Turn rate hierarchy correlation from actual flight tests

[Karnak]

Gaston,

"Peculiarities" can't violate the rules of physics.

Also, WWII fighters, none of them, produced enough thrust for an Fw190 to overcome the wingloading deficit to out turn a Spitfire Mk V.  If that were the case, the La-7, Spitfire Mk XIV, Ki-84 and N1K2-J would assuredly out turn the A6M5.

[Angus]

   Quote: "More thrust at the same weight will give you a better sustained turn rate. How's that"

   
     -Yes it does make more sense that way, but maybe the peculiarities of the Merlin P-51 airframe with flaps down require the lowering of the throttle. One of the stated advantages of the FW-190A's "brainbox" throttle is that it allowed downthrottling prior to the turn and then throttling up during the turn.

      In the Merlin Mustang's case, it does appear very clearly in the above combat that the lower airspeed increased the turn rate, probably at or below 200 MPH given the number of consecutive turns on the deck (while being gained on!),  and especially decreased the turn radius, to a far higher performance than higher speeds would have allowed.

     Yet at the same time, this 1990 test by several seasoned test pilots revealed a peak turn rate "very close" to the maximum level speed, which I read as above 300 MPH, maybe even as high as 350 MPH. I believe both are correct... Depending on flap position the turn behaviour of the Merlin P-51 is not really a linear rise followed by a linear drop...

     http://bbs.hitechcreations.com/smf/index.php/topic,261798.0.html

    As another example of Merlin P-51 peculiarities, the P-51 clearly accelerates or sustains speed better in level turns than earlier '44 Me-109Gs (not so much the late '44 one in the combat linked above!), yet cannot match their climb rates...

   In any case, it is obvious the lowering of throttle, and prop pitch change with popped flaps, during low speed turns, was a VERY common tactic on the Merlin P-51, and was widely known among US WWII pilots...

   Gaston

     

Drop your power and you will stall. Dead simple. WW2 aircraft did not have the enormous thrust in such an abundance.
Full power will give you the best sustained turn. You may be able to chop the throttle and get a nastyly tight turn...untill you stall out. In that scenario you would be fighting a blackout anyway.....and a better maneuver would be a chandelle.
Anyway, speculate on "POWER LOADING" instead of just wing-loading and HP

[Widewing]

     Yet at the same time, this 1990 test by several seasoned test pilots revealed a peak turn rate "very close" to the maximum level speed, which I read as above 300 MPH, maybe even as high as 350 MPH. I believe both are correct... Depending on flap position the turn behaviour of the Merlin P-51 is not really a linear rise followed by a linear drop...

     http://bbs.hitechcreations.com/smf/index.php/topic,261798.0.html

    As another example of Merlin P-51 peculiarities, the P-51 clearly accelerates or sustains speed better in level turns than earlier '44 Me-109Gs (not so much the late '44 one in the combat linked above!), yet cannot match their climb rates...

   In any case, it is obvious the lowering of throttle, and prop pitch change with popped flaps, during low speed turns, was a VERY common tactic on the Merlin P-51, and was widely known among US WWII pilots...

   Gaston

     

Pulling off throttle entering a turn is always a very bad idea. Want to kill E? Go vertical; a high yo-yo is a far better maneuver than pulling off power. Your speed is reduced, but your potential energy is very high... An ideal position to be in for most engagements when dealing with a slower enemy.

Gaston, just because some WWII pilot did something and survived, that doesn't make it a smart thing to do. There are times when pulling off power is necessary, but to reduce speed to get inside the turn of an enemy is usually not necessary or smart. When you quote a pilot who did this, did it occur to you how many didn't get home?


My regards,

Widewing

[Gaston]

 
   Quote Widewing:"Gaston, just because some WWII pilot did something and survived, that doesn't make it a smart thing to do. There are times when pulling off power is necessary, but to reduce speed to get inside the turn of an enemy is usually not necessary or smart. When you quote a pilot who did this, did it occur to you how many didn't get home?"


   -There are numerous instances of pulling off power to keep overunning a slower opponent (one P-47 even firing guns for that purpose!), especially with the generally faster relative speed of US fighters at high altitudes. But we can all agree that in the example that I quoted, that is, for a TAILING Me-109G, things are here of a completely different nature than downthrottling to prevent a simple overunning...

