Which is the better fighter, P-40F or Typhoon?

[Schweik]

There are various roll rates shown for the P-40 as well

Obviously different factors affect it, weight carried, weight distribution, altitude, stick force etc. The numbers read different for various planes if they use various levels of stick force in particular. There is also roll acceleration and the lag somebody mentioned vis a vis the P-38. How quickly can you stop rolling in one direction and begin rolling in the other. I remember all this came up when we were discussing the Hurricane once, some guy kept insisting that the Hurricane had a great roll rate.

Ultimately however these are usually kind of one-offs, like the P-38. Aircraft that appeared to roll well on these charts in fact rolled well in real life.

I admit I really don't get the nuances between the chart Ivan posted and the posts Grayman made. Which interpretation is correct?

 

[Schweik]

Well, your conclusions do come across as being very definite, with little room for doubt; though it may just be your style that gives that impression, I suppose. As for the Statistical Digest, I have tried to find more data, but I haven't found anything that can explain why there are differences between it and MAW IV or unit records; but it does underline how uncertain and confusing WWII data can be.

I try to be specific - for the days I've indicated, the conclusions are solid - within the limits of the data currently available.

For the rest, you can apply Ockham's razor and also observe trends over time.

If you looked at the data in the 1960's or 1970's, the P-40 was a dog. Every book said it was "unmaneuverable and slow, but rugged and available". It was only good as a fighter-bomber. Allied pilots overclaimed so all their victories were probably imaginary. The Luftwaffe were Gods. Blonde Knights of Germany. It was a mystery how they lost the war.

Over time, Luftwaffe looks a bit less stellar. The P-40 looks better and better - based on the data. Turns out that P-40s did shoot down zeroes after all. P-40s did in fact shoot down Bf 109s and more than once. Turns out several experten lost their lives to P-40 pilots. Turns out the Bf 109 did have a few flaws. So did the Fw 190.

You seem to want to imply that everything we know may be wrong. I think that is overstating the uncertainty - I don't know that much about Shores sources for Axis losses, it would be nice if they were published online. I have some idea where he gets the German records but less so about the Italian. However I don't feel there is a lot of doubt about Allied losses for reasons I have already stated at least 5 times now.

It is possible that everything we know right now is wrong. That would depend on how much of the data, in terms of claims vs. losses on both sides, is actually hidden, gone or currently unavailable. Most of the Anglo-American records survived the war. It is true that something like 90% of the Luftwaffe records were lost. But fortunately for researchers they kept a lot of records. So even that 10% tells us quite a bit. We have some gaps in the unit histories for North Africa and Italy, but for the most part it is complete. More to the point, I don't know of any reason to assume that their losses as we currently know them are overstated.

But if it turns out that we actually only know 10% of the pertinent data and 90% is still out there waiting to be found - it is possible the picture could reverse itself again. They might find another 500 Allied fighters shot down. Maybe there is another Marseille we never even heard of somehow and his photo, knights cross and flight log book will be found in a shoe box in Tunisia tomorrow.

Possible but I think at this point, unlikely.

I think we could still see new data that changes our overall perception - I would still expect it to, but incrementally - not by 200 or 300 planes shot down.

However if you have any data showing that please post it by all means!

S

 

[DerAdlerIstGelandet]

No your conclusions are not solid in regards to which aircraft is better. Why? Because as just about everyone pointed out to you, they only paint a part of the picture. There are far to many variables.

 

[Schweik]

If you mean P-40 vs Typhoon, I never said definitively which aircraft is better - I agree there isn't enough data for that. I said this already but at the risk of boring everyone by repetition, Stig1207 isn't referring to the Typhoon here. He and I debated in another thread about the Bf 109 vs. the P-40 which is a much more direct and measurable comparison since they fought each other. (There too I wouldn't say one was better than the other, but that alone is a radical notion since the Bf109 is supposed to be infinitely better according to some.)

To be honest, I am not sure the P-40 and the Typhoon are truly comparable, I thought attempting to compare them would reveal interesting data and it certainly has. The Typhoon seems very flawed to me but the P-40 also had flaws.

