Roll rate P47 VS FW190

barney said:

No, I am thinking that in a defensive role you'd want the roll to be as fast as possible, remembering the pilot has to end the roll in the attitude he (mostly male pilots in the war) wishes to turn in. Then, in a coordinated effort, apply elevator to change direction. So, that, I believe, would be a snap roll.

How quickly the result of those two actions in combination move your aircraft out of the aggressor's windscreen, I'm suggesting, should determine the effectiveness of the planes abilities, not just roll alone.

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True.
the roll is used with a turn, however, a sharper turning plane that can't roll as fast as a slower turning plane will not be able to follow it through a roll maneuver. (manuever to include a turn even if its not the sharpest)

You have a spitfire that follows a P-47 into a dive. The P-47 banks and turns to the right, while the spitfire follows, and then the P-47 suddenly rolls the opposite way 180 degrees and turns. Rolling alone does nothing more than bank the plane, The plane is going to turn where ever the elevators pitch it towards. If the P-47 rolls 180 degrees where the spitfire has only rolled 100 degrees it won't be able to pitch its nose in the proper direction to follow.
I think the P-47, in contrast, was able to dive and make relatively quicker corrections in its path to the target because of its better high speed roll rate. In pursuit of a 109 that not only dove but banked and turned was probably easy pickins for a fast moving P-47.

There is a lot to be said about high speed and rate of roll considering that turn rate is limited by pilot threshold. It was quickly recognized in that higher rate of roll at high speeds was an imparitive characteristic of a jet fighter.

This is all very interesting. I am not a pilot, so forgive any ignorance. To me the roll rate is critical in defensive and offensive positions.

Lets put a the faster rolling P-47 on the tail of a Me 109 for instiance. Obviously the 109 can turn better. And the P-47 can equal the roll at its worst, and better the roll if the 109 is diving away to break contact as the airspeed builds which favors the 47.

The 109 pilot does a few rolls into turns, attempting to shake the P-47. But because the 47 can roll faster, as soon as the pilot sees the 109 reversing his roll, the 47 can roll quicker, and apply elevator to put his nose ahead of the 109 for a shot. If the turn is sustained, then the 47 is going to lose out, but if the 109 pilots keeps reversing rolls and turning opposite, he wont get away and most likely will have some .50 calibers in his tail feathers.

Good roll can be very handy in a defensive situation and will be important for good manoeuvrability of an aircraft. The 190 had light and responsive controls, good accelerations and instantaneous turn. Whatever your theories are on how a roll is or should be used in combat the fact remains that it was used effectively in both defensive and offensive flying by Fw 190s.

billswagger said:

perhaps that is where the myth is perpetuated. I just think that typical combat speeds were usually between 250-300IAS and any roll advantage would still be in an FW190s favor.

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Yes, but this is because the Fw-190 had an absolutely insane roll rate, not becuase the P-47 had a substandard one. The NACA chart really puts it into perspective- 190 degrees of roll at mid to high combat speeds is simply an order of magnitude above any other aircraft. Of course, it couldn't turn worth anything, but it's extreme roll rate meant it didn't have to.

MikeGazdik said:

This is all very interesting. I am not a pilot, so forgive any ingnorance. To me the roll rate is critical in defensive and offensive positions.

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You'd be 100% correct. Why? Because every single airal maneuver, save the loop, starts with a roll. A turn, a split-S, anything, you have to roll to put your lift vector in the right direction before you can go there.

The defensive scissors- a staple defensive maneuver where the defender starts flying a weaving pattern back and forth to get himself out of synch with the enemy- is dominated by roll rate. A slower-rolling fighter simply won't be able to follow the defender's weaves as fast, and pretty soon the serpentine path being flown will see the quicker-reversing fighter making slower forward progress (because he's weaving more often,) putting him behind the attacker for a kill. The use of the scissors in this fashion means that a fighter with good roll rate and good performance in one other area- such as climb, or speed- doesn't need to turn.

Demetrious said:

Yes, but this is because the Fw-190 had an absolutely insane roll rate, not becuase the P-47 had a substandard one. The NACA chart really puts it into perspective- 190 degrees of roll at mid to high combat speeds is simply an order of magnitude above any other aircraft. Of course, it couldn't turn worth anything, but it's extreme roll rate meant it didn't have to.



You'd be 100% correct. Why? Because every single airal maneuver, save the loop, starts with a roll. A turn, a split-S, anything, you have to roll to put your lift vector in the right direction before you can go there.

The defensive scissors- a staple defensive maneuver where the defender starts flying a weaving pattern back and forth to get himself out of synch with the enemy- is dominated by roll rate. A slower-rolling fighter simply won't be able to follow the defender's weaves as fast, and pretty soon the serpentine path being flown will see the quicker-reversing fighter making slower forward progress (because he's weaving more often,) putting him behind the attacker for a kill. The use of the scissors in this fashion means that a fighter with good roll rate and good performance in one other area- such as climb, or speed- doesn't need to turn.

