# Roll rate P47 VS FW190



## pinsog (Oct 30, 2009)

Which had the faster roll rate P47 or FW190? I tend to believe the P47 did, but does anyone know for certain?


----------



## drgondog (Oct 30, 2009)

pinsog said:


> Which had the faster roll rate P47 or FW190? I tend to believe the P47 did, but does anyone know for certain?



The Fw 190 out rolled the 47, the 51, the 109, the Spit at low to medium speeds. IIRC at 250mph it had a rool rate nearly 150 degrees per sec, the 47 was near 95-100, the 51 around 90 and the 109 around 75-80 degrees per sec. 

At high speeds the P-47 and P-51 gained rapidly, still maintaining their roll rates but the Fw 190 dropped away - below the 47 and 51 at around 325Kts.

I will have to dig to recall the charts of roll rate vs airspeed.


----------



## marshall (Oct 30, 2009)

Fw 190

http://www.wwiiaircraftperformance.org/naca868-rollchart.jpg


----------



## renrich (Oct 30, 2009)

The roll chart is certainly useful and demonstrates, at least to me, how misleading certain information can be. In Bob Johnson's book, "Thunderbolt" he said that the Jug could outroll a Spitfire and he used it's rolling advantage in mock dogfights. I had read in Dean, "America's Hundred Thousand," that the P47 was not known for being a good roller. Johnson said that when a Spitfire got on his tail, he would dive and roll. The chart shows that the Spitfire rolls really well until about 280 mph where the P47 begins to outroll it. That explains Johnson's tactics. In a dive, he was probably exceeding 280 mph plenty fast.


----------



## Civettone (Oct 30, 2009)

It depends which version. For instance the P-47N rolled better than the D.

Oh and the Spit ... similar story. Which Spitfire? Which wings? Clipped or not ?

Kris


----------



## DAVIDICUS (Oct 30, 2009)

I believe the P-47 was well known for being a good roller and it is widely reported that the "N" rolled better than the "D". 

_The F4U also rolled well. When rolling in conjunction with powerplant torque, in other words, rolling left, it was among the very fastest rolling fighters of the war. In the inventory of American fighters, only the P-47N rolled faster, and only by 6 degrees/second._

Chance Vought F4U-4 Corsair



_The XP-47N took to the air for the first time on July 22, 1944. Test comparisons were made with a P-47D-30-RE throughout the early portion of the evaluation period. Much to everyone’s surprise, the XP-47N, with its greater wingspan and higher weight actually proved to have better roll performance than the D model. At 250 mph TAS, the N attained a maximum roll rate just over 100 degrees/second. The P-47D-30-RE could manage but 85 degrees/second at the same speed. At higher speeds, the N widened the gap further. In mock combat with a P-47D-25-RE, the new fighter proved to be notably superior in every category of performance. In short, the XP-47 waxed the venerable D model regardless of who was piloting the older fighter. The new wing was part of this newfound dogfighting ability, however, the more powerful C series engine played a role too. The additional horsepower allowed the N to retain its energy better than the older Thunderbolt. Perhaps the greatest performance increase was in maximum speed. Though not as fast as the stunning P-47M, the heavier N was fully 40 mph faster than the P-47D-25-RE and could generate speeds 30 mph greater than its principal rival, the Mustang. Scorching along at 467 mph @ 32,000 ft., the N could not be caught by any fighter in regular service with any air force on earth with the single exception of its M model sibling. This combination of wing and engine had pushed the N model up to the top rank of the superlative prop driven fighters then in existence._

Seversky Aircraft and Republic Aviation



Francis Gabreski also raved about the outstanding roll performance of the P-47. In fact, he said that rolling was a tactic used by P-47 pilots due to it's capabilities. If you do a web search for " P-47" and "roll" you will find more than a dozen accounts in just a few pages.



Relevant to Bob Johnson's claim, there is an RAF Air Fighting Development Unit tactical trial between the P-47C and Spit Mk. IX that concludes:

P-47C v. Spitfire IX --

25. Manoeuvrability – The good aileron control gives the P-47 an excellent rate of roll even at high speeds, and during mock combats it was considered to roll as well as, if not better than the Spitfire at about 30,000 feet. At lower altitudes there is nothing to choose between them.

