: An aircraft with more thrust can maintain higher angle of attack and therefore its sustainable rate of turn is better. Inversely, however, an aircraft with less drag at optimal angle of attack might well be able to sustain higher turn rate at lower engine power, so this is not at all clear-cut parametre. A simplified expectation would be that an aircraft with more engine power should be able to sustain higher turn rate assuming other variables are identical.

The constant turn rate and constant turn radius mean that the aircraft can produce a constant centripetal acceleration, ie. a force accelerating it toward the centre of the turn. While vast majority of this force is basically the lift of the aircraft's wings and control surfaces, at very high angles of attack the propeller's thrust is also partially directed "inward" of the turning circle. In fact, if you're dancing at the edge of stall - critical angle of attack being let's say 15 degrees - as much as 25% of the aircraft's thrust is directed "upward" relative to the local airflow around the aircraft. While the main function of the propeller is to, should we say, propel the aircraft through air, its effect on "hanging on the prop" in high AoA turns should not be neglected.

That said: Most of the centripetal force is accounted by the lift produced by the aircraft's wing at that specific angle of attack.

Centripetal acceleration, then, is the sum of aerodynamic pressure forces divided by mass of the aircraft (a = F/m).

Note that most talk about wing loading is, at best, a gross simplification that assumes the wing's characteristics are very similar between two aircraft.

Wing loading, as a parametre, is merely the mass of the aircraft divided to the total surface area of the wing. While somewhat indicative of the general characteristics of the aircraft - especially within a specific class of aircraft such as WW2 fighter aircraft - there can still be radical differences in performance. Wing loading does not determine turn performance. Total lift produced by the aircraft does, and wing area is only one part of that equation.

The other part of the equation is the wing's airfoil profile. The two most influential factors are the wing's camber and chord thickness. Those are the ones that affect the wing's lift coefficient most. Other variables tend to affect the wing's critical angle of attack and lift-to-drag ratio.

I found an interesting site which includes references to the approximate airfoil shapes of quite a few aircraft: http://www.ae.illinois.edu/m-selig/ads/aircraft.html


For example:

Focke Wulf Fw 190A-8
Wing root: NACA 23015.3
Wing tip: NACA 23009
Chord thickness ratio (root/tip): 15.3% - 9%
Wing loading: 241 kg/m² / 48.4 lb/ft²
Power/mass ratio: 0.29-0.33 kW/kg

(I couldn't find A-5 wing loading but if the A-5 variant's loaded mass is known it would be trivial exercise to find out).

Focke Wulf Fw 190D-9
Wing root: NACA 23015.3
Wing tip: NACA 23009
Chord thickness ratio (root/tip): 15.3% - 9%
Wing loading: 238 kg/m² / 48.7 lb/ft²
Power/mass ratio: 0.30-0.35 kW/kg

Supermarine Spitfire Mk. V
Wing root: NACA 2213
Wing tip: NACA 2209.4
Chord thickness ratio (root/tip): 13% - 9.4%
Wing loading: 133.5 kg/m² / 27.35 lb/ft²
Power/mass: 0.36 kW/kg

Supermarine Spitfire Mk. IX
Wing root: NACA 2213
Wing tip: NACA 2209.4
Chord thickness ratio (root/tip): 13% - 9.4%
Wing loading: 159.8 kg/m² / 32.72 lb/ft²
Power/mass ratio: 0.42 kW/kg


For some reference, here are some chord thickness ratios at wing root and wing tip from some other prominent fighters:

F4F Wildcat: 15.3% - 9%
F6F Hellcat: 15.3% - 9%
F4U Corsair: 15.3% - 9%

(Identical airfoil profile with FW-190, tremendously lighter wing loading...)

La-5/F/FN/7: 16% - 10%
MC.205: 18% - 9%
Bf-109 G-6: 15% - 9% (NACA 2315 mod - NACA 2309 mod)

Hurricane: 19% - 12.2%
Typhoon: 19% - 13%
Tempest: 14% - 10%

MiG-3: 14% - 8%
Yak-1/7/9/3: 14% - 10%


Now what has this got to do with anything on this thread?

Well, aside from wing area, the chord thickness affects the amount of lift that the wing produces.

That means that if you have same nominal wing loading on two planes, but the other one has thicker wing, the one with thicker wing is producing more lift. For example, the Hawker Hurricane has wing loading of 121.9 kg/m² which is only 11.6 kg/m² lower than Spitfire Mk.V's wing loading - but the thicker wing would produce more lift, which pretty much explains why the Hurricane turns so much better than Spitfire both in-game and by the pilot accounts:

More lift means more centripetal acceleration.

More centripetal acceleration means higher sustained turn rate.

But wait, that's not all! Higher chord ratio means that the wing also produces more drag. So that means the aircraft will need more engine power to offset the work done by increased drag force, or it will travel slower through the sustained turn - and reduced airspeed reduces available lift which reduces centripetal acceleration which reduces the sustained turn rate.

True to this assumption, the Hurricane really does lose its energy quite fast in hard turns and while its sustained turn is still better than Spitfire's, it is also really slow at that point.


Spitfire's wing is slightly thinner than the FW-190 wing at root, but slightly thicker at the wing tip; however, as the FW-190 wing was trapezoid and Spitfire wing elliptical, the root chord of Spitfire has much bigger significance and it can be said that Spitfire's wing is overall thinner than FW-190 wing.

What this means is that while FW-190 A-8's wing loading is as high as 241 kg per square metre and Spitfire Mk.IX's wing loading is 160 kg per square metre, the Spitfire doesn't in fact turn 33% better than the FW-190 A-8. Instead the difference would be somewhere between 0%-33% in unpowered turns. In sustained powered turns, the thrust of the propeller will also affect things as it is directed "outward" from the turning circle, and the thrust/weight ratio also comes to play - and Spitfire IX has a lot more power.


So how can we make any sense of any of this?


The answer is: It's really hard, really complicated, and the vast odds are against armchair pilots trying to think how each of these parametres affects each other.


As far as simulation accuracy goes... if you have a good flight dynamics model, and you have the correct values for relevant terms for the aircraft, they should have close to historical performance characteristics.

Will they behave like the planes historically did? Hell no. First of all most pilots in IL-2 tend to operate very differently from the paranoid survivors who checked their six every twelve seconds, kept track of everything that happened around them, and aspired to never put themselves in a position to get shot at, while putting themselves in a position where they could shoot at the enemy.

As has been said in this discussion, bullets flying tends to motivate men and mice. In a real combat situation, a lot more factors affect the outcome than just the performance of the aircraft. For example, FW-190 offers much better all-round visibility than the Spitfire (or Bf-109 for that matter). Additionally, when Bf-109's and FW-190's were operating together, it would make perfect sense for the FW-190's to fly at lower altitude and Bf-109's at higher altitude because the BMW engine was inferior at higher altitudes compared to the DB engine of the 109.

I am reasonably certain that no FW-190 pilot would have wanted to enter into a sustained turn fight with any allied fighter aircraft if they had any other choice.

As the facts may be, they often may not have had any other choice as the quality and amount of material and pilots on the Allied side grew and Luftwaffe was run over by P-51's, P-47's, Spitfires, Tempests etc. etc.

Whether or not any of these designs were objectively "better" at turning than FW-190 or Bf-109 didn't really matter much at this point. The Luftwaffe fighters' main task was to go after the bomber fleets, and they would have tried to avoid combat with Allied fighters as much as possible.

And even so: As the war progressed, many Allied fighter pilots flew all their sorties with no enemy combat, while Luftwaffe pilots engaged in combat almost every sortie. Is it a big surprise that pilot accounts of the capabilities of individual aircraft may have been skewed by the other factors affecting the set-ups of the individual fights? I think not.


If there's something I've learned while studying physics it is that complicated interactions of a veritable horde of parametres is not always quite exact science and often the only reliable data comes from experimentation.

Sadly, the majority of war-time fighter aircraft have been destroyed or otherwise rendered flightless. The best solution to the question of evaluating flight performances would be to construct new production planes of each fighter, and then test their performance.

Needless to say this may prove somewhat expensive, so in lieu of that, the best alternative is to look at the sources of data, form some sort of opinion on what data to use, and then use it. In the end, this is first and foremost a game. As much as I would love to know that the aircraft we fly on bit sky are accurate representations of their real world counterparts, I'm willing to accept that sometimes we can't get what we want quite as much as we want.

With that in light, as long as I'm having fun and I can find viable ways to use different aircraft in the game, I can live with possible historical inaccuracies.


Finally, an anecdote.

I have encountered a couple FW-190 pilots in this game that would outmaneuver a Spitfire flown by me. I have, on occasion, done so myself. But whether "outmaneuver" is the same as "out-turn" is anyone's guess...

End of story. Take of it what you will, ignore the rest if you wish.

@Glider:

Eric Schilling described the 'barn door' ailerons of the Zero as the same kind of limit that you do.