I remain unconvinced the Typhoon was maneuverable though I'm ready to learn more. On the other hand it was considerably faster than I had realized. Speed does matter. The maintenance / structural issues may have been less than I thought or maybe they were just as bad, the evidence seems contradictory. Armament was certainly excellent.

Typhoon and P-40F did have a surprisingly similar combat history - both were mostly used for fighter bomber missions albeit for different reasons, both had roughly the same number of planes flying true fighter missions vs. CAS or whatever especially around mid 1943. Both had a similar number of aircraft in action.

But it is unclear if the threat environment was the same. The Luftwaffe had suffered a morale dip around the times the USAAF arrived in the Middle East. There were more FW 190s operational in NW Europe and probably more flak.

So while I might tend toward the P-40 due to the combat histories, I couldn't claim to know definitively which one was better. I do think they are comparable which is more than some would admit. However if it turns out that the Typhoon really did turn and roll well then I would give the nod to the Typhoon. The only real advantage of the P-40 seems to be maneuverability.

 

[Zipper730]

You are over complicating things. especially #3

Most props (once you get rid of the fixed pitch and two pitch things) are just about 80% efficient give or take (mostly take) a couple of points. That was the whole idea of the constant speed propeller.

I knew 80% efficiency was a figure at certain speeds, and never connected that data with the constant-speed propeller. I figured the constant-speed propeller did allow the efficiency of the propeller to be varied for speed.

Since the conversion of engine thrust to power varies with the speed of the aircraft there is a considerable reduction in "power" at climb speeds compared to max level speeds.

Of course -- that variation is proportional to speed?

We don't need to know cooling drag, that goes right in with over all drag. yes a plane in climb mode (cooling flaps and doors open and hanging in the breeze) is very dirty compared to one closed up for high speed but then instantaneous drag goes up with the square of the speed. Power needed goes up with cube of the speed.

This might sound silly but why does drag go up with the square of speed and power needed go up with the cube?

Want to check your "thrust" calculations at 140-160mph climbing speed?

That was kind of what I was going for. While this might sound silly could I simply use the TAS of the airplane to do a rise over run sort of thing where I factor the speed in fps; then compute climb-rate in fps at that speed and use the slope equation to just figure out how high-up the nose is pointed and then use that to establish a power-to-weight ratio (T/W of 0.5 = 45-degree maximum climb which is 1/1).

As I posted earlier, I think the RAE and NACA graph we all use as gospel may not be giving the full picture for one reason or another re: the Typhoon roll.

...

In service, if the Typhoon's roll rate over 250 IAS compared best with a Spitfire with fabric ailerons (and a lot worse under that) than any other fighter -- you'd think this wouldn't escape constant mention.

I didn't even think of that variable. That said, what was the roll-rate of the Spitfire using fabric covered ailerons?

 

[Schweik]

I didn't even think of that variable. That said, what was the roll-rate of the Spitfire using fabric covered ailerons?

Not fantastic but much better than the Typhoon according to this which Ivan already posted upthread.

 

[Shortround6]

I knew 80% efficiency was a figure at certain speeds, and never connected that data with the constant-speed propeller. I figured the constant-speed propeller did allow the efficiency of the propeller to be varied for speed.

That is one chart, others may differ a bit (not go over 80%?) but basically the constant speed propeller will have a good efficiency over quite a speed range.

This might sound silly but why does drag go up with the square of speed and power needed go up with the cube?

Drag is the force acting at one one moment. Or perhaps the resistance to force at any one moment?
Power introduces a time element. Plane A for instance is going 20 % faster than Plane B. It needs 44% more force at any one moment in time. However if you change the speed of plane A by 20 % it is trying to cover more ground (move aside ) 20% more air in the same amount of TIME as the slower plane, in addition to moving the air aside faster and the higher friction impact. Stick arm out of car window at 40mph and 50mph. more force acts on the arm in any one moment and keeping the arm out there is going to require a lot more work (muscles get more tired) in the same amount of time

 

[Zipper730]

View attachment 525845
That is one chart, others may differ a bit (not go over 80%?) but basically the constant speed propeller will have a good efficiency over quite a speed range.