P-47 Tactical Trials



In other tests by the USAAF Proving Ground Command, it was concluded that:

"The rate of aileron roll is the best found in any type of American fighter."

P-47C Tactical Trials
.
.
.


----------



## renrich (Oct 30, 2009)

Interesting because data from NACA TR868 and Perkins and Hage show both the P40 and P40F to be much superior in rate of roll to the P47C1. Page 255 in Dean, "America's Hundred Thousand," P40 airplanes were particularly good in roll. An early model was shown in one report as having a maximum roll rate of 135 degrees per second at an indicated air speed of 360 mph. Later data show a P40F having a peak rate of 95 degrees per second at about 275 mph IAS. In any case pilots attested to high roll rates. For the P40C "It had an extremely high rate of roll" For the H87A/P40E "The rapid roll rate, the most delightful aspect of the P40" And other comments: "The extremely rapid roll rate-" "Roll are effortless" "Rolling performance was excellent; I think it was as good as any AAF fighter", "Rapid aileron response, by comparison the P51 was locked in cement" and " Roll was great".


----------



## DAVIDICUS (Oct 30, 2009)

Interesting indeed.



PROOF DEPARTMENT
TACTICAL COMBAT SECTION
ARMY AIR FORCES PROVING GROUND COMMAND
EGLIN FIELD, FLORIDA

FINAL REPORT ON TACTICAL SUITABILITY OF THE P-47C-1 TYPE AIRCRAFT 

18 December 1942
...
6. DISCUSSION: 
...
(3) Maneuverability -- The P-47C-1 was flown in mock combat against the P-38F, P-39D1, P-40F, and the P-51. 
(a) It had superior rate of aileron roll at all speeds, and especially at high speed to all American fighter contemporary types, none could follow it in a fast reverse turn. 
...
(e) In close fighting the P-47C-1, due to its faster aileron roll, can quickly reverse turn and break off the combat almost at will. 

P-47C Tactical Trials
.
.
.


----------



## drgondog (Oct 30, 2009)

DAVIDICUS said:


> Interesting indeed.
> 
> 
> 
> ...



D - you do know the P-51 in those trials was the P-51A with the Allison which was slower in roll than the 51B?


----------



## renrich (Oct 30, 2009)

Well, it all goes to show that the information we see bandied about can be inaccurate. Perhaps some of the discrepancies can be traced to the individual AC tested or perhaps that performance varied so much at different altitudes or I don't know. I saw the report of the comparison of the A6M versus various US AC and a number of the Army AC had mechanical problems which prevented from completing all the comparisons. The Zero kept chugging along though. Reminds me a little of comparing some Japanese cars with some US cars, especially a few years ago.


----------



## Kurfürst (Oct 31, 2009)

renrich said:


> The roll chart is certainly useful and demonstrates, at least to me, how misleading certain information can be. In Bob Johnson's book, "Thunderbolt" he said that the Jug could outroll a Spitfire and he used it's rolling advantage in mock dogfights. I had read in Dean, "America's Hundred Thousand," that the P47 was not known for being a good roller. Johnson said that when a Spitfire got on his tail, he would dive and roll. The chart shows that the Spitfire rolls really well until about 280 mph where the P47 begins to outroll it. That explains Johnson's tactics. In a dive, he was probably exceeding 280 mph plenty fast.



Keep in mind the chart shows peak roll rates - roll acceleration is not shown, ie. the ability of the aircraft to roll quickly. This can be significantly different, as some aircraft were quick and brisk in their rolls, others were sluggish and lazy, and though eventually speeded up, this has of less practical use in combat.

The practical rolling manouverability in combat is better gauged by time to bank figures, which would take into account the initial acceleration as well.