Even the term high speed, IMO is relative to the plane and not absolute. But those Gaston-claims from 2008 (yup, read the post dates) keep going to FW's out-turning Spits at low speed.. are much easier to shoot down.


Herra, you should have been around 8-10 years ago when the aero-engineers were posting actively. All the little details, the full 9 course meal was laid out and the result was more to disagree on!

As to pilot stories, just count the missing details starting with who was piloting the other plane(s) or how good were they? Don't forget that 'much' is not a detail! In the end, if they tell 10% then that is a very detailed story.

I have no doubt.

Yep, exactly my point. It's unlikely, and unfair, to expect pilot accounts to be a viable source of objective information, considering most anecdotes come from pilots who happened to survive multiple encounters with the enemy.

The dead men tell no tales of why their aircraft "failed" them while the survivors claim that you could outmaneuvre spitfires with FW-190's - a claim, I am certain, that was absolutely certain with regards to early FW-190 A versus Spitfire Mk.V's, but outmaneuvering... outflying... power, climb, dive speed, roll rate... it's not necessarily the same as "turning harder" (though that does help).

Fact is, ALL the aircraft in the war - were a product of their time, derivatives of same technology and engineering principles. Most of them could do the same things as the other, with small variations on how fast or how well or how hard it would do thing X, and it was up to the PILOTS to identify the strong points and weak points versus this or that aircraft, and then USE the strong points while AVOIDING the weak points against that particular aircraft. The pilots with good situational awareness, or the lucky ones who managed to gain enough experience to learn the basics, would usually survive longer and longer as their experience about their plane and the enemy planes increased.

I remember hearing that during the Battle of Britain, if you survived the first five sorties, your odds of surviving the whole war increased exponentially, and this is exactly why, in my opinion.

And now you have the surviving pilots telling how they out-turned the enemy plane, so you would likely find anecdotes about ANY plane having out-turned ANY enemy plane. Question is whether the enemy plane was turning as hard as they could. After all, the bandit you don't see is the one that gets you. As long as you can maintain visual contact on an enemy, you can usually evade pretty effectively even if you are flying "inferior" aircraft - either in energy, angles, or both aspects.

But when you're not sure where the enemy is, and you're trying to locate them, you don't necessarily turn quite as hard as you could because you like being able to see and breathe and turn your head without breaking your neck... that's when the FW-190 that has your Spitfire in your sights will "out-turn" you, maybe?

I could think of a myriad more reasons why pilot accounts, interesting stories as they are, should only be viewed as evidence of why that pilot happened to survive the war, and not necessarily so much related on the aircraft they flew on. Then, flight valuation test data and performance data of engines and airframes from the most reliable sources remains the best option...


More anecdotes: Finnish Air Force pilots tend to have thought almost universally that there was not much difference between the turning ability of Bf-109 G-2 and G-6 - only if you had wing cannon gondolas, the handling of the G-6 would be significantly reduced...

...and the leading Finnish ace, the highest scoring non-German ace (Eino Ilmari Juutilainen) finished the war with 94 confirmed aerial combat victories in 437 sorties, without having ever been hit by enemy aircraft. He also never lost a wingman.

Naturally, from this anecdote we can deduct that the Bf-109 G-6 and by extension all the other late Gustavs are undermodeled as far as their turning ability goes! ;)

Or Finnish pilots are overmodelled :cool:

Overmodelled no, cool certainly

First time Russia sent troops to Finland they found that the whole Finnish military was over-modeled! But quantity has a quality all its own... :(

Really, in the old Avalon Hill Panzer Leader series design notes they rated the Finns so highly that the regulars were treated as elite officers.

This happens when you shoot people without realising that they're your best you'll ever have.

That's him, the one I forgot ... MaxGunz ;)

So that we're now all back +- a few extras.. are we agreed that the aeronautical engineers do not know everything about aerodynamics, as well as the pilots do not know much about aeronautical formulae ??

;)

AE's can tell you to what decimal point they know and prove it.

People expect too much from computers and algorithms they can run.
--------------------------------------------------------------------------------------
* To match charts everywhere and still give every effect possible is not possible on a PC is not a failure of aero-engineering.
* To know all the details of historic planes without the actual planes is also not possible given that serially produced planes did vary often as much as 5% in a production run.
* Gauges of the times have different kinds of error including position error so we have seen a picture of 2 fighters wing to wing where IAS on one was 20 kph more than the other. How can anyone play comparison chart monkey when that is true? How can their knickers get so twisted over 'FACTS!' that are not?
* Flight sim makers bring however much they can make work on the PC of what they know. It is wrong to try and judge what they know by how the sim works.

You want to play "all opinions are equal", it is because you can't tell any better. You might as well invoke the influence of the planets and stars or even resort to "stress risers".

I am reminded of a story a friend told me of a conversation he heard at an Aircrew Association gathering with vets from the Luftwaffe and the RAF/RCAF. One Hurricane pilot was talking with a Do-17 pilot of the same vintage. He was saying how fast the Do-17 was and relaid his constant cursing that his Hurricane was not fast enough.

His counterpart chuckled and said he always thought the Do was too slow and they were too easy to catch. When you are trying to catch (or run away from something) you are never fast enough or I would imagine, able to turn tight enough. Perspective is everything.

This was actually done with the ailerons when the P-36 was upgraded to the Allison engined P-40. The leverage was increased, which meant less maximum aileron deflection at low speed (stick travel limit), but more aileron deflection at higher speeds (force limit). The P-40 had a lower roll rate at low speed than the P-36, but a considerably higher maximum roll rate and a much higher roll rate at high speed.

Indeed, I do believe that until the FW 190 came along the P 40 was the roll rate king of fighters.

Thanks for this, something I didn't know before. It helps explain why the P36 did as well as they did against the Ki43 when it didn't have the speed advantage that the P40 had.

Thanks again

They say when holding a weapon, one should point it skywards as you might shoot yourself in the foot. :cool:

Do you know of any FW-190A pilot who actually said such a thing?

The only concrete thing in that direction I ever found, for all of WWII, is a ridiculous quote from a German La-5 Rechlin test center evaluation: It said that the La-5FN's sustained turn rate is slower than a Me-109G, but faster than a FW-190A's...

It positively reeks of ignorance and sillyness, and the Rechlin test center itself has said several times textually the opposite ("The FW-190A out-rolls and out-turns our Me-109F at any speed"), but it's there...

Another quote, in the same direction, is a comparison test between the Me-109G14AS and FW-190A-9s at 26-28 000 ft., which puts the Me-109G14AS as far faster turning at said altitude (where the FW-190A can barely fly), which is very plausible given the absurdly high and impractical altitude of the test, given the time period and the available roles for the Luftwaffe at the time (late '44)...

That's it for my fifteen years of research... British RAE tests unequivocally state the FW-190A turns far better than the Me-109G, which Me-109G is out-turned by a P-51B with full drop tanks, while the same P-51 cannot out-turn the FW-190A even when clean... It seems the Me-109G is badly short-changed here (it has only a slight disadvantage to, occasionally, a perfect sustained turn parity to the P-51B in actual battles), and this, to my mind, just shows how unreliable these non-combat side-by-side tests can be...

Given what else I've been finding for fifteen years now, and posting for five, I'd say you'd be up the creek finding such a ridiculous agreeing statement (to what you said) from an actual FW-190A combat veteran.

Occasionally some FW-190A pilot did believe this crap, judging from their continual use of diving and ailerons in combat, but judging from the outcomes of those tactics, these pilots typically didn't live long enough to voice their opinion about it...

Gaston

Well, I'm just pretty sure no pilot flying ANY PLANE would have ever wanted to enter a prolonged turning fight with any fighter, if they had alternatives...


To be sure, I personally think IL-2 does not sufficiently model the control forces required to maneuver at high speeds. An FW-190 would very likely out-turn a Bf-109 if the pilot in 109 could not use full control deflection due to excessive control forces. Same applies to P-51.

Additionally in the Bf-109 we can use both the trim wheel and flaps fast and with no difficulty; I would love to see the octopus pilot that can juggle all that in combat. The flaps in 109 were very slow to actuate and fully manual - you turn a wheel in cockpit and the flaps go down, you couldn't really actually use "combat flaps" as a quick decision - you would have to set combat flaps position before hard maneuvering.


The pilot makes an incredible difference in these birds. Especially in Bf-109 where not only pilot's skill but physical constitution and strength would definitely affect the aircraft's turn performance at high speeds. Just as A6M would roll better when pilot could exert higher force on the control column. Every virtual pilot has identical strength to move the controls, when comparing two pilots in two identical planes. Whether that strength remains constant from plane to plane is anyone's guess.


The actual physics of the matter are not exactly up for debate, though. The comparative weighs, lift capabilities of the wings, thrust from the propeller... all these factors are well documented and can be modeled quite well, physical testing notwithstanding.