I know J is advance-ratio, what's 0.75R, and that funny looking N sub pe on the y-axis?

Drag is the force acting at one one moment. Or perhaps the resistance to force at any one moment?

I follow

Power introduces a time element. Plane A for instance is going 20 % faster than Plane B. It needs 44% more force at any one moment in time.

I figured force would be based on surface area, (L x W), but we live in a 3D world so you have L*W*H. I figured it'd have all cubed up.

Disclaimer: I was born in the early 1980's and as a result went to school during the late 1980's to early 2000's. Our education and curriculum suck.

 

[Dan Fahey]

This stuff about 'tuning the engines" is a pet peeve of mine.
Just what the heck did they do to "tune' the engines?
The ignition timing is fixed. The valve timing is fixed. the intake track is fixed, you have very very limited options on the exhaust stacks.

You can change the jet size in the carburetor/injector but most aviation fuel (at least from the same country) had pretty much the same BTUs per gallon/pound so screwing around with the mixture isn't going to get you much.

That leaves messing around with the boost control, which really isn't "tuning" an engine in the conventional sense.

US 100 octane used 2% or less aromatic compounds and the rich response of the fuel didn't change much from the lean response. It was sort of 100/98-102 fuel.
British BoB fuel was 100/115-20 and had no less than 20% aromatic compounds.
The high aromatic compound fuel would dissolve certain rubber parts in the fuel system and degrade early self sealing tank liners so the number of early US fighters that used the two different fuels is limited. US agreed to go to the high aromatic fuel even before Pearl Harbor so fuel incompatibility wasn't really a problem. Neither was "tuning" the engines once they left the United States,

I race cars and have for more than 40 years.
On the Allison and Merlin engines you can adjust the Magneto's for more/less Timing then matching the Jetting for the Fuel and Boost Used.
The jetting was designed to match the Specific Gravity of the fuel.

British increased the Boost on the early Mustang and P40 especially focused attacking French and German targets.
The Brits stated the aircraft behaved much better with increased Boost..
Did they use the US 100 Octane or British 100/130...in the MTO and CBI ?

 

[Schweik]

I believe the Desert Air Force did use 100/130 fuel in the Med but I'm not sure precisely when that started.

For the CBI I am not sure but most of the supplies came via India which at the time was part of the British Commonwealth.

 

[wuzak]

Drag is the force acting at one one moment. Or perhaps the resistance to force at any one moment?
Power introduces a time element. Plane A for instance is going 20 % faster than Plane B. It needs 44% more force at any one moment in time. However if you change the speed of plane A by 20 % it is trying to cover more ground (move aside ) 20% more air in the same amount of TIME as the slower plane, in addition to moving the air aside faster and the higher friction impact. Stick arm out of car window at 40mph and 50mph. more force acts on the arm in any one moment and keeping the arm out there is going to require a lot more work (muscles get more tired) in the same amount of time

I know J is advance-ratio, what's 0.75R, and that funny looking N sub pe on the y-axis?
I follow
I figured force would be based on surface area, (L x W), but we live in a 3D world so you have L*W*H. I figured it'd have all cubed up.

Disclaimer: I was born in the early 1980's and as a result went to school during the late 1980's to early 2000's. Our education and curriculum suck.

Drag is the force resisting motion of a body through a fluid.

Power is the rate of doing work. Ie P = W/t

Work done by a force is equal to the force multiplied by the displacement. ie W = f * d

So, P = (f * d) / t or f * d/t = f * v

Drag force is proportional to the square of the velocity. ie Fd = k * v^2

So power P = k * v^2 * v = k * v^3

Of course the drag equation only works in certain situation, and certainly not very well at higher mach numbers.

 

[Shortround6]

Thank you.