    This specific combination of actions, downthrottling, popping flaps, changing prop pitch, is one I have encountered a dozen times or more in instances where the P-51 is caught in a low-speed horizontal turn fight, usually on the deck. It is always mentionned in a matter-of-fact way that suggest that whoever is reading it is expected to know what it is about (Not: "I had this sudden idea", or "I tried this unusual action"), which suggests this is a widely accepted procedure. The results are usually large gains on the Me-109G and slower gains on some FW-190As, including those that "snap" their wings a lot, indicating perhaps inexperience on the FW-190 pilot's part. It is not very common, but very characteristic in the situations it is employed: It must have been taught at some level or other, as it is too complicated to have been conjured-up on the spot.

    Downthrottling is also described by a FW-190A Western ace PRIOR to the merge, and is also combined with deploying the flaps. Note that this procedure, as it applies to turning, I have never encountered in 600+ P-47D combat reports, which I consider highly significant. It did not suit the P-47D...

    I can't hunt down and link all the instances I have read about it, but it is common enough, and exclusive enough to the P-51, as to be a sort of "proprietary" tactic that only the FW-190A seems to have a counterpart for... Note also that engine peak torque is always at a lower rpm than peak power, so that could explain the advantage gained. As with the FW-190A's turning advantage, I think in this case I would go with pilots accounts yet again...

   
     Quote, Angus: "Drop your power and you will stall. Dead simple. WW2 aircraft did not have the enormous thrust in such an abundance."

    
    -They did at low speed, and probably more than many fighter jets up to a surprisingly advanced generation...

    Without steam catapults, fighter jet operations from aircraft carriers would be non-existent up to a much later period in history, if at all, because the area of thrust from the jet is so much smaller, and they cannot regain speed as rapidly from low speed, because they need a correspondingly higher speed of air inflow at the front of the intake to generate all this power at the rear.

    There was an interesting acceleration comparison once between a 800 hp(?) Formula 1 race car (0-60 MPH in 1.8/2 sec?) and a 30-40 000(?) hp F-18 fighter jet, both starting from a standstill and accelerating as fast as they could. It wasn't even a close call: The Formula 1 beat the crap out of the F-18 all the way to 200 MPH, because the available purchase area, for all that power to take hold of, was so much better on the car...

    Now take another similar comparison, A 1990s Corvette ZR-1 and a P-51D Mustang: OK, the Corvette takes 4.2 sec or so  to reach 60 MPH, a far cry from the Formula 1, but this time the Mustang had only about four times as many horses, not 40 times! The result? Again, not a close call at all: The Mustang absolutely creamed the Corvette ZR-1 right from the brake release...

   The absence of catapults on WWII carriers alone tells you a lot about how different the rules are, at low speeds, for propeller aircrafts versus jets...

    Gaston

[Widewing]

 
   Quote Widewing:"Gaston, just because some WWII pilot did something and survived, that doesn't make it a smart thing to do. There are times when pulling off power is necessary, but to reduce speed to get inside the turn of an enemy is usually not necessary or smart. When you quote a pilot who did this, did it occur to you how many didn't get home?"


   -There are numerous instances of pulling off power to keep overunning a slower opponent (one P-47 even firing guns for that purpose!), especially with the generally faster relative speed of US fighters at high altitudes. But we can all agree that in the example that I quoted, that is, for a TAILING Me-109G, things are here of a completely different nature than downthrottling to prevent a simple overunning...

    This specific combination of actions, downthrottling, popping flaps, changing prop pitch, is one I have encountered a dozen times or more in instances where the P-51 is caught in a low-speed horizontal turn fight, usually on the deck. It is always mentionned in a matter-of-fact way that suggest that whoever is reading it is expected to know what it is about (Not: "I had this sudden idea", or "I tried this unusual action"), which suggests this is a widely accepted procedure. The results are usually large gains on the Me-109G and slower gains on some FW-190As, including those that "snap" their wings a lot, indicating perhaps inexperience on the FW-190 pilot's part. It is not very common, but very characteristic in the situations it is employed: It must have been taught at some level or other, as it is too complicated to have been conjured-up on the spot.

    Downthrottling is also described by a FW-190A Western ace PRIOR to the merge, and is also combined with deploying the flaps. Note that this procedure, as it applies to turning, I have never encountered in 600+ P-47D combat reports, which I consider highly significant. It did not suit the P-47D...