Fact of the matter is that the 109 had lower wing loading, better thrust-to-weight ratio, and very similar wing chord profile as the FW-190. That means at similar airspeed and angle of attack, the Bf-109 wing would be able to produce better centripetal acceleration, reducing in better turn rate and (at same airspeed) smaller turn radius.

To me that tells that when flown to their capabilities the 109 would probably have no problems out-turning FW-190 in a prolonged horizontal plane turning fight, and moreover would have no problems controlling the engagement in vertical plane due to better turn rate. The FW-190 pilot would be insane to offer such fight when the plane is faster anyway (at low to medium altitudes).

Stall speed shapes the low speed limits of flight and maneuver. Those stall speeds are historical qualified and quantified facts, not unqualified comments or unsupported opinions taken further for an agenda.

Of course you can always bring up "stress risers" again, or find some other fake buzz word to crank that cracked theory along.

15 years of playing with words and discounting everything that says the 190 wasn't a great stall-fighter vs people who model the planes based on REAL parameters and full educations in aerodynamics who say different. Hmmmm, boy, ain't dot tricky eh?

Ah! it's good to have all back again...
As we've settled down to the aerodynamic theorists, who professes to know everything, and the pilot who experiences everything....

Is there any pilot report that can explain the different facts explicitly - probably not.

On the other hand is there any aerodynamic 'theorist' who has explicit flight knowledge of the aircraft in question - Zippo ;)

So who are we to trust in this scenario - I'll take pilot experience any day, tempered with a bit of common sense

The biggest difference on all aircraft designs was that Kurt Tank, was a pilot, beside FW190 design engineer.. :)
Yup.. I'll still stick with Gaston's theory

Glad to see that you re still alive Gaston.

As for your 15 years of research I don't believe a word of it. Please take up the challange I have given you a number of times. If you can prove your point using the evidence you claim then you have some credibility, without it you have none.

You can of course supply the British tests which say what you say :-

That's it for my fifteen years of research... British RAE tests unequivocally state the FW-190A turns far better than the Me-109G, which Me-109G is out-turned by a P-51B with full drop tanks, while the same P-51 cannot out-turn the FW-190A even when clean... It seems the Me-109G is badly short-changed here (it has only a slight disadvantage to, occasionally, a perfect sustained turn parity to the P-51B in actual battles), and this, to my mind, just shows how unreliable these non-combat side-by-side tests can be...

I say this as you have considerable form for saying things that are not supported and as a result are not true.

It's not a good idea to stick with a theory that ignores 80% of the facts and misinterprets another 15%.

The pilot who experiences everything... LOL! What poetry! What utter nonsense!

What's behind stall and low speed turning is well within demonstrated facts. It's something that -all- those pilots had to learn right at the start. If you don't think so, find an old ground school manual.

If you want to quibble 2 or 3 places past the decimal and offhand say that makes aerodynamics knowledge of flight less than that of not a combat pilot but of some non-pilot, crap-math-and-science gamer's interpretation of what the combat pilot wrote as an after-action report or war story then go ahead if it lets you feel better about yourself but you're wrong.

Herra is making a good point about control stiffness in certain flight configurations.

There is also the issue of G load on the capacity to effect the controls as your limbs are pulled in another direction.

High G load sustained turns will tire the pilot out and make him dizzy.

Maybe a Spitfire pilot who just escaped a couple of passes by a 190 through pulling as hard as he could on the stick will be tired out.

Maybe the 190 pilot would notice that the turns are not as sharp any more and now easily turn with him.

Nothing to do with actual Aircraft performance, though.

Just my tuppence.

So, aerodynamic maths explain 100% of flight, a 100% of the time and the pilot's always wrong, according to the 'propellor head' on the ground.

You sound like an aircraft crash investigator out to needle the pilot, as they usually do. Not that they always wrong, but they not always right and in this situation not likely to accept this.
;)

I gave it a 5% margin.

I was thinking up to 10%, which is why I'll allow Gaston's argument.

I'm well aware of the manuals and their contents, the pilot errors, etc...
While not being a Mech/Aerodynamic engineer, I do work in the engineering field.. some 34 years of it, some on aircraft and some pilot time. So I am no stranger theory, formulae and modelling.. as well as the practical side, plus all the goodies that go with it.

Putting this all together, I'm not going to rule out Gaston 100%.
;)

Just one more thing, said Columbo. What about computer games besides Il-2? It seems that Fw-190 made first appearance in Secret Weapons of the Luftwaffe (1991) (I can do research too, ha ha ha), and it wasn't a great turnfighter there, and so it has been ever since in all games to follow. Do you guys think that the all of the game designers who put 190 in their games did their research wrong?

It's like Stats.. you see what you want to see.
Before IL2 came out not many (in the west) knew that there was a war on the eastern front, never mind a tank busting machine like the IL2, I mean the P51 won the war.

I at the time believed all that 'research' too, but Oleg opened our eyes.
Now I'm a bit wiser about being too judgmental.
;)

Wow, I haven't posted about Il-2 for a very long time, but just cannot resist with a comment like the one below:

Actually, it does. For the simple reason that flight is described "perfectly" by the laws of physics. There are no exceptions. At least, in many years of flight testing from inside the aircraft and from a telemetry station on the ground, I have yet to see a single case of an aircraft defying the laws of physics. Also, today the knowledge surrounding the various factors that contribute to the forces acting on the aircraft are very well understood and can be modelled very accurately - at least accurate enough that the prediction models get extremely close to the measured ones.

When it comes to flight simulation, however, the programmers must strike a balance between fidelity and practicality. The most difficult part is not to model the kinematics - the equations are quite simple - but to generate the data to populate the models. To generate this data is both time consuming and costly. I have worked with simulators where the fidelity was so high, that we would sometimes only use spot checks in actual flight to confirm the simulator predictions. However, to achieve that level of fidelity took wind tunnel tests, numerical predictions (such as CFD) and also in-flight systems identification. The costs are obviously staggering to create such a model. This is not feasible for a game, especially ones where more than one aircraft needs to be modelled, so developers have to make some decisions on how far to go in the modelling process. The result will always be a compromise. It doesn't mean there are some voodoo aerodynamic effects going on that engineers don't understand.

I don't think it is one or the other: I often rely on test pilot comments during testing. However, what is very true and I think both you and Gaston seem to miss, is that the combat environment is probably the worst possible time to compare aircraft performance. There are just too many things going on to make any quantitative judgement, unless the differences between the aircraft are really large, such as a jet vs a piston-prop. For example, does the other guy really have a faster aircraft, or did he just start the fight slightly higher and was able to build up some energy into the merge? Or does he really turn better or is the fight just happening closer to his corner speed than yours? Half the time, you won't even remember your own configuration during the fight (speed, height, throttle settings, etc), let alone what the other guy was doing. Even if one aircraft type consistently outperformed another on a certain aspect during combat, the reason might very well still lie with better tactics rather than a true performance advantage.

I say the above with utmost respect to fighter pilots with whom I have also worked extensively. I have seen clearly inferior aircraft consistently beat superior aircraft in mock combat when the pilot in the inferior aircraft was experienced, especially when he was experienced in both types. An example that I have seen with my own eyes were fights between fighter trainers and front-line fighters, where instructors in the trainers could consistently give rookies in the front-line fighters a hard time. I bet some of those rookies were thinking to themselves that their mounts were not nearly as good as advertised, while in reality the instructors just understood better how to exploit the strengths and weaknesses of the two types.

Somewhere earlier in the thread I think Gaston referred to "canned tests". Yes, that is exactly what one has to do during flight tests to determine the true potential of the aircraft. The only way to really know is to isolate parameters one by one and then test them. Combat is not the time to measure what the aircraft can do - combat is the time to put that knowledge to use.

By the way, flight testing is about much more than performance - I have spent much more time on flying qualities and handling qualities testing than performance testing. Handling qualities are extremely important when the question comes up on whether you can consistently extract the maximum potential out of the aircraft. Yet, on gaming simulations the topic of handling qualities seldom come up as few people know how to measure and interpret them. Of course, these days even more time is spent on avionics and systems testing, but that is another topic.

A small final comment before I let you guys be. I honestly don't have the time or energy to comment on every point made by Gaston, but this one really stood out:
This is simply not true. There were many dogfights in WWII and many did indeed end up in horizontal combat. In fact, I bet the natural reaction when bounced is to turn. However, attacking from superior height was the preferred method for just about everyone and it remains so today. Horizontal combat (in fact, dogfighting in general) is always a gamble - you may or may not win depending on the relative skill of your oponent. Attacking from superior height gives the attacker an "unfair" advantage, even if he has an inferior aircraft. Entering a fight with the plan to immediately enter horizontal combat is never a good idea. Only once the fight developes into a dogfight might a pilot with an aircraft with known good turning performance prefer to stay in the horizontal. The most consistent results always came from attacking using an energy advantage (height or speed) and then to get the victim on the first pass, ideally without him ever seeing you and without letting a "dogfight" develop - and this is exactly what accounted for the majority of aerial kills in WWII.