----------



## renrich (Oct 31, 2009)

Kurfurst, thanks for your comment. A question I have, actually two, is: a plane must bank before it turns so I can see how the initial part of the roll is important. Quicker is better. The P38 had an initial resistance to roll so it did not turn very fast. Johnson, in his book, though knew he could not outturn a Spitfire so he rolled first one way and then the other while diving. What i gather from that is that it is better for the attacker's wings to be in the same plane as the plane being attacked. I don't really understand why that is an advantage, especially against an AC with all guns located near the center of the longitudinal axis. Another question is from the rolling point of view. Dean says that a four second 360 degree roll was good for a WW2 fighter. Obviously that is about 90 degrees per second. To me, the difference between say a 90 degree per second roll rate and an 80 degree per second roll rate would not be of great moment. The L39 has a roll rate of around 360 degrees per second. I once did a couple of aileron rolls at 250 knots IAS in one and that roll rate seems almost instantaneous. Watching film of a WW2 fighter in a 4 second 360 degree roll seems really slow. This post is reall y clumsy but I would enjoy any comments.


----------



## Altea (Oct 31, 2009)

renrich said:


> Kurfurst, thanks for your comment. A question I have, actually two, is: a plane must bank before it turns so I can see how the initial part of the roll is important. Quicker is better. The P38 had an initial resistance to roll so it did not turn very fast. Johnson, in his book, though knew he could not outturn a Spitfire so he rolled first one way and then the other while diving. What i gather from that is that it is better for the attacker's wings to be in the same plane as the plane being attacked. I don't really understand why that is an advantage, especially against an AC with all guns located near the center of the longitudinal axis. Another question is from the rolling point of view. Dean says that a four second 360 degree roll was good for a WW2 fighter. Obviously that is about 90 degrees per second. To me, the difference between say a 90 degree per second roll rate and an 80 degree per second roll rate would not be of great moment. The L39 has a roll rate of around 360 degrees per second. I once did a couple of aileron rolls at 250 knots IAS in one and that roll rate seems almost instantaneous. Watching film of a WW2 fighter in a 4 second 360 degree roll seems really slow. This post is reall y clumsy but I would enjoy any comments.




First and foremost, the L-39 roll rate being really *excellent*, is not *that excellent* for sure!!!
I can call my friend Sergei Burdin an instructor with 6500-7000 hours flight on that type to have more accurante datas, if you want so.

It shows how difficult it is to estimate roll on nimble planes

From pilots notes you roll at 400 km/h on that type. Even faster. Your aspect ratio is only 4.75 for a wingspan of 9.46, and see your aileron aeras. Maybe the wing tank plays is rule for pressure/lift conservation on wing tips. To resume, it'a short, square wing with big ailerons on it, and some device fighting against marginal pressure losses.. Nothing surprising, only logic for your fast barrels.
P-47/F4U/P-38/F6F have a lot of planes parts with some weight far away from the GC. It's not good for inertia moments. Moreover if you compare the rolling wing to a turning windmill blade, it takes a cubic low for speed for a linear lengh increase. Applying that model, the 10% smaller wing should turn 33,1% faster using the same energy for that.

BTW the best warbird "roller" from european collectors seems to be the Yak-11 (and so probably the 3). But it performs it at a much lower speed (250-300 km/h). You can easily see it from a flight demonstration at the Ferté Alais or Meulun-Villaroche with a good pilot on commands.

Moroever; i dont think that "your" L-39 has a better roll rate than "my" Yak-55* ! 

*An old souvenir (1994...).

Regards


----------



## renrich (Oct 31, 2009)

The spec sheet I have on the L39 shows a RR of 300 degrees per second at 250 KIAS. Believe me that when I threw the stick hard against my leg it rolled plenty fast. Hard to tell without a stop watch but it seemed like almost gorrilla one.


----------



## Civettone (Oct 31, 2009)

Kurfürst said:


> Keep in mind the chart shows peak roll rates - roll acceleration is not shown, ie. the ability of the aircraft to roll quickly. This can be significantly different, as some aircraft were quick and brisk in their rolls, others were sluggish and lazy, and though eventually speeded up, this has of less practical use in combat.
> 
> The practical rolling manouverability in combat is better gauged by time to bank figures, which would take into account the initial acceleration as well.


