WW2 fighter turning performance comparisons

[renrich]

bryce, somewhere in this forum you will find a couple of reports that compare the performance of the P51B with the F4U1 and the F6F3 and also a FW190A4 with the two navy fighters. I believe you might find it interesting.

[bryce]

Thanks renrich, would you be referring to this...

http://www.wwiiaircraftperformance.o...0/ptr-1107.pdf

I have read many posts at this forum that claim these reports show bias against the Axis aircraft?

[renrich]

bryce, you have one of the comparisons but there is another that compares the P51 with the navy planes. They find the P51 unsuitable for carrier operations because of insufficent slow speed controllability among other draw backs. These reports are intriguing to me because, if the reports are accurate they show that first, two navy fighters that supposedly are inferior inherently because they are shipboard fighters, are superior if flown to their strong points to two premier WW2 fighters. If that is true then the designers of those aircraft must have been geniuses. Second, and what is more likely, is that almost any first line fighter of any nation in WW2 if flown by a superior pilot will have at least an even chance against any other first line fighter if he knows his plane's strong points and is able to exploit those strong points against what he knows are his enemy's weaknesses. There was no such thing as an a/c without weaknesses since all a/c are compromises.

[Mike Williams]

Hi guys: Here's a US Navy Evaluation and Comparison Trials of the P-51B and F4U-1
I don't know if the F4U ever used 65" Hg MAP operationally. Anyone know? I do know that the P-51 used higher than the 67" Hg MAP limits of this test on operations in the ETO; i.e. 72" & 80" Hg (+25 lbs) MAP.

[Kukuruznik]

Ok so there is no centralised databank for WW2 aircraft turning circles, and that includes also bombers and other types for whom it is important such as transports. Have you compiled anything of the kind Bryce?

I'd like to ask if there is more then one source of roll rate online?

Its interesting that these two performance indicators are not usually given in aircraft data although apparently considered very important by the pilots.

Cheers

[FLYBOYJ]

Originally Posted by Kukuruznik

Its interesting that these two performance indicators are not usually given in aircraft data although apparently considered very important by the pilots.

Cheers

These are not put in aircraft performance charts because turn rates vary with bank angle and speed, also factor in aircraft loading and weight. Not necessarily finite numbers that would be of interest of pilots during the heat of combat especially when you could manipulate the turn by skidding or slipping.

[Brain32]

Originally Posted by bryce

but I must say I was very interested in this diagram…

http://www.wwiiaircraftperformance.org/wade-turning.jpg

I have heard many people say at this forum that the P-51 is over rated in a dogfight, so I was surprised to see it rated with a very good turning circle.

I was even more surprised to see how poorly rated the FW-190As turning circle was.
I have always thought that the FW-190A turning circle would be more comparable to the P-51, rather than the P-47 and Bf-109G?

That diagram is very interesting, but it has some contradicitons with other AFDU material, even the one you can find on the same site.
For example the Mustang3 is highly rated on this diagram while FW190 turns out to be very poor.
However this is what MustangMkIII tactical trial has to say about it and I quote:

"Turning circle
42.Again there is not much to choose. The Mustang is slightly better...."
That was against BMW801 engined FW190, who knows which one and in what condition. Would you say that above diagram says "not much to choose" and "slightly better"?

[pbfoot]

I would think a major factor in turning would be the condition of the pilot if he was in superb condition he might be able to turn to the aircrafts potential realizing G suits were not in vogue during this period

[drgondog]

Originally Posted by krieghund

One thing which is not usually talked about is Specific Excess Power....
Sustained turn is ok as it is a measure of an aircraft's SEP but one important factor is energy (or speed loss) durning the maximum turn rate.

For example a A6M2 at low level full power at 230 mph pulling a hard break turn for 180 degrees has a turn radius of 1118 feet and ends up with 186 mph remaining.

Now a Spitfire Mk II with the same conditions if pulling the same g's will do the same turn radius....question is what is his remaining airspeed after 180 degrees and how close was he to stalling out?

If the Zero has more SEP he could keep the same radius and use his extra SEP for altitude but ending at the same speed as the Spit II only he is above and has the advantage.

Remember the old addage; "out of airspeed and ideas"

I am writing a computer program to give these answers which of course is how modern jet combat is calculated.

More to come.......