Oryx: Agreed, that comment does stand out and it's in stark contrast to any volume of reading on WWII air combat on nearly all fronts of the war.

I love this quote from a Russian pilot in particular:
http://mig3.sovietwarplanes.com/pilo...in/zyvagin.htm

This would not be an isolated comment either. It's not to say that dogfights didn't happen but they are much romanticized I think.

Holy Crow! A WWII pilot quote not being taken out of context or otherwise misused!

Aerodynamics as a science explains the flight characteristics of any aircraft with excellent precision.

Simulators are a different thing. Not only is the performance and handling characteristics always an approximation to some degree, the amount of things simulated may affect the actual combat performance of the aircraft.

For example, if you choose to fly with wonderwoman view, the visibility (cockpit design) ceases to be a factor, which gives a lot of advantage to planes such as F4U, Bf-109, and many others. When you restrict views to cockpit view only, planes with better visibility suddenly become a lot more effective in combat because the pilot can maintain their situational awareness better.

This is an example of a factor affecting combat performance in simulator, without having any difference in hard aerodynamic performance.

Similar example would be the thing I mentioned earlier: Handling qualities, control forces required to maneuver the aircraft, things that the simulation can only approximate to some degree based on some data. How hard can a pilot deflect ailerons in A6M Zero flying at 500 km/h? How hard is it to actually turn a Bf-109 diving at 650 km/h?

In other words, while simulators can usually be very accurate with the aerodynamic performance modeling, the combat performance of aircraft in virtual sky doesn't necessarily fully take into account the other things that were a definite factor in real life. Pilot skill, physical condition, fatigue level, tactical situation in majority of engagements, tactics that are used, fabrication differences between individual planes, visibility from the cockpit - none of this is usually even discussed when we're comparing aircraft performance.


The notion that any combat pilot with any practical experience (bar the very beginning of the war) would have voluntarily offered fight in horizontal plane if their plane was faster than the other is quite amusing. Even if your plane has better turn radius and turn rate, you would still want to retain all the energy you can in case the bandit's friends pop up when you're working on them.

Losing your energy puts you in more vulnerable position, no matter what your aircraft can do.

Actually, in the interview over Kuban, not once does he mention he actually intentionally put his aircraft on the six of an enemy, rather they seemed to fly into his gun-sight.




.

Oleg did model stick forces along with trim. IL2 pilots are restricted to 20 kg strength for game considerations, possibly because fatigue modeling was too much code. The IL-2 stick interface is strength based, how far you move your joystick modified by your stick settings says how much strength the virtual pilot applies to the virtual stick. And trim affects the virtual back forces (from control surfaces) that IL-2 does model. Oleg having been a test pilot did have ideas he wanted in his sim.

How come then most of the time they did dogfight, and even more so if they were flying a P-47D or a FW-190A?

When they avoided dogfights was when they flew Spitfires... I've never seen any aircraft type that avoided dogfighting as consistently as the Spitfire...

In fact the avoidance of dogfighting by the late Spitfire marks is so consistent and so extreme I had a hard time believing it, thinking as I was that the weakness of guns forced turnfighting even on 1944 pilots: Because only 2% of shots are on target, the target has to be peppered for a sustained time to be brought down, which doesn't help diving and zooming...

It turns out the Spitfire's 20 mm are really long-range and powerful, and allows the Spitfire to avoid turnfighting where it is at a disadvantage compared to most types, except the Me-109G or P-51 which are roughly equal or slightly inferior to it...




The Me-109G easily out-turns the FW-190 in unsustained high speed high G turns, despite much heavier elevator controls (which the trim does lighten, but not that much).

Same with the P-51 vs the P-47D, despite the P-47 having much lighter high speed elevator controls and the P-51 being described "as a real two-hander"...

So heavier controls are here inversely related to high-speed turn performance... Just because it is counter-intuitive doesn't mean our eyes have to be glued shut to what actually happens...

The FW-190A easily out-turns the Me-109G at low speeds sustained turns despite a much higher wingloading...

My theory explains perfectly well why those counter-intuitive things are the way they are.... And that includes how reducing the throttle reduces the wingloading...



Even at high speeds the pilot strength differences would actually be small compared to the enormous leverage forces acting on the aircraft, which actuall pre-determines what the pilot's strength actually is... In many cases the lightness of controls still results in poor high speed performance, which means the available leverage is sometimes way beyond what the airframe can do... It is leverages that matter, not pilot strength...

At high speed in a FW-190A, it might have better paid to have a light perceptive touch to avoid having the aircraft drop a wing or slip tail forward, if the aircraft's high speed turn/dive pull-out performance had not been so poor...

However the constant vibration in the FW-190A's control collumn killed the pilot's hand sensitivity to pressure anyway (like in the controls in the Black Hawk helicopter today), and this happened to a more or lesser extent on many types, and so the fine touch was just not available to a FW-190A pilot hoping to survive on this delicate touch at high speed: Better to fly at low speeds where the aircraft performance was far more capable of compensating the numb hands of the pilot...

Well if they are so well documented, can you point me to the actual wing bending tests made during flight of WWII fighters aircrafts?

As far as I know nada... And if they had done any, the relationship between engine power and wingloading would be well established: The fact that it isn't shows it was never done in flight on big-engined nose-driven low-wing monoplane types...

How come then the Me-109G is always out-turned by everything in sustained turns (except sometimes the P-51), unless it drops its throttle?

How come Rechlin test conclusions are the opposite for the horizontal plane, and general pilot opinion, both friend and enemy, was usually the complete opposite?

And how come KG 200 unequivocally states "The P-47D (Razorback needle prop) out-turns our Bf-109G"?

And when they don't bother specifying the "turn", is intended to mean sustained low-speed, not short-lived high speed, where the term "radius" is used instead...

You just have to close your eyes on a lot to cling to more intuitively easy concepts.

More often than not, reality defeats intuitively easy ideas...

Gaston

And this, ladies and gentleman, is why I and most other aeronautical engineers stopped posting on these forums.

Wing loading is measured in kg/m^2 - it is mass divided by area, not force divided by area. Unless you live in a different universe than us, throttle setting cannot change either the mass of the aircraft or the area of the wing.

There is no point trying to argue with you. You will believe what you want to believe, make up your own version of physics as required and suck random statistics out of your thumb - whatever. I have made my two posts for the decade.

How come then most of the time they did dogfight, and even more so if they were flying a P-47D or a FW-190A?

"When they avoided dogfights was when they flew Spitfires... I've never seen any aircraft type that avoided dogfighting as consistently as the Spitfire...

In fact the avoidance of dogfighting by the late Spitfire marks is so consistent and so extreme I had a hard time believing it, thinking as I was that the weakness of guns forced turnfighting even on 1944 pilots: Because only 2% of shots are on target, the target has to be peppered for a sustained time to be brought down, which doesn't help diving and zooming...

It turns out the Spitfire's 20 mm are really long-range and powerful, and allows the Spitfire to avoid turnfighting where it is at a disadvantage compared to most types, except the Me-109G or P-51 which are roughly equal or slightly inferior to it..."



Gaston, I begin to wonder if you actually comprehend the difference between what people do in the real world, and what people do in simulations. No one in their right mind is going to chance their future on the outcome of a sustained dogfight with an unknown enemy - unless forced to by circumstance. Combat pilots aren't there to test the capabilities of their aircraft or match their skills against those of the enemy. Their job is simple, it is to destroy the enemy as quickly and safely as they can. All sorts of crazy stuff may happen in war comics and movies but in real life where real ammunition is being used (by both sides) that sort of stuff is a no no. Get yourself into a sustained turn-fight with another aircraft and in all probability someone else, someone you haven't seen, will end the fight for you.

Wouldn't weight be effected by mass + G-loading with is dependent on AOA, coupled with speed, which is controlled by throttle setting ?

Something a pilot would know instinctively.. ;)

Edt: Terminology correction.. 'Mass effect' not being consistent as weight changes. :) =>> Wing loading = Force / wing area (for want of a basic formula)

No, mass does not change with g. Weight does.

Ja, you're right.. Sorry, I forgot for a moment :oops:

I got a bit curious seeing that we're on about the Spit-vs-FW190. decided to have a look at the specs on wiki (if you can trust such a source - no smoke without a fire)

2 specs I find interesting are loaded weight and max takeoff weight. In both case on wiki, the Spits (Vb and XIV) loaded weight is only around 250Kgs below max takeoff weight. whereas the FW (A8 and D9) is a whopping 500Kgs. This is for a heavier aircraft with a weaker engine ??

This make me think that the Spit when loaded is simply flying closer to it's limit of staying in the air, than the FW even with it's higher wing loading. Which might encourage Spit pilots not to get happy about tight dogfights and rather use hit and run, which seemed to be the norm in the latter part of the war.

Something to think about ;)

Maximum take off weight has nothing to do with the ability of the plane to 'just stay in the air'.