    I can't hunt down and link all the instances I have read about it, but it is common enough, and exclusive enough to the P-51, as to be a sort of "proprietary" tactic that only the FW-190A seems to have a counterpart for... Note also that engine peak torque is always at a lower rpm than peak power, so that could explain the advantage gained. As with the FW-190A's turning advantage, I think in this case I would go with pilots accounts yet again...

   
     Quote, Angus: "Drop your power and you will stall. Dead simple. WW2 aircraft did not have the enormous thrust in such an abundance."

    
    -They did at low speed, and probably more than many fighter jets up to a surprisingly advanced generation...

    Without steam catapults, fighter jet operations from aircraft carriers would be non-existent up to a much later period in history, if at all, because the area of thrust from the jet is so much smaller, and they cannot regain speed as rapidly from low speed, because they need a correspondingly higher speed of air inflow at the front of the intake to generate all this power at the rear.

    There was an interesting acceleration comparison once between a 800 hp(?) Formula 1 race car (0-60 MPH in 1.8/2 sec?) and a 30-40 000(?) hp F-18 fighter jet, both starting from a standstill and accelerating as fast as they could. It wasn't even a close call: The Formula 1 beat the crap out of the F-18 all the way to 200 MPH, because the available purchase area, for all that power to take hold of, was so much better on the car...

    Now take another similar comparison, A 1990s Corvette ZR-1 and a P-51D Mustang: OK, the Corvette takes 4.2 sec or so  to reach 60 MPH, a far cry from the Formula 1, but this time the Mustang had only about four times as many horses, not 40 times! The result? Again, not a close call at all: The Mustang absolutely creamed the Corvette ZR-1 right from the brake release...

   The absence of catapults on WWII carriers alone tells you a lot about how different the rules are, at low speeds, for propeller aircrafts versus jets...

    Gaston

A couple of points..

Throttling back will not significantly reduce speed by itself. Ideally, the maneuver is to go up, roll and drop back in. The fact was and is that most WWII pilots had very little actual combat. Many in the 8th AF never fired their guns at an enemy fighter. I would expect these guys to do dumb things.

Re: Jet engines... Did you ever hear of "static thrust"? Jet engines are rated in pounds of static thrust, meaning that the engine is securely mounted to a test stand and not moving. The reason an F1 car accelerates faster than the F-18 is that the jet is at idle when the race begins. It takes time to spool up the engines. If the F-18 began with the engines powered up and the burners lit, it would be far more impressive. Piston aircraft engines get to max RPM within a couple of seconds. My S-2F would easily beat an F-4J in a drag race from idle, but if the Phantom started with the burners lit, it simply disappeared.

And finally, by mid war, all US carriers had catapults and they were used more often than not. Especially when the flight deck was full. These were hydraulic cats.


My regards,

Widewing

[guncrasher]

man reading this thread and having to memorize all the different turn rolls (degrees or whatever) its pretty interesting.  

planes came out of the factory pretty much the same way some may have some minor improvements in the field. also, for some reason, some planes were actually better than the one built before or after it. that applies to pretty much any ww2 plane, what made a plane better was the pilot himself.  the best pilot could use a lesser plane to shoot down a crappy pilot in a superior plane, it was proven many times.  Of course the better pilots ended up dying anyway basically because nobody can win all the time.  

but what u guys fail to take into account when you quote all this cool books when trying to make this game as realistic as possible is that we actually dont use the same plane per say (ok forgive me for misquote, grammar or spelling).  some people fly with stall enabled, some dont, some use trackir, most dont, some have better joystick with twist rudders, others dont, some know how to change settings on joystick to make it turn easier, most dont.  shoot, i bet some dont even have joysticks.  there are more variables in this game than just pilot skill.

then again not trying to put anybody down, but sometimes I hear somebody say "my plane should have outturned yours and my skill is better than yours"  that is actually true but the other guy's "extras" could've been better and made the difference.  and when you guys talk about planes in ah, you seem to forget to take into account all the little "extra toys"  that people get in this game which are not on any of the books you guys read about.



semp

[bozon]

     This specific combination of actions, downthrottling, popping flaps, changing prop pitch, is one I have encountered a dozen times or more in instances where the P-51 is caught in a low-speed horizontal turn fight, usually on the deck. It is always mentionned in a matter-of-fact way that suggest that whoever is reading it is expected to know what it is about (Not: "I had this sudden idea", or "I tried this unusual action"), which suggests this is a widely accepted procedure. The results are usually large gains on the Me-109G and slower gains on some FW-190As, including those that "snap" their wings a lot, indicating perhaps inexperience on the FW-190 pilot's part. It is not very common, but very characteristic in the situations it is employed: It must have been taught at some level or other, as it is too complicated to have been conjured-up on the spot.