Thankfully someone pointed this out !!!
The same goes for the climb and turn rate. All you see charts or information about is about constant climbing/turning/rolling but not about the instantaneous climb/roll rate.

This acceleration is sooo important but never gets much attention. I also believe that is what the real strength of the Bf 109 and Fw 190 was...

Kris


----------



## Altea (Oct 31, 2009)

renrich said:


> The spec sheet I have on the L39 shows a RR of 300 degrees per second at 250 KIAS. Believe me that when I threw the stick hard against my leg it rolled plenty fast. Hard to tell without a stop watch but it seemed like almost gorrilla one.




Ok, ok...So share your full spec sheet with us! It' from a great kind of interest as a "study subject" for short winged planes as I-16, Yaks, Laggs; 109s...


There is moreover, not such an information in russian pilot's notes booklet about that, and you're the L-39 specialist here, not me.

Regards


----------



## billswagger (Jan 6, 2010)

Its pretty much a no brainer. The FW190 was much better in roll at typical combat speeds and really only clipped wing spitfires came close to matching the rate of roll.

I think the jug has its reputation for good roll performance because it was designed to fly at higher speeds where the ailerons were adjusted to still be able to respond even under moderate compressibility. Also the control feel in such rolls was said be comfortable where rolls in the P-51, and P-38 were said to be heavier above 300IAS. (save: until hydraulic s on the 38 were used)

It is its ability to roll at high speeds where it was more impressive than a spitfire, and where the FW would lose roll performance. So 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. Planes diving to get away might roll and maneuver to lose a tailing plane, so perhaps in this area of the envelope the two planes were more close in roll rate. 

bill


----------



## barney (Jan 6, 2010)

Rolling quickly just keeps you in the enemy's gun sight. Rolling is only useful in assuming the correct attitude for turning. So, rolling and turning are components of the same maneuver. In other words, if you have an aircraft that is good roller but a lousy turner, how fast the aircraft can roll doesn't mean much if all your enemy has to do is touch his rudder to shoot you down. So, I suggest, to be meaningful, the two in combination should be considered.


----------



## timshatz (Jan 6, 2010)

barney said:


> Rolling quickly just keeps you in the enemy's gun sight. Rolling is only useful in assuming the correct attitude for turning. So, rolling and turning are components of the same maneuver. In other words, if you have an aircraft that is good roller but a lousy turner, how fast the aircraft can roll doesn't mean much if all your enemy has to do is touch his rudder to shoot you down. So, I suggest, to be meaningful, the two in combination should be considered.



But there are also a bunch of different rolls. Snap roll, barrell roll, ect. 

I think you're talking about a slow roll. But something like a snap roll can be useful to get you out of the gunsight quickly. Kind of a horizontal displacement to one direction or the other.


----------



## barney (Jan 6, 2010)

timshatz said:


> But there are also a bunch of different rolls. Snap roll, barrell roll, ect.
> 
> I think you're talking about a slow roll. But something like a snap roll can be useful to get you out of the gunsight quickly. Kind of a horizontal displacement to one direction or the other.



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.


----------



## billswagger (Jan 6, 2010)

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.




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.


----------



## MikeGazdik (Jan 7, 2010)

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.


----------



## LWulf (Jan 7, 2010)

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.


----------



## Demetrious (Jan 7, 2010)

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.



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.



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.


----------



## LWulf (Jan 7, 2010)

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.
> 
> 
> 
> ...



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.


----------



## timshatz (Jan 7, 2010)

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.



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.


----------



## Demetrious (Jan 7, 2010)

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.



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.


----------



## timshatz (Jan 7, 2010)

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.


----------



## davebender (Jan 7, 2010)

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.


----------



## LWulf (Jan 7, 2010)

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:"



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.



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).


----------



## barney (Jan 7, 2010)

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.



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?


----------



## timshatz (Jan 7, 2010)

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.


----------



## Demetrious (Jan 7, 2010)

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."



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).



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.



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.


----------



## billswagger (Jan 7, 2010)

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.)



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.


----------



## renrich (Jan 7, 2010)

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.


----------