Additionally, figures on wikipedia are wrong, for instance loaded weight (8488 lbs) is used for the stated Spitfire XIV maximum take off weight (9278 lbs with 90 gal drop tank).

You'll find an airline pilot will not take off if his a/c is too heavy (close or beyond recommended takeoff weight)... there must be a reason for this. ;)

Yes, there is. In fact there are several.

If you don't take into consideration what the takeoff speeds, runway lengths and air density are then you won't get much out of takeoff weights.

It's like when The Joke would say that more weight on a plane makes the plane faster because hang gliders fly faster with ballast. Yes the gliders do, because if they don't fly faster they will stall when the unballasted, slower glider is still not stalled.
But -powered- airplanes don't get their energy from their weight, they can go faster using the spinny thing up front. More weight just makes their wings have more drag, which BTW is not proportional to wing loading.

Well, that all gets really complicated really fast.

Let's compare two aircraft of roughly same engine power, mass, and wing chord profile - only difference being that the other one has more wing area; for the sake of exercise let's keep the wing's aspect ratio also same, ie. chord length increase is proportionally same as wing span increase.

An aircraft with smaller wings has less parasitic drag.

But it has higher wing loading, which means at the same speed it has to use higher angle of attack, which increases the drag.

Both aircraft, however, have a certain optimal angle of attack at which the wing produces the least amount of drag.

Then, their optimal cruise speed is when they are flying at exactly this angle of attack, and the lift is exactly enough to counter the aircraft's weight.


For the aircraft with smaller wing, this optimal cruise speed will be higher than the aircraft with larger wing. What this means is, basically, that the smaller wing aircraft is better optimized for high speed flight and will achieve better efficiency when flown at higher speeds... and will reach higher top speed at level flight with the same thrust output from the engine!

That last part is actually pretty elementary physics. The top speed of any object is achieved when the power output equals friction/drag losses.

When the power output remains constant but drag coefficient reduces, then the drag losses are equalized at higher velocity.



However, things change drastically when these aircraft are compared in high angle of attack situation. At same angle of attack, the aircraft with larger wing will produce more lift and therefore turn better. There are also other, secondary effects such as better acceleration and better climb rate, which both very much explain why lower wing loading typically makes "dogfighting" easier compared to planes with high wing loading.

This does not necessarily correlate with combat effectiveness of the aircraft. The benefits gained in "angles maneuvers" are lost on energy maneuvers. The aircraft with smaller wing will accelerate faster in a dive, it will have higher dive speed limits, it will be more stable at high speeds, and it will lose less energy at dives and zoom climbs as long as angle of attack is reasonably small.


Of course, this is idealized comparison. There are not many examples where these conditions apply. One example that comes to mind is Ta-152C vs Ta-152H-1. In this case, the Ta-152C had smaller wing and Ta-152H-1 had larger wing. However these aircraft differed in other ways; Ta-152C used the DB603LA engine, whereas the Ta-152H-1 used Jumo 213E engine. Additionally the H model's long wing had much higher aspect ratio and thus was better optimized for high altitude flight due to lower induced drag, which is a different form of drag than parasitic drag...


However, comparison of these aircraft in IL-2 largely corresponds to what I just said. The Ta-152 H-1 accelerates better, climbs better, turns better, and at high altitudes it performs quite a bit better.

The Ta-152C has pitiable acceleration and climb rate, turns like a hippo in a bath tub, and top speed is puzzlingly low (I have some suspicions regarding the DB-603 engine model), but it definitely has higher dive speed, dive acceleration, and it retains energy quite well once you get it really going. It also offers excellent stability.

Which is a better airplane would depend entirely on what you were doing and how.



Wing loading of aircraft varies with g-loading, but typically it's expressed in level flight (1g acceleration), where it can be expressed in mass/wing area which colloquially is understood much better by people, than the actual implications of "wing loading".

If you REALLY want to get into it, wing loading is actually expressed in units of pressure. It is, quite simply, the aerodynamic lift force produced by the wing, divided by the area of the wing.

What does this means from the aerodynamic perspective?


As an aerofoil passes through air, it basically does work on the airflow to create pressure differential between upside and downside of the wing. These pressure differentials generate the lift that is used to counter the aircraft's weight.

The pressure differential is not constant over the wing; at some places it's higher, at the edges it's lower. However, if we were to average the pressure differential over the wing, it would turn out to be exactly the same as wing loading: Force of aircraft's weight, over the surface of the wing.

Why then is smaller wing loading preferable? Because the smaller wing loading means your wing needs to create less pressure differential.

Less pressure differential means less work done by the wing on the airflow - which, incidentally, is one source of drag in airplanes.


This is, of course, quite a bit simplified and it would be better to draw an image but I see this represented very, very well in IL-2. FW-190 included.

And then they both pull and hold a hard turn. Which one reaches stall first?

The stall speed multiplies by the square root of G's pulled resulting in a greater difference between the planes -- from high speed start it will be the one that runs out of smash first.

However the claim that a 190 should out-turn a Spit at low speed fails right there as you would have to defy physics or have a very poor Spit pilot in the Spit and a very good 190 pilot in the 190 to do so and then we are no longer comparing just the planes.
Take away knowing who is flying which plane (and most other details) and we have a war story to misuse and come up with ignorance-based 'data'.

The real cool stuff happens at higher speeds where turn fighters can't turn so hard without losing speed. The best energy fighting tactics use that whether online or IRL, check with Robert Shaw if you think different. At speed the 190A is booja but then 'at speed' in a 190A is 'high speed' in a Spit V.

I'm not sure if he's saying the FW190 doesn't turn well enough or if it turns too well.http://www.rxor.info/01.jpghttp://www.rxor.info/22.jpghttp://www.rxor.info/8.jpghttp://www.rxor.info/03.jpghttp://www.rxor.info/23.jpghttp://www.ryzu.info/9.jpg

Herra didn't make that claim of 190 being a great low speed turnfighter.
Gaston did. That's what "The claim" refers to.

They both reach stall at the same angle of attack (assuming, as with earlier premises, that the wing chord profile is the same and only difference is wing area). There is not such thing as "stall speed".

However: If starting airspeed is the same, and both aircraft start turning on the exact same trajectory - same turn rate, same turn radius, then the following applies:

Both aircraft need equal amount of lift to stay on equal trajectory.

As velocity is the same initially, and the only difference on planes is wing area, that means angle of attack must be different between the planes.

That means that the aircraft with smaller wing must hold higher angle of attack to travel on the same path than the larger wing aircraft.

This will, of course, quite fast start making a difference on where on the path the airplanes are. Because the small-winged aircraft needs to pull higher AoA to stay with the other version, it ends up having much more drag, and assuming both planes are having their engines balls to the wall that means the small wing aircraft will start losing energy in the turn much faster than the large winged aircraft.

As the small winged aircraft starts losing speed, it also starts losing lift and thus turning ability, and it needs to start pulling even more angle of attack until critical angle of attack is reached.

In this exercise, it is fairly likely that the aircraft with smaller wing will reach its critical angle of attack first if it tries to stay turning with the other aircraft.

Additionally, if we are to assume that the large wing aircraft starts pulling the turn exactly at the critical angle of attack to begin with, then it is quite impossible for the small wing aircraft to even stay with it on the turn, because it cannot increase its own angle of attack higher than the critical AoA, and stalls immediately at the beginning of the turn - or ends up on a wider turn than the large-wing aircraft.

This, personally, I can confirm with great satisfaction in IL-2.


Did I mention that the concept of "stall speed" is something I personally find rather annoying?

Stall speed is an indicatory value for pilots and only holds at level flight. Aircraft can stall at any speed when thrown around with fists of ham.

Stall speeds are given as the speed at which the aircraft can JUST hold its own weight with its lift, without losing or gaining altitude or airspeed, and holding angle of attack at or very near critical AoA.

It gives some idea of the aircraft's performance since the stall speeds can be compared, however its relation to turning performance is not necessarily 1:1.


Amen.

However we can probably both agree that as the FW-190 was introduced it had great successes against the contemporary Spitfires for various reasons, which could be listed but have already been mentioned in the thread.

"Better turning ability" is decidedly not one of them, but the otheres - higher speed, excellent visibility, easy operation of engine to get the most out of it (Kommandogerät love) while Spit pilots had to dick around with engine settings... All of these could easily have made plausible situations where a FW-190 (or entire group of them) "outmaneuvered" Spitfires, using energy tactics, team tactics, and surprise of Spit pilots at finding entirely new aircraft that they've never seen before.

Yeah, at transient turns (rather than sustained turns) there are some different factors to consider. An aircraft's transient turn rate basically depends on how fast it can dump energy into direction change, whereas sustained turn rate depends on how fast the engine can produce energy to compensate for drag losses, keeping the airspeed constant (and with that, turn rate and turn radius).

Thank you Herra!