Reducing throttle and poping flaps is done to reduce turn radius, not to increase turn rate. For maximizing turn rate you want the plane close to its corner speed and keep it there. The combination of increasing drag (flaps) and reducing thrust (throttle back) will prevent them from maintaining this speed.

On the other hand, to fly slow and in a small circle, flaps help in increasing the maximum lift, which helps when the speed falls and you reach the maximum normal angle of attack. Throttling back is then required in order to fight the torque - as the plane slows down, the full throttle torque remains high but the effectiveness of the controls drops. At some point, the controls will not be able to over come the torque primary and secondary effects, even if the pilot is standing on the rudder pedal and trying to roll into the turn. P-38s used to do a tight right handed climbing turn, because 109/190s torque at low speed would flip them over to the left and prevent them from following.

Using flaps in combat was forbidden (by the squadron/group leaders) in some P-51 squadrons. It was considered a bad thing to intentionally get into a situation where they gain you anything. I remember at least one report from an RAF P-51 pilot that was in a long turning circles with a 109 at 0 alt and used the flaps against the official orders. He won the fight, but those that didn't don't come back to tell about it.

[Angus]

Marseille used this choppy trick to get a bead on the enemy. It called on two things though. Firstly, he had to be a good shot and a good stick, for the window of time was very short. He was a good stick and a good shot.
Secondly, he needed his mates to cover him. Which they did, and he got the kills.
Anyway, EF Typhoon vs Bugatti 
(btw, a commonjet engine will use 8 seconds to rev up)
http://www.youtube.com/watch?v=7NZ9X9A2efA
Enjoy.

[hitech]

Note also that engine peak torque is always at a lower rpm than peak power, so that could explain the advantage gained.

Would you please study some basic physics so you will start to understand how stupid this statement you made is.

Power = RPM * Torque.

Lower RPM = less power = less thrust = less turn rate.


HiTech

[WMLute]

Does Gaston even fly AcesHigh.

[Widewing]

Does Gaston even fly AcesHigh.

If he did, he would die...Immediately.



My regards,

Widewing

[Gaston]

  Quote Hitech: "Quote
Note also that engine peak torque is always at a lower rpm than peak power, so that could explain the advantage gained.

Would you please study some basic physics so you will start to understand how stupid this statement you made is."



  -Quote: From "Torque and Power": "Why does power continue to increase after torque decreases?

Remember that the power is essentially the product of the RPM and the torque.  At first, decrease in torque is small and is not enough to offset the increasing RPM, so the overall product still increases. Eventually the decrease in torque becomes large enough that it outweighs the increase in RPM and we see the power start to drop.  Because of this, the power peak will always be after the torque peak."


   -Quote from one of MANY sites if you google: "Torque vs Horsepower"...

  Of course a P-51 flying slower will be doing so with with LESS power than one one flying faster... The issue here is the pilot apparently WANTS less overall power because the extra power pulls him into a wider turn he doesn't want...

  Also at low speeds, it may be useful to have a reserve of power to call on if the aircraft starts to "warn" and you don't want to relax the turn even if it does...

  The lower rpm torque peak does not mean there is more acceleration offered than at higher rpm power settings, there isn't, but it does mean there is not PROPORTIONATELY less acceleration available at a lower power setting and lower speed. In other words, a modest drop in speed and power MAY, in some aircraft types, make a big difference to the aircraft's aerodynamic response to a turn, and thus the tightness of a turning radius, but not as big a difference to the ability of the aircraft's engine to sustain speed in this turn, even if the overall power does drop.

  Clear enough?