 

[Dan Fahey]

I believe the Desert Air Force did use 100/130 fuel in the Med but I'm not sure precisely when that started.

For the CBI I am not sure but most of the supplies came via India which at the time was part of the British Commonwealth.

That is important...because the mechanics adjusted maximum boost for more power.
But just not for WEP it was used at Military power which allowed them to operate at a higher speed. Making them more competitive with Axis fighters.
The Density Altitude of summer weather killed HP..
Can document as much as 4 tenths improvement in my Stocker in the 1/4 mile on Cold air day at sea level track compared to hot day.
In Russia the density altitude in cold weather can see being well below 1500 ft below sea level.
The cold fuel able to keep temperatures lower under combat power.
Compared to the DA of the hot desert that could have been 3000 above sea level.
The Me 109 did not use near the boost or rpm of the Allison or Merlin

 

[wuzak]

Thank you.

You're welcome.

 

[Glider]

I believe the Desert Air Force did use 100/130 fuel in the Med but I'm not sure precisely when that started.

For the CBI I am not sure but most of the supplies came via India which at the time was part of the British Commonwealth.

The RAF in the desert used 100/130 fuel for combat operations from about May 1940 onwards, maybe a slight delay in the furthest reaches of the war by a couple of months. But for the period we are talking about it was exclusive.

 

[Ivan1GFP]

As I posted earlier, I think the RAE and NACA graph we all use as gospel may not be giving the full picture for one reason or another re: the Typhoon roll.

(re: my earlier posts here)
Which is the better fighter, P-40F or Typhoon?
Which is the better fighter, P-40F or Typhoon?

Hello Greyman,
Those posts do give an alternative OPINION of the relative maneuverability of the Typhoon.
What they don't give is an quantitative view of the performance.

As Schweik brought up, the P-47 Thunderbolt also has a pretty good reputation for roll rate but the actual numbers suggest roll rate was not particularly good. Schweik also commented that the P-51 Mustang had an Excellent roll rate, but if you check the graph and review other accounts, you will find that this "Excellent Roll Rate" was only at high speed. At lower airspeeds, it is pretty similar to Typhoon.
Many tactical descriptions disparage the roll performance of the A6M series and describe how US Navy fighters used their faster roll rates to defeat the Type 0 Fighter. This can be contrasted with modern pilots who have flown both the Hellcat and A6M and state in interviews that the A6M rolled much faster. Videos can also be found which show very good rolling performance by the A6M5.
Assuming that everyone is being honest, how does all this fit together?
It seems to me that everyone is telling the truth, but the evaluation criteria are quite different.

The graph I posted is just one snapshot of relative performance under very specific conditions: 50 pounds of Stick force at 10,000 feet altitude for a STEADY STATE Roll. Some other tests use 30 pounds of force on the stick. Some are done with only 1/4 aileron deflection. Perhaps other folks are looking for responsiveness.
If measured under those other conditions, perhaps Typhoon does better. Under the conditions listed in this graph (which are fairly common test conditions), Typhoon did relatively poorly.
The P-38 Lightning with boosted ailerons would have also done well in this test for steady state roll, but pilot reports often mention the terrible lag in response, so how would you judge that kind of rolling performance?

In service, if the Typhoon's roll rate over 250 IAS compared best with a Spitfire with fabric ailerons (and a lot worse under that) than any other fighter -- you'd think this wouldn't escape constant mention.

Perhaps if the pilots had flown the Typhoon in the air superiority role, they would have commented on the poor roll rate. Keep in mind that the greatest use of the Typhoon was in the ground attack role in which a poor roll rate may not be so obvious and certainly would not be noticed while carrying ordnance.
One also has to wonder why the Typhoon as the fastest (at low altitude) and most modern fighter in the RAF inventory got pushed to the role of mud mover. Perhaps its shortcomings in air-to-air combat were obvious.
As for escaping constant mention, the Typhoon also had some serious compressibility issues but one doesn't hear much about those either because it generally wasn't operated in a way that would manifest those.

- Ivan.