I like stall speed as an aggregate measure of a number of factors when the plane is in flight at critical angle. I can predict that in a 4 G turn it will reach stall at 2x stall speed if piloted perfectly. And I think the neat part is that would be 2x clean stall or 2x dirty stall depending on configuration.

Of course piloting can change that but never for the better.

One thing though. In the turn where the smaller wing version of our plane is experiencing higher drag and slowing down at a greater rate, the very act of slowing down does tend to reduce turn radius so there's some ratio of lost lift widening the turn to lost speed tightening the turn, the path is not simply the rate so in my view...

If both start -above- corner speed then for a time the ratio might benefit the higher wing loaded variant. And I think that's where high speed turn performance maybe delivers a bit more.

As you say, it gets complicated. :)

IMO the place the higher wingload plane will get the biggest advantage is combining high speed and the vertical. That's where the FW's have been best for me.

So nobody has come up with prop fighter wing bending data during turns so far... Why am I not surprised?

Nobody has come up either with one example of Spitfire out-turning the FW-190A in low speed sustained turns: There is quite a few accounts clearly demonstrating the opposite, with one pilot stating this was a general fact... Quite a discrete 60% advantage let me tell you!

"Il-2 confirms with great satisfaction"

But what about the satisfaction of a real wartime FW-190A-8 Western Front ace?

The only time I ever heard a real WWII German ace directly opining on a simulation forum was through a relative on the Aces High "vehicles forum" around 2005, a Western Front FW-190A ace who unfortunately was not identified by the relative posting his replies to queries, because I suppose there were P-51s being shot down in his accounts, (a rotten deal for making my case at any rate)...

A lot of about the way the posting relative presented his comments made it clear he was in contact with the real deal... He mentionned 3 separate types of aileron chords being available as an offered pilot "option" on the A-8, the widest chord being picked by the ace in question to help "catch" the wingdrop during low-speed turns... He described increasing further the "chord" of the ailerons by adding field-mounted "spacers" on the aileron hinges to increase their effectiveness at "catching" the wing drop, riding the turn on deflected ailerons (He describes precisely relaxing the pull on the stick just as the ailerons are deflected to catch the wing drop)...

He described reversed a tailing P-51D in this manner using just two 360° turns flat on the ground (the P-51 straining very near its stall all the way)...

He described the huge advantage of the broad wood prop, but also the risk of hitting the ground with it on landing (not clear if that was much greater than with the narrow metal prop)...

He described using the FW-190A-8 exclusively as a low-speed turnfighter, reducing the throttle and dropping the flaps before a merge with faster P-51s... He did not care about their greater speed because he could turn to go head-to-head with them if they did not stay with him... Head-to-head was apparently a big advantage for the FW-190A, so the P-51 was presumably just as well off dropping the throttle and turning as well...

The remarkable thing is, I have never heard of such details anywhere else, and yet nothing of the aileron details and other issues has ever been challenged as being false...

I have asked years later of the site owner, surnamed Hitech, to tell me where to find this thread, titled "FW-190A veteran experience" (it went on for about 4 pages the last time I saw it): He actually claimed not to remember it... It is of course deleted from the archives, and he knows nothing about it...

I guess everything the "real deal" had to say just exposed too harshly how current simulations, his and others, were a big pile of claptrap...

But apparently, after all my threads, the Aces high FW-190A got quite a bit better... :D

Gaston

Another 2c worth as we're on a roll.

The Spit wing is narrow in thickness and long in chord, designed for speed.
Take this to low speeds

If you rotate the spit the chord length now presents a larger area for drag (but producing momentary better lift) compared to the shorter chord of the FW, which has a thicker wing producing better lift and less(or equal) drag than the spit for the same rotation over longer time. Not forgetting the FW weight, but it's further from it's takeoff weight (Yes.. we're now in this region as I hinted before) than the spit, so it can probably be pulled harder.

The thing in the spits advantage is it's power-to-weight ratio which could help it in the climbing turn, but is an inline engine more advantaged against a radial at low speeds. From what I can see and have read, the inline is a bugger to control at low speeds.

I'm willing to take a bet that the Spit had very little advantage (if any) over the FW and such low speeds, which would account for Gastons 'research results'

Your turn ;)

http://www.austria-lustenau.info/for...s/facepalm.gif

Just for giggles:

"I...stall-turned to port to attack the rear two Fw 190's. They broke and turned with me but I could easily out-turn them..."

Spit IX vs. Fw 190. I actually looked for two minutes, found more than you in fifteen years.

At 10K plus .. YOU must be joking... and no mention of speed...
Sorry .. disqualified for the current argument ;)

Take it down to stall and lose your bet.

Your 'givens' about the Spitfire are wrong. Why not just say the Spitfire won because it bestowed 'gifts' upon the British pilots, or some other statement made from denial?

I've been around for a lot lonnnger ;)

Please keep going Gaston, I've never laughed so hard about an FM girlie fight in my entire time with IL2.

Just remember, if you keep repeating untruths enough people will grow tired and leave the discussion and you can claim a "win".

It's called the "big lie", and it was invented by the Germans as well...

I actually was expecting Gaston to post the lame excuse of whatever kind. 3000m is too high because...? Speed mentioned in all the infinite number of accounts Gaston tells us he's heard someone tell who's read it somewhere on the internet is what?

FYI, a :wink: doesn't make posting nonsense any more bearable. You'd be better of asking questions.

I wasn't talking to you, and I don't care. :)

You sound like the PR guy sending the 8th or any fighter command to Germany 1943-5.. I'm sure they just loved you :grin:

JtD...
It seems like Gaston has done a few years of research into combat reports (if he claims right), maybe on a project of sorts.

Aerodynamics and models are accurate, no doubt to a certain %, but have they been verified under certain and specific conditions.
For the aircraft under question, most likely not, considering the conditions of the time. That leaves us with what... theoretical values, or 'real experiences'.

Every research into the past relies on Current Knowledge and Statistics. Gaston is the Statistics of this research.
What aerodynamic proponents are arguing are static test results, if you can call them that, and not dynamic as they quiet simply do not have the same aircraft in question.

;)

Must be the worst research I have ever seen. None of his claims stacks up and he will not tell us where in the 'research' the evidence supports his claim.

You must have missed it... :cool:
You must also clarify his claim ?

Every one of his claims have been shot down multiple times on presentation, that's a fact.

Both of you have weird ideas on how much is not known and fail to acknowledge not only how much is known but the nature of that knowledge. But then both of you live in special worlds where physics is only what you choose to understand. Nothing is true until you make the mistake of admitting it. :rolleyes:

JTD can in 2 minutes find multiple accounts of what Gaston swears there are none.
To which your answer is that you have been around longer than that.
Yeah, you really showed HIM!

Yeah, and those reports are not relevant to the envelope Gaston is talking about.. You really showed us haven't you !! ;)

A matter of fact that none of you have come up with a decent counter argument, or proof therof, beyond reasonable doubt that Gaston is talking tripe.
You all revert back to aerodynamic formulae and charts, most of which are from pilots that you wish to discredit, so where does that leave your argument.
While aerodynamics does play a significant role, most of you are not willing to remotely admit that there might be a problem with the data, in the area that is in discussion.

If I were a test pilot, I'll be crying with laughter.

K_Freddie, over the years I've brought up dozens of arguments. All of which were chosen to be ignored. Why should I bother to continue a discussion that in fact is just a monologue by someone to justify an alternate reality?

Again, why does a turn-fight at 3000m not count? Other than it not suiting the theory.

Same reason why Gaston's claptrap fails, lack of full information.

In the meantime Freddie has joined Gaston in claiming that none of their BS has ever been shown false. It goes along with Gaston claiming that there is no historic information that counters his view. They have 2 standards and the old crank-loser's tactic of waiting months or longer after getting beat; put the same BS up again as if nothing happened before.

I see "wing bending" getting dragged in again. Please, QUALIFY THAT!

How many remember the "stress risers" championed by Gaston in post after post. Not a solid value to any of it and then the term got looked up. Gaston pushed a non-applicable term that has NOTHING TO DO with aerodynamics as if it does, complete with BS diagrams that NEVER QUANTIFIED A THING as some magical force that keeps planes from turning. Oh yeah, he really knows his BS and at least one player not only eats it but says how good it tastes!

FW190's have higher stall speeds than Spitfires. No amount of playing with partial factors and effects changes that. If -ignorance- was all you need to fly then those two would be posing for photos by the Mars Rover.

There is plenty of information. Much of it is speculative, subjective and very selective.

Full information allows repeat of the event without choosing one of many possible widely different interpretations.

Indeed

Interestingly I have not gone back to aerodynamic formula or charts. All I have done is go back to what Gaston has put forward as his evidence and offerred to debate his theory using the data that he claims supports his theory.
It is notable that he has not taken up that challange. The question I put to you is why hasn't he taken up the offer which is more than fair.

Just to remind you. He has said that 95% of all combats involve sustained turn and that the combat reports support this statement.
My challange is that he picks any combat report, from any of the lists of combat reports and we will analyse the ten either side of the report that he has chosen and see the percentage.