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This will work only if the attacking aircraft will be foolish enough. A smart attacker could be able to defeat the scissors even with worse roll and kill the defending aircraft. That's how some P-47 and P-51 pilots defeated scissoring Fw 190s at speeds where 190s had the edge in roll and turn.

barney said:

No, I am thinking that in a defensive role you'd want the roll to be as fast as possible, remembering the pilot has to end the roll in the attitude he (mostly male pilots in the war) wishes to turn in. Then, in a coordinated effort, apply elevator to change direction. So, that, I believe, would be a snap roll.

How quickly the result of those two actions in combination move your aircraft out of the aggressor's windscreen, I'm suggesting, should determine the effectiveness of the planes abilities, not just roll alone.

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Barney, I think you're talking about a snap roll. Definitely a defensive act. Stick back, rudder over, Aircraft should snap over in the direction of the rudder, moving to the side. Moves faster if you go towards the side of the engine "on" torque (and the opposite holds true, or at least should, for engine "off" torque). But it happens so fast that engine speed is usually set through the manuver even if you increase throttle.

I'm not sure how adding the alerions would affect it. I think, never having done one with the alerions, it would make it a bit hairy. Stick back and in the corner, rudder to the side....hmmmmm.

One thing about the snap roll is it is not pretty or fun to do. It is quick and somewhat sloppy. Alerion rolls are much nicer. Can keep 1 g through the roll easily. Look nice too.

LWulf said:

This will work only if the attacking aircraft will be foolish enough. A smart attacker could be able to defeat the scissors even with worse roll and kill the defending aircraft. That's how some P-47 and P-51 pilots defeated scissoring Fw 190s at speeds where 190s had the edge in roll and turn.

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You defeat the scissors either by extending through with superior energy (say, if you'd missed a high-speed bounce and had plenty of smash to blow,) or by popping up into the vertical to stay behind him. However, this is best done if you're in a ship with a superior climb rate, because a smart defender will see you pop into the vertical and counter by going vertical himself, in which case the scissors will continue in the vertical. Then the fight has developed into the "rolling scissors:"



Just a note- both the P-47 and P-51 were superior to the Fw-190 in sustained turns, and I think both of them were better in instantaneous turns as well.

Doesn't the rolling scissors, if taken to the conclusion, end up in a decending spiral (all other factors being the same)? Never done one or been in one but I was told as much.

I'm under the impression that smart pilots of Boom Zoom aircraft like the Fw-190 don't make sustained turns. If your 4 x 2cm cannon miss then you use superior speed to extend away for another high speed pass.

Demetrious said:

You defeat the scissors either by extending through with superior energy (say, if you'd missed a high-speed bounce and had plenty of smash to blow,) or by popping up into the vertical to stay behind him. However, this is best done if you're in a ship with a superior climb rate, because a smart defender will see you pop into the vertical and counter by going vertical himself, in which case the scissors will continue in the vertical. Then the fight has developed into the "rolling scissors:"

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Well, that's a simplified version of what could happen. Visibility is a serious concern in RL. Also, simply going vertical could prove fatal to the defender, depending on the specific situation, so it's far from being a simple 1 + 1 = 2 logic here.
Only a handful of pilots were/are skilled enough and able to remain cool in a life or death situation to manoeuver "by the book". A standard manoeuver when in combat is called "OMG! I don't want to die." It comes in many variations and is never equally effective. Some of these defending pilots are able to counter the attackers shift in position, others never see it, still others simply do something silly in fear for their life and either get lucky or die. There's one thing that probably all combat pilots that ever lived agree on:"Better lucky than good!"

Demetrious said:

Just a note- both the P-47 and P-51 were superior to the Fw-190 in sustained turns, and I think both of them were better in instantaneous turns as well.

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A bit offtopic, but AFAIK that would be true only above rated altitude of the Fw in question. Generally the Fw was better, tho the differences were never huge. The most troublesome fighters for the Fw, when it came to turning, were Spitfires (in the west).

timshatz said:

Barney, I think you're talking about a snap roll. Definitely a defensive act. Stick back, rudder over, Aircraft should snap over in the direction of the rudder, moving to the side. Moves faster if you go towards the side of the engine "on" torque (and the opposite holds true, or at least should, for engine "off" torque). But it happens so fast that engine speed is usually set through the manuver even if you increase throttle.

I'm not sure how adding the alerions would affect it. I think, never having done one with the alerions, it would make it a bit hairy. Stick back and in the corner, rudder to the side....hmmmmm.

One thing about the snap roll is it is not pretty or fun to do. It is quick and somewhat sloppy. Alerion rolls are much nicer. Can keep 1 g through the roll easily. Look nice too.

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Okay, I understand, a high speed stall of one wing brought on by applying G's to the airframe and then rudder to cause rotation. Pilots were taught to avoid high speed stalls but I suppose they then learned to exploit them. I have read wartime experiences of pilots who claimed to have used all sorts of insane tricks to get out of tight situations so this maneuver may have been common. However, I still think most abrupt maneuvers, to get out of a firing solution, were aileron rolls followed by back pressure. Otherwise, why the interest in roll rate?