Which is close to the thesis of Energy Manueverability and subsequent generated airframe design performance criteria that Boyd developed at great personal career sacrifice in USAF in the 50s and 60s - leading to the F-16 and F-15s

He`crafted the concepts at USAF Fighter School at Nellis post Korea and demonstrated to everyone's dismay that ALL the multi role fighters we had in ops and on the boards were inferior in fighter to fighter Energy manueverability to the Mig19 and Mig21 - and sure enough proved it in VietNam

[drgondog]

Originally Posted by Mike Williams

Hi guys: Here's a US Navy Evaluation and Comparison Trials of the P-51B and F4U-1
I don't know if the F4U ever used 65" Hg MAP operationally. Anyone know? I do know that the P-51 used higher than the 67" Hg MAP limits of this test on operations in the ETO; i.e. 72" & 80" Hg (+25 lbs) MAP.

Hey Mike - as a cynic I might have suggested a couple of months back that the prime off line instructions to the Navy pilots conducting the tests "Don't come back with a conclusion that the 51 is superior in any way" - which is why the Patuxent River tests are not accompanied by Turn and acceleration comparisons at various speeds and altitudes - lol - but definitely accompanied by statements that the F4U out turned, accelerated and climbed better -

[Kukuruznik]

Originally Posted by FLYBOYJ

These are not put in aircraft performance charts because turn rates vary with bank angle and speed, also factor in aircraft loading and weight. Not necessarily finite numbers that would be of interest of pilots during the heat of combat especially when you could manipulate the turn by skidding or slipping.

Yes, ok, but good pilots knew what their aircraft could take (and they could take in terms of Gs), and in most memoirs the words 'turn' and 'roll' are mentioned very frequently. I'm looking for optimum of course, as any pilot of the period would be also.
The problem with memoirs is that they give descriptions of combats that rarely provide technical data (of course!), and this data is not readily available from other sources I find.
Of course its early days in my research, so I may be able to dig up something eventually. However given all the sites online dedicated to study of WW2 combat aircraft, I am rather surprised of the lack of data on these two aspects of air combat...or even discussion.

Cheers

[FLYBOYJ]

Originally Posted by Kukuruznik

Yes, ok, but good pilots knew what their aircraft could take (and they could take in terms of Gs), and in most memoirs the words 'turn' and 'roll' are mentioned very frequently. I'm looking for optimum of course, as any pilot of the period would be also.
The problem with memoirs is that they give descriptions of combats that rarely provide technical data (of course!), and this data is not readily available from other sources I find.
Of course its early days in my research, so I may be able to dig up something eventually. However given all the sites online dedicated to study of WW2 combat aircraft, I am rather surprised of the lack of data on these two aspects of air combat...or even discussion.

Cheers

For what you're looking for your going to have to ask the respective engineer. For the most part when you're in an aircraft and turning there is one instrument your going to use, and it comes in two different configurations depending of the size of your aircraft...

[Crumpp]

There are a couple of very practical reasons why sustained level turn ability is much more important to today's computer gamer than it is to a fighter designer or pilot in RL.

Facts are all aircraft at the same velocity and angle of bank will make exactly the same turn.

That is a very powerful fact. Sustained turning ability is a function of the fundamental relationship of aircraft performance, power available to power required. However, the most important factor in turn performance is velocity. The slower aircraft will always outturn the faster aircraft.
In BGS terms:

Radius of turn = Velocity in Knots^2 divided by the product of correction factor of 11.26 because we are using Knots and the tangent of the angle of bank.

r = Vk^2 / (11.26* tan AOB)

The portion of the envelope in which any design contemporary fighter has an advantage over another design is very small.

This small portion occurs at the popular term of flying at the edge of the envelope.

My experience comes as a pilot, aircraft owner, and someone formally trained in aerodynamics. I throw a big BS flag on any claims of consistent flight at the edge of the envelope. Pilots certainly may come close to "the edge". Many have to change their shorts when they do brush up against it. Many pilots are dead after thier first real brush with the "edge". Facts are flying at any portion of "the edge" is very detrimental to controlled flight and in the majority of cases downright deadly.

Some quick examples:

1. Flying at the "edge" of the cruise envelope all it takes is a gust of wind to damage or destroy the airframe.

The red line is preceded by a yellow band which is the caution area, which runs from VNO (maximum structural cruise speed) to VNE

Airspeed indicator - Wikipedia, the free encyclopedia

2. Flying at the "edge" of our turn performance envelope, that same gust of wind will induce a stall and chances are it will be an aggravated or uncoordinated stall. Now we are in danger of experiencing a spin.