Why do you think he hasn't taken up that offer. Or indeed can you see what is wrong with that offer

I await your observation with interest

Personally, I found that flying sims, once I got past rookie level, gave me a lot of insight into what many combat stories and Robert Shaw were saying.

When you include superior energy and tactics, like what accounts of FW-190's vs Spitfire V's over the channel tell, even EAW delivers.

But don't just take my word for the modeling in IL-2 when there's been a whole trail of aerobatics pilots and at least one test pilot say it's good.

The actual historic test data of the real FW's have been used is both table-driven and model-driven flight sims (as opposed to arcade games) and the FW's behave pretty much the same on turning, they won't turn inside Spits with both planes at low speed and co-alt but they will at higher speed, see IL2Compare for an idea where.

Look up clean stall speeds; FW at 110 mph to 130 mph and Spitfires at 80 mph to 95 mph. Spits have the power to sustain over 3 G's, I expect the FW to be in the same range but have to be faster to do it *or* simply use the vertical and occasionally be able to pull lead instead of the constant lead you can hold when turning inside a target. You don't have to have the better turning plane to get inside a target, you just need more energy.

K Freddie
I am still awaiting your views as to why Gaston refuses to debate his theory using the evidence that he says supports his case.

I have yet to understand why wing bending would significantly affect the turn capabilities of these aircraft. It's like saying you can't measure a flag pole's height by putting it flat on the ground, because then you're measuring its length instead...

Logical parse-errors aside, what I can glean from the thread is as follows:

Apparently, Gaston's claim is that since no wing bending tests have been done to measure dynamic wing loading on these aircraft, we can't make accurate predictions about their turn performance.

However, the fact of the matter is this:

-Wing bending can not decrease the aircraft's mass.
-Wing bending can not increase the maximum lift produced by the wing.

Latter point can be proven by

a) assuming that the wings do not deform significantly when aircraft is flown within the flight envelope (and over-g tends to permanently deform the airframe, often fatally)

and

b) in a dihedral setup of wings, when the wings bend upwards under load, the lift can only decrease as the total wing span decreases.


Since the aircraft's weight is not affected by any wing deformations (how could it?) and the wing deformations cannot significantly alter the lift capabilities of the wing to positive direction, it naturally follows that wing bending does not have significant effect on the aircraft's lift to weight ratio at different angles of attack.

A simple fact of rotational physics is that for an object to stay on a circular path, a centripetal force (lift) is required to accelerate (g-forces) the object's mass towards the centre of the circular path.

The equation for this force is simply F = ma and no nonsense about wing bending will change the fact that you need certain amount of LIFT to turn an aircraft of certain MASS at a certain rate and turn radius.

You can increase turn rate and decrease turn radius by either increasing lift, or decreasing mass. I think we can all agree that the weights of WW2 aircraft are fairly well documented, so this entire argument can be condensed to the following statement:

Gaston's claim is that the FW-190 Anton models produced significantly more lift than aerodynamical models and testing suggest, especially on low speeds (which, incidentally, is where any wing provides the least lift, if you know anything about aerodynamics).

What this magic mechanism would be, he neglects to comment on. The problem, here, is that aerodynamics is a very well documented science and going against it would require a bit more than cherry-picked pilot reports interpreted with a hefty bit of bias.

Additionally - and even more confusingly - since Gaston's claim is that this magical increase in lift at low speeds would have made the FW-190 a better low speed turn fighter than Spitfires and Bf-109's, it logically follows that this magic lift increase would not appear on other contemporary aircraft which the FW-190 is compared to.

Which, I need to impress, were not fundamentally different from the FW-190 regarding their wing profile. In fact majority of the WW2 fighter aircraft used vastly similar wing chord profiles, which shouldn't be a surprise to anyone who is familiar with the term "convergent evolution" - there were certain key designs that were used by almost everyone because they were the best, and most successful. The FW-190 was an advanced design, but it did not include Haunebu technology or any other occult magic to match it to anyone's interpretation of what its capabilities were.

It was a machine of finite, and variable capabilities, and the pilots who flew it and survived were capable of making it perform to its best. At certain flight envelopes, at certain times of the war, it would definitely outperform, outfly, even out-turn its adversaries. But a blanket statement that FW-190 Anton series were better at sustained low speed turns than Spitfires defies any logic and the combined might of applied sciences.

But if there's something I've learned in my time on the Internet, it is that you cannot change the mind of a true believer. The best you can hope for is to prevent them from converting others, and the way you do this is to expose their claims for the baloney they are.


Overall, this conversation should be analyzed with the help of this little video:

http://www.youtube.com/watch?v=eUB4j0n2UDU

I believe that those who 'get it' will understand and be better at flying and combat whether virtual or real while those who don't will be finding fault with whatever doesn't meet their poorly founded expectations.

Learn the differences in planes, put them into practice, and those war stories will become more clear and less a puzzle to be re-arranged to spell out how really little you understand.

Your comments show little understanding of what I said.

I said the wings on these old aircrafts ALWAYS bend more than previously assumed for a given horizontal turn, since wind tunnels do not imitate a curved trajectory, and wing bending on these old nose-pulled types was never actually measured in turning flight (dive pull-outs measurements would not count because of the prop unloading in the dive)...

The structural limit before permanent deformation on these fighters was typically a factor of two, so way beyond the assumed loads: 14 Gs on the Me-109G and 13 Gs on the P-51, so there is plenty of room for the structure to bend more than the assumed 6 or 7 Gs of assumed actual wing bending load.

If you don't understand that more wing-bending applied differently among types can play havoc with wingloading assumptions, and is important for the wingload hierarchy between aircrafts, I don't know what to say to that... Your comment makes absolutely no sense.

Even Glider would readily agree that if the wingload is added to unevenly across types, it would change the wingload hierarchy between types, which is what this is all about...

Your comment that weight cannot be added to just because an object is in flight seems on its face nonsensical: If I press down, say through leverage, with a fifty pound force on an 80 lbs block, flying or not, it will then become (for all practical purposes) 30 lbs "heavier" than the "heavier" 100 pound block, flying or not... I cannot fanthom what you fail to get in this...

I never said the FW-190A produces more lift at lower speeds and lower Gs than at higher speeds and higher Gs: I said that the "extra" load is proportionately greater at lower Gs, because it is not changed by speed but by power, and the power stays the same since it is assumed to be at the same maximum in all turns, high or low G, for simplicity's sake...

So it is logical that an aircraft that has less of that "extra" power load (because of better leverage over a shorter nose) will benefit more at low speeds where the power is "larger" compared to the "pure weight" G loads... But at high G loads the actual mass of the aircraft is multiplied by the Gs, while the power is assumed the same, so the lighter aircraft benefits more than the heavier aircraft from high Gs, and the "power leverage load" is proportionately smaller to the "real" G load, so having a big advantage in "leverage power load" (like the FW-190) is less significant and becomes less and less significant as the turn becomes more and more tight beyond what is sustainable in speed...

At high Gs, weight matters increasingly more than power, everyone should be able to understand that... Hence the FW-190A's turn performance goes down relative to lighter fighters when Gs go up beyond a sustainable speed... Which is exactly what can be observed in innumerable combats...

There is no way, if you accept the premise of an extra load on the wing due to power, that any of this is debatable...

As for the issue of where the extra lift comes from, it is a thorny issue, but since we don't know how much those wing actually bend in turning flight (thus with assymetrical air inflow), who can say the extra lift is not there?

If there is extra wing bending, and if it changes with power level, then it means that the extra lift is there, and it is power-related, regardless of what our other assumtions are...

Note that I attribute the load to the leverage of the power coming from a long nose, so that is why more recent studies of very advanced jet fighters completely failed to uncover this extra power load... The existence of such in-flight wing bending tests seems not to overlap further back than the early jet age... Current warbird operators do not use wing strain gauges in flight, at least not routinely...

I also think that one of the features of that extra "nose power" load is that the width of the prop surface creates its turn assymetry through increased thrust in the disc's inside turn half, which increased thrust could help "mask" the inevitable extra drag needed for that extra load on the wings...

By saying "wing bending cannot create extra lift", you are confusing cause and effect... The cause of the extra lift is obviously complex if it was hidden for 100 years (but it isn't so outlandish if you include the "gradually increasing" assymetrical inflow of air in a turn, which is not duplicable in wind tunnels)...

In any case I'll be back: I am now compiling a list of P-47D combat reports to answer Glider's challenge. To be fair to him, the ratio of multiple 360 turns to dive followed by zoom seems more like 70-30 than the 90-10 I previously said, and it has to be added more than half of all the reports are a fairly meaningless jumble of actions, but I think Glider will find it hard to match the number of meaningful turn battles with an equal amount of dive and zoom, especially if dives followed by a long chase are excluded...