I'm not so sure the airplane stalls at all during a flick roll. I think (but am truely not sure) that stalling in the middle of flick roll would probably bring on a tumble and you'd be out of control. On the good side, you'd also be out of your opponents gun site Probably everyone else's too!

As for the roll rate being important, I guess they use that for interest in exploiting an apponents disparity to the aircraft characteristics. As is commonly quoted, 75% of pilots never see the guy that gets them. So the most common (and effective) attack is a suprise "shoot and scoot" attack. I would not be suprised if the guy who gets shot down is concentrating on shooting on someone else and is not looking over his shoulder. Hence, the bad news for him.

But on those odd occasions where you actually have to manuver (probably one in 10 in terms of engagements), knowing the weeknesses of the opponent is a useful bit of info. Roll rate is sometimes confused with turn rate. While some aircraft roll very quickly, they may not turn very well at all. Or, they may turn well at one altitude but not so well at another. All that stuff comes into the equasion when you're stuck in a turning fight.

To my understanding, most experienced pilots avoided turning fights for a couple of reasons. One, if you were concentrating on one guy, somebody else could blow into your fight and clobber you. Two, it became a question of advantages that appear and disappear throughtout the engagement. And that lowers your chances of winning. If you are attacking a guy who doesn't see you, odds favor you that your attack will succeed. Probably very high chance. If a guy sees you and turns into your attack, your odds of success just dropped.

To my mind, if you are noticed by the other guy and you don't have a large advantage, and you have the opportunity to leave, do so. Especially if you were in an airforce that didn't rotate their pilots (Soviet, German, Japanese, ect). They'll be back tomorrow, you can get them then.

LWulf said:

Well, that's a simplified version of what could happen. Visibility is a serious concern in RL. Also, simply going vertical could prove fatal to the defender, depending on the specific situation, so it's far from being a simple 1 + 1 = 2 logic here.
Only a handful of pilots were/are skilled enough and able to remain cool in a life or death situation to manoeuver "by the book". A standard manoeuver when in combat is called "OMG! I don't want to die."

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To be sure. One of the big issues with the rolling scissors is that it is extremely taxing on the situational awareness of both attacker and defender, so in some cases you'd enter the rolling scissors as much in the hopes the enemy pilot will lose sight of you and allow you to disengage (or kill him) rather easily.

Of course, pilot skill being the huge determinant of fights it is, it almost doesn't bear mentioning. A skilled pilot is just liable to win simply because he timed his initial merge properly as he is because he knows the rolling scissors. But you do raise an important consideration about any offensive or defensive maneuver- there's a lot of important factors to consider besides how the maneuver meshes with comparative aircraft performance, and these are often a bigger decider of fights then who's roll rate favors a particular maneuver more.

A bit offtopic, but AFAIK that would be true only above rated altitude of the Fw in question. Generally the Fw was better, tho the differences were never huge. The most troublesome fighters for the Fw, when it came to turning, were Spitfires (in the west).

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Everything I've read indicates that the Fw-190 turned like a freight train on ice. The P-47 was not much nimbler, but wasn't horrid, and the P-51 turned pretty well- a little better then an Me-109 and just a hair worse then a P-40 on the deck (which was an above average turner.)

Now that I reflect though, I don't see why I remembered the Fw-190 as being slower in instantaneous turn response. It had pretty high wing-loading and IIRC the general consensus among the flight models of better simulators gives it good instantaneous turn response. Combine that with a good power-weight ratio, good acceleration, the insane roll rate, and a decent climb rate, and you have a great energy fighter that is a slippery target.

thiimshatz said:

I'm not so sure the airplane stalls at all during a flick roll. I think (but am truely not sure) that stalling in the middle of flick roll would probably bring on a tumble and you'd be out of control.

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A snap roll is a stall- by yanking back on the stick and giving it sharp left or right rudder you're forcing one wing to stall before the other, which effectively makes the plane enter a spin in the horizontal plane. Once you enter a snap roll you are out of control!

And therein lies the danger- a snap roll, being essentially a departure stall- can put you in a spin if you're careless enough, and that can develop into a flat spin.... yeah.

Demetrious said:

Everything I've read indicates that the Fw-190 turned like a freight train on ice. The P-47 was not much nimbler, but wasn't horrid, and the P-51 turned pretty well- a little better then an Me-109 and just a hair worse then a P-40 on the deck (which was an above average turner.)

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I think people confuse turn rate and turn radius a lot. I think of it as being able to make a 180 degree change in direction the fastest. as i understand it, thats not always the tightest turn.

I've also read that the 190 would sink 300-500ft in sudden turn maneuvers or dive pull outs. This would make it a horrible plane to turn with at lower altitudes.

You read those combat reports of P-47s turning on FW190s under 2000ft, and this might have something to do with it.

In a guns attack the attacker's wings need to be in the same plane as the defender's wings. That is why a high rate of roll was useful for a defender. That is why Bob Johnson used his Jug's roll characteristics to evade a Spitfire in a mock dogfight.