 

[Ivan1GFP]

Not fantastic but much better than the Typhoon according to this which Ivan already posted upthread.

Hello Schweik,
That graph I posted shows a Spitfire Mk.V with clipped wings and with full span wings but both have metal ailerons.
The Spitfire with Fabric covered ailerons had much inferior rolling performance at high speed.

- Ivan.

 

[Greyman]

I'm basically on the same page, I think. As I said earlier, a simple, steady rate with 50 lb force 'may not be giving the full picture'. When you read all the opinions from the A&AEE, USAAF, and AFDU what you don't see is "this is the worst rolling aircraft at any speed this establishment has ever seen". So I'm fully prepared to believe there's more nuance to roll performance than steady rate at 50 lb force.

Re: the Zero, that can easily be explained by speed. Under 250 IAS (according to Allied tests) the Japanese fighter handily out-rolled the Wildcat/Hellcat - above that speed the US fighters held the advantage.

I'm fairly certain the Typhoon was used for ground attack over the Spitfire more due to superior lifting capacity and inferior high-level performance (vs. the Spit IX). Though I'm sure the Spitfire's superior climb and manoeuvrability played a part.

I would probably disagree about the compressibility issues - if we're talking about the same thing. Typhoons were routinely dived at high speed while bombing.

Quick photoshop of the fabric-aileron performance of the Spitfire:

 

[Ivan1GFP]

I'm basically on the same page, I think. As I said earlier, a simple, steady rate with 50 lb force 'may not be giving the full picture'. When you read all the opinions from the A&AEE, USAAF, and AFDU what you don't see is "this is the worst rolling aircraft at any speed this establishment has ever seen". So I'm fully prepared to believe there's more nuance to roll performance than steady rate at 50 lb force.

Hello Greyman,
I suspect that the ailerons on Typhoon were very responsive and for a plus or minus 45 degrees roll test gave a good impression but the peak roll rate was just as low as shown in the graphs. Depending on what the pilot is looking for, that could be seen as quite good or quite bad.

Re: the Zero, that can easily be explained by speed. Under 250 IAS (according to Allied tests) the Japanese fighter handily out-rolled the Wildcat/Hellcat - above that speed the US fighters held the advantage.

Take a look at how the Japanese Zero performs according to the graph and then look for one of the you-tube videos of a A6M5 in flight. The times I was getting with a stopwatch did not even come close to what would be expected from the graph shown here.
Note also that the A6M had very long span ailerons and that was probably done for a reason.
It would be extraordinarily stupid for a designer to put a feature like that in an aircraft without some benefit.

I'm fairly certain the Typhoon was used for ground attack over the Spitfire more due to superior lifting capacity and inferior high-level performance (vs. the Spit IX). Though I'm sure the Spitfire's superior climb and manoeuvrability played a part.

Perhaps. Consider though that the Spitfire did not have much internal fuel capacity and not much load lifting capacity as you mentioned. Why not use the Typhoon as a long range fighter carrying a couple large drop tanks instead of committing them all to the ground attack role? My BELIEF is that it wasn't really a competitive fighter and that was the reason the Tempest was developed so quickly to address Typhoon's shortcomings.

I would probably disagree about the compressibility issues - if we're talking about the same thing. Typhoons were routinely dived at high speed while bombing.

Compressibility tends to be a high altitude thing. As long as the Typhoon stayed below about 8,000 feet, the air was dense enough and the speed of sound was high enough that there was no loss of control. The Thunderbolt had a very similar problem at high altitude but not at low altitude.

- Ivan.

 

[Greyman]

Why not use the Typhoon as a long range fighter carrying a couple large drop tanks instead of committing them all to the ground attack role?

It was uncompetitive over about 15 thousand feet. You can't base an ETO RAF fighter force on that.

Re: Zero roll ... I added 50 lb stick force roll (A6M3) from an RAAF document. It had both right and left rolls -- I eyeballed the two curves and drew a line between them. The NACA graph seems to use a stick force of 20lb (at best) for the Zero.