This compiling is very rewarding for me, as the accounts do clearly demonstrate the superiority, in low-speed turns at any altitudes, of both the P-47D and the FW-190A to the Me-109G (and the slight superiority of the FW-190A to the P-47D).

Gaston

No way you could pull anywhere near 14 Gs without wings coming off!

Weight or mass of object doesn't change in normal circumstances... only the fuel consumption changes it. When speed approaches the speed of light, only then mass goes infinite. Wasn't it Einstein who said something like that?

Too bad it doesn't actually prove anything, e.g. that Me-109G would really turn worse than a P-47D. In such fight, the 47 loses... most notably because it's heavier.

That's because your made-up nonsense cannot be understood in any logical sense.

SOURCE?

SOURCE?

And when did they put full size planes in WWII wind tunnels?

Ass-uming the pilot can take any 13 or 14 G's beyond momentarily, less than a second.

SOURCE?

Something besides in the mind of Gaston, please!

A new of line of unsupported BS?

Because it is complete physics-violating BS to say that you can from within the plane press down and make the plane heavier. You are now in the realm of violating the 2nd Law of Motion in Grand Crank Style. The classic non-demo is a 150 lb man pulling his bootstraps with 160 lbs force and expecting to lift himself off the ground.
Pressing down on a block that you are not standing on does not apply to pressing down on a plane by any means within the plane. That does not include changing the controls that affect air flow (external to the plane) which does not change the weight of the plane regardless.

Which is BS. Power/thrust does not change wingloading.

So given that physics is wrong and your joke ideas are right, you have a muddled 'point'.

Not you, that's for sure. How far the wings could cantilever without deforming was tested and known. They did test structures to destruction but then engineers did and still do things like that.

If... Enough ... nothing real, no source... Then It Means, whatever you decide in your fantasyland ... Other Assumptions and non-factors from non-facts....

What recent studies This Time? SOURCE?

And now you're back to the old "Stress Risers" without actually using the words This Time Around. But it's the same unsupported stuff as before.

What is your SOURCE? Do you hold a model plane and imagine this while making zoomy sounds?

Obviously. They could predict what happened quite well without knowing the secret Gaston Force that does absolutely NOTHING. Since it had NO EFFECT they never knew it wasn't there! Oh, those Idiots!

If your ideas were right then perpetual motion would be possible.

I will create a free-body diagram of the (relevant) forces affecting a flying aircraft in a turn when I have time for it.

I'll just note a few key factors here.

1. Maximum power of the engine is irrelevant at slow speeds.

If you were familiar with definitions of work and power you would understand this; I can show you why this is so but I don't know if you would understand the mathematics (it's reasonably simple but it does involve some grasp of differential calculus). For now, suffice to say that when an aircraft travels slower, the engines do less work per unit of time, which means by definition that their power output is reduced. Aircraft engines reach their peak power output only at maximum speed of the aircraft (same actually applies to automobiles!).

2. There is a component of thrust that is directed toward the centre of the turning circle.

This can easily be defined as

Fc = F * sin α

where F is the thrust of the propeller disk, and α is the angle of attack. Let's assume that α cannot be larger than critical angle of attack; α ≈ 15°

At critical angle of attack (maximum turn performance at any speed), the thrust toward the centre of the circle would be

Fc = F * sin 15° = 0.25 F

Hence, we can say that at most, only about quarter of the total thrust of the engine is directed inward and thus assisting in the turning radius. This, however, applies to all aircraft, not just FW-190 so it doesn't really help your point... especially as we get to point three.

3. Since we now know the assisting centripetal component of the thrust force, we can determine the assisting centripetal acceleration:

a = Fc / m = 0.25 F / m

since F/m is the thrust to mass ratio of any aircraft, we can DIRECTLY say that the thrust to mass (more commonly incorrectly expressed as thrust to weight ratio) does affect the turning performance.

Moreover, this simple exercise of physics shows us that aircraft turn harder when their engine produces more thrust.


Confusingly (or rather, not) we know that Spitfires have better acceleration and climb rate than FW-190, which means Spitfires have better thrust to mass ratio.

Which means that the expectation of the theory is that Spitfire engine can assist in turns more effectively than that of FW-190... which doesn't really help your case.


4. Quantitative analysis

How, then, does this centripetal acceleration produced by the engine thrust compare to the centripetal acceleration produced by the lift of the wings?

Well, again, simple exercise. If we assume that at certain speed v, the aircraft would be able to do a 3g turn, that means the wings produce enough force to produce 3 g's worth of acceleration (they can easily produce much, much more force up to the limit of their plasticity, in which they deform permanently, but since the discussion is about low speed performance let's keep it at that flight regime).

By contrast if we look at the maximum acceleration that the engine thrust can produce, we can immediately see that the thrust is about an order of magnitude smaller force than the lift of the wings. It's difficult to actually determine the thrust of these aircraft; however we can get some results by looking at how well they climb vertically. None of the WW2 aircraft can maintain their velocity (or increase it) in vertical climb; this means that the propellers produce less force than the aircraft's weight - their thrust/weight ratio is smaller than one.

At thrust/weight ratio of one, the engine could give the aircraft exactly 1g of acceleration. Since these aircraft get nowhere near that, let's be generous and assume the acceleration at standing start could be.. let's say 0.5 g's (it is probably less than this, but oh well...).

Now we can determine the centripetal acceleration by thrust:

ac = 0.25 a = 0.25 * 0.5 g = 0.125 g


What does this mean? Well, if a gliding aircraft at speed v can pull a 3g turn, with full power it could pull about 3.125 g turn (increasing it's turn rate and decreasing turn radius).

This applies to all powered aircraft, and the defining factor is the aircraft's thrust to mass ratio - or, unloaded acceleration by engine thrust alone.

Multiplying this by the sine of angle of attack you can directly get the assisting centripetal acceleration.

a(engine) = 0.125 g

a(lift) = 3 g

we can see that the assisting engine thrust is, at best, about 4% of the lift.

At high g-load the ratio further decreases because you can't pull critical angle of attack at high speeds - which means that most of the thrust is directed forward.


Now, if you're looking at two different planes with different thrust/mass ratios - yes, the plane with better thrust/mass ratio will provide more assisting centripetal acceleration.

However now you need to consider that the thrust/mass ratio of these aircraft had relatively small variations. What you will find is that the overwhelmingly deciding factor in turn rate is the lift/mass ratio rather than engine thrust. You might find small differences in the assisting thrust - let's say that one aircraft's engine might assist at 4% of lift, while another aircraft's engine might assist turning at 5% of the lift... but this would already mean a quite hefty 25% thrust/mass ratio difference!


Here we have shown that the engine thrust is primarily responsible for maintaining the cornering velocity (overcoming drag), and wings are primarily responsible for actually turning the aircraft.

I don't expect Gaston to really comprehend any of this, this is more for the benefit of others.

I'll make that free body diagram as soon as I can... now I must get going to school.

Toodles!

Please, post this on Aces High board, I'd like to read Dale's comment when he realize that his FM is "Gaston approved" :grin:
Structural limit for deformation is the one listed in manual, for fighter planes, safety factor was typically about 1.5 so plane with 8G limit will be expected to survive 12G. Between 8 and 12G plane will suffer permanent damage and in case of repeated over-stressing it will break even at values under 12G.
You can see in attachment where is the expected wing failure for one WWII fighter.

There is no aviation board where Gaston didn't post his alternative aerodynamics theories, if he was capable of learning anything he would learn it long ago. He is not even funny anymore, it's just sad.

This is entertaining. Even in college, I've never seen anyone who believes their own BS as much as Gaston.

http://www.matrixgames.com/forums/up...Crazy-1271.gif

Trolls...

Ah well, I remember having to give up on a mechanical science forum because of one of those.

He kept arguing that imperial measurements were far superior to metrics and people were foolish enough to argue with him.

There is only one response to Trolls: ignore them.

Here is some counseling:

http://www.wikihow.com/Recognize-a-T...n-the-Internet

http://trollpolice.com/trolls-and-cyberstalkers/

~S~

So Gaston, if I understand correctly, your theory is that these previously unnoticed and/or not measured and/or unmeasurable forces you describe are so significant that they make the P-47 and the 190 into good low-speed turners, even though all the known, measurable, and measured forces predict the opposite to be true. Correct?

Gaston
Please don't quote me as agreeing anything you say, without me first, actually agreeing.

No need to do vast research, just pick one combat report from any list and we will see what happens in the ten either side.

Nice, simple and easy for anyone to check.

I strongly suspect that you have not found a suitable example and are going to try and blind me and everyone else with vast amounts of data that will mean nothing

He's writing his own list with hand-picked examples (which will all appear to agree with him), he almost said as much in that post.

Based on criteria of fitting the hypothesis in some manner.

Don't say "any" list because you won't get just any list.

Just because there's accounts on a web site doesn't mean there's been no selection of which accounts are presented. Just for example: the pilots who did not come back did not make combat reports. That alone is data selection.