The difference in altitude required to recover from stalls and spins is significant. Most airplanes recover from a "normal" stall in several hundred feet, assuming the pilot recognizes it and takes prompt corrective action. Variables such as weight, aerodynamic design, power setting, load on the wing (Gs), and center of gravity (CG) have an effect, which can be pronounced. In an incipient spin recovery the pilot's operating handbooks (POH) of many aircraft are not very clear about altitude loss. Based on anecdotal observation and the few POHs that do provide data, plan on 1,000 to 1,500 feet as the bare minimum altitude loss, assuming that the pilot was right there with a textbook recovery. Under the best conditions it probably takes at least three to five times as much altitude to recover from an incipient spin as from a stall.

AOPA Online - ASF Article of the Month - Safety Pilot: Spinning In

If it occurs without sufficient altitude to recover we have lost our life.

No matter what "edge" you choose, there is a very real danger of turning our controlled flight into a fight for survival. That is not even factoring in another airplane with a pilot trying to kill us!

It takes a very skilled and experienced pilot to fly the highest performance and most technologically advanced aircraft of the day anywhere close to the edge. The kind of skill and experience only a small percentage of pilots in any given force are capable of exhibiting.

Given the reality of flight and the fact aircraft performance is not an absolute but rather a percentage range over a mean average, only a handful of WWII designs stand out as having a sustained turn performance that would even be noticeable in the air.

If anyone is interested, I have done the calculations for several WWII fighter design sustained turn performance and could post the results as well as the methodology used.

All the best,

Crumpp

[FLYBOYJ]

Originally Posted by Crumpp

It takes a very skilled and experienced pilot to fly the highest performance and most technologically advanced aircraft of the day anywhere close to the edge. The kind of skill and experience only a small percentage of pilots in any given force are capable of exhibiting.

[drgondog]

Originally Posted by Crumpp

There are a couple of very practical reasons why sustained level turn ability is much more important to today's computer gamer than it is to a fighter designer or pilot in RL.


That is a very powerful fact. Sustained turning ability is a function of the fundamental relationship of aircraft performance, power available to power required. However, the most important factor in turn performance is velocity. The slower aircraft will always outturn the faster aircraft.
In BGS terms:

Radius of turn = Velocity in Knots^2 divided by the product of correction factor of 11.26 because we are using Knots and the tangent of the angle of bank.

r = Vk^2 / (11.26* tan AOB)

The portion of the envelope in which any design contemporary fighter has an advantage over another design is very small.

This small portion occurs at the popular term of flying at the edge of the envelope.

My experience comes as a pilot, aircraft owner, and someone formally trained in aerodynamics. I throw a big BS flag on any claims of consistent flight at the edge of the envelope. Pilots certainly may come close to "the edge". Many have to change their shorts when they do brush up against it. Many pilots are dead after thier first real brush with the "edge". Facts are flying at any portion of "the edge" is very detrimental to controlled flight and in the majority of cases downright deadly.

Some quick examples:

1. Flying at the "edge" of the cruise envelope all it takes is a gust of wind to damage or destroy the airframe.



Airspeed indicator - Wikipedia, the free encyclopedia

2. Flying at the "edge" of our turn performance envelope, that same gust of wind will induce a stall and chances are it will be an aggravated or uncoordinated stall. Now we are in danger of experiencing a spin.



AOPA Online - ASF Article of the Month - Safety Pilot: Spinning In

If it occurs without sufficient altitude to recover we have lost our life.

No matter what "edge" you choose, there is a very real danger of turning our controlled flight into a fight for survival. That is not even factoring in another airplane with a pilot trying to kill us!

It takes a very skilled and experienced pilot to fly the highest performance and most technologically advanced aircraft of the day anywhere close to the edge. The kind of skill and experience only a small percentage of pilots in any given force are capable of exhibiting.

Given the reality of flight and the fact aircraft performance is not an absolute but rather a percentage range over a mean average, only a handful of WWII designs stand out as having a sustained turn performance that would even be noticeable in the air.

If anyone is interested, I have done the calculations for several WWII fighter design sustained turn performance and could post the results as well as the methodology used.

All the best,

Crumpp

Crumpp - With enormous respect to you, I agree everything you said except the flat statement that

Facts are all aircraft at the same velocity and angle of bank will make exactly the same turn.

If you mean by the above statement that all exact model aircraft at same weight and configuration (external stores) - then I agree

For dissimilar aircraft entering that turn I would disagree as I think you would also. The "G" forces will be exactly the same as long as the velocity and angle of bank are the same - but aerodynamics (energy bleed) and wing loading and airfoil properties will immediately enter into the equation

Not all a/c could 'maintain' the same angle of bank and airspeed given reasonably close thrust to weight equivalency. I have in mind an F-105 in a turn with a Jap Zero to illustrate the problem with the concept.. or even a very light F105 in a turn with a heavily loaded one.

For every other comment I am in violent agreement