  Quote Widewing: "Re: Jet engines... Did you ever hear of "static thrust"? Jet engines are rated in pounds of static thrust, meaning that the engine is securely mounted to a test stand and not moving. The reason an F1 car accelerates faster than the F-18 is that the jet is at idle when the race begins. It takes time to spool up the engines. If the F-18 began with the engines powered up and the burners lit, it would be far more impressive."

   -Of couse the F-18 had its engines spooled-up prior to brake release, or it wouldn't have been a contest at all... I saw the tape.

   Same with the Merlin Mustang: If it had been idling, it would have had no chance vs the ZR-1...


    Quote Angus: "Marseille used this choppy trick to get a bead on the enemy. It called on two things though. Firstly, he had to be a good shot and a good stick, for the window of time was very short. He was a good stick and a good shot."

     -In the linked combat report, the Me-109G was gaining, on the deck, on the P-51D's TAIL, which means this wasn't just an issue of quickly chopping the throttle for a short time: The account is very clear: The Mustang gained gradually over what still would have taken several complete 360° turns to reverse the Me-109G's tailing position, and in fact the US cavalry arrived and interrupted the Me-109G's turn, since the Geman was forced to make a run for it, well before the P-51D had the considerable needed time to reverse the Me-109G's tail position, at least in what could have been called a fair 1 on 1 contest prior to the interruption...

    I'll have a look at that EF vs Bugatti tape: Thanks Angus!

    Quote: Widewing: "The fact was and is that most WWII pilots had very little actual combat. Many in the 8th AF never fired their guns at an enemy fighter. I would expect these guys to do dumb things."

    -Since pilots of the times don't know what went down, why don't you guys find me a Luftwaffe pilot stupid enough to say the Me-109G-6 out-turns the FW-190A?

      Oh, Rall said he could do it, with an Me-109F(!), and he starts by saying "They told us the FW-190A out-turns our Me-109, however I could do it..." So that's not exactly a supporting statement, and not for the "Gustav" by a long shot: Rall in fact complained about the G model being a bit too degraded in handling compared to the F...

      The Rechlin La-5FN test, in late 1944, does say a MW-50 equipped Me-109G out-turns a FW-190A, speed unspecified. See my ranking above, based on the G-14's MW-50 use... And, finally, let's be fair and discount altitudes above 21 000 ft... So that Me-109G-14AS vs FW-190A-9 test at 27 000 ft. doesn't count either...

      Since wartime pilots do indeed say and do dumb things, it shouldn't be too hard to find one pilot dumb enough to say he out-turned the FW-190A in a non-MW-50 Me-109G, and this in sustained turns below 250 MPH...

      Gaston

    P.S. I don't quite know what to make of my ignorance being now lumped-in with the ignorance of WWII fighter pilots...

      G.


    

    
  
    


  

  

  

  

  

[WMLute]

By using the (quote) and (/quote) you are able to insert multiple quotes from multiple posts.
use [ ] not (  )

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(ain't nobody here gonna hold their breath waiting for THAT to happen though...)

[bozon]

  -Quote from one of MANY sites if you google: "Torque vs Horsepower"...

  Of course a P-51 flying slower will be doing so with with LESS power than one one flying faster... The issue here is the pilot apparently WANTS less overall power because the extra power pulls him into a wider turn he doesn't want...

The quote clearly is referring to turn radius not turn rate. In that case the pilot want to keep his speed lower.

Many people, including pilots mix and confuse turning radius and turn rate into the general tern of "out turning". From the pilot's point of view, he pulled on the stick and the enemy plane advanced in his front window from top down to the gun sight and into a lead firing position. If it was pure turn rate, or the geometry of two planes turning on different circles is hard to judge in the heat of things. On top of that, a long sustained turning circles fight will almost never happen at the best turning speeds of either plane.

The result of such a fight will depend on the pilots ability to optimize the speed for a combination of turn rate and turn radius that will win the fight. No point in turning faster if the enemy is inside your circle - you will never get guns on him, unless you "cheat" and displace the circles. If he needs to accelerate to increase his rate of turn, it means that for a few moments he will loose both in angles and in radius as he unloads and let the plane accelerate. I am not sure many pilots nerves will hold long enough to gain from such a gamble.

[thorsim]

none of this will translate to AH anyway other incorrect modeling factors will prevent the proper envelopes from ever showing themselves in the game. 

GL gaston, but there is no interest in this sort of argument in here. 

the game is balanced the way they want it to be balanced.

+S+

t