Which is the better fighter, P-40F or Typhoon? (1 Viewer)

[Schweik]

I think it means risk of blackout due to G forces at the very least.

The dive characteristics of the P-40 are no mystery. There was no compressibility or flutter, no real problems with the control. It was the same issue on takeoff at full power - you had to use a lot of rudder and you needed to trim it out to be comfortable.

I am no pilot, but from reading the memoirs of the pilots who flew them I would suggest the reason you wouldn't want to use maximum trim is because once you are out of your dive you have to trim it back again. It's best if you don't need to use trim at all but it's good to have the option.

I am Ok with some of y'all not believing they routinely dived at 500 mph - but I am thoroughly convinced. Pilots like Greg Boyington, Robert Scott, Phil Adair, James Edwards, Nicky Barr, Bob DeHaven, Benjamin O Davis and too many 325th, 79th and 57th pilots to keep all their names strait all mentioned diving the P-50 at 500 + mph - as I have pointed out repeatedly it was a standard escape maneuver widely used in the Pacific and also used in the Med and Middle East.

The test pilot also did this in checkout flights routinely on 2400+ aircraft. That is convincing enough for me.

We also know the manual is overly conservative, at least compared to wartime conditions, on many things and not just maximum dive speed. Boost settings also kept inching upwards in the manuals both for Allison and Merlin engined fighters, and yes by the way they did overboost the Merlins as well.

 

[Schweik]

Routinely exceeding limitations is not a good business practice with planes. It will bite you in the arse eventually, or worse the guy who flies it last. Your attitude towards what you think the limits of the aircraft should be based on what one guy did with a brand new airplane would not for a long combat career make.

Again, I don't think they would do that in a checkout flight if it was really risky to the airplane. His actual quote was something like "there is no way to damage a P-40 by stressing the airframe" which I'm sure is an exaggeration but the real threat there for a newer pilot would be to get into a bad spin I think (or black out and auger in)

Airspeed installation error, out diving the enemy (Zeros in your one example - does not mean they dove to their max speed every time) is not as convincing to me as it is to you. From knowing what I do about Zeros I would not be anxious to get one fast in a shooting match as I would feel like I was running around with my skirt up asking to get spanked. Terrible roll rate and very stiff stick is not it's forte, so when a P40 rolled over and took the elevator down I would let it go (which would further reinforce the speed in dive advantage) but doesn't mean the Allied pilot was doing 500+.

Cheers,
Biff

No it doesn't, certainly not every time, but they weren't taking chances and from reading their accounts, I suspect many of them dove absolutely as fast as they could - it sounds like you had to get to very high speed to get away especially from the Ki-43s by the way (and they couldn't always tell the difference). Keep in mind that hundreds of Allied aircrew were dying right and left in fights with Japanese aircraft, in the Philippines, Java, it was a "bloody shambles" to use Christopher Shores apt title, and the stiffening of the resistance at Milne Bay and New Guinea and Darwin was a very close run thing with extremely high casualties (upwards of 70% for some Australian Squadrons).

From the wiki for 75th FS RAAF:

"No. 75 Squadron's casualties quickly mounted and were exacerbated by high rates of disease.[4] Squadron Leader Jackson was shot down and killed on 28 April, shortly after he had destroyed a Japanese fighter.[6] His younger brother Squadron Leader Les Jackson assumed command the next day. By the time two USAAF squadrons arrived to reinforce it on 30 April, No. 75 Squadron had been reduced to just three serviceable aircraft and a further seven Kittyhawks in need of repair. The squadron was withdrawn from operations on 3 May after losing two aircraft the day before. During its period at Port Moresby No. 75 Squadron was confirmed to have destroyed 35 Japanese aircraft, probably destroyed another four and damaged 44. The squadron suffered twelve fatalities and lost 22 Kittyhawks, including six in accidents "

I have also read interviews how almost all of them had dysentary so bad they had to tape their pants shut over their boots so sh*t didn't get all over the cockpit. They also mentioned diving from 25,000 ft down to near sea level and then climbing back up again wasn't fun when you had dysentary gas bubbles in your guts. In short conditions were horrible, life was cheap, essentially, and these guys were fighting to their utmost limits and well beyond. It wasn't much better in the Middle East.

The thing about all these dichotomies between performance in the manual guidelines vs. pilot accounts - is that the aircraft lets remember, was not sufficient to survive in against a Zero, a Ki-43 or a Bf 109 or an MC 202 - all excellent aircraft, if flown according to the limits that the manufacturer and the Army thought were reasonable and wise. And the pilots generally were not as well trained either in the first year or two of the war. Even if they were basically equivalent - you had to push the limits to get an edge otherwise you are going to be facing 50/50 odds. The only way they survived was by routinely exceeding those limits. That is the historical fact. That is what was complained about in the Allison overboosting memo and it's what was described by so many of the pilots. They had to figure out how to push the envelope to be competitive. And this in fact was one of the strengths or merits of the P-40: that they were able to do so and survive. This is one of the main traits it was praised for by pilots "it would get you home". I believe that is what they meant.

Luckily for Anglo-American (Aussie, Canadian, NZ, South African etc.) pilots, they had this remarkable Company test pilot Herbert Fisher who knew the exact limits of the aircraft very well and spent a year going around to "every airbase in the CBI, Africa and the Middle East" to paraphrase what I already quoted upthread, and even flew combat missions, to show them how to get away with pushing the aircraft to the edges of it's envelope. Not for his health I'm sure and I hope he didn't get Marlaria in the process. But because knowing exactly how far you could push the limits was very important for success and success meant survival in the sense of not being torn apart by cannon shells for those 22 year old combat pilots. They also had the good fortune to have fellow pilots like Nicky Barr among them who figured out how to pull G without blacking out and learned by experimentation (under the very imminent threat of death by heavy caliber bullets and cannon shells) that he could pull 6 or 7 G's in a P-40, and showed others how to do it.

War is extremely demanding and stressful, on men and machines. Almost all WW2 fighters, certainly Allied fighters in the early War, routinely had to be pushed to their limits and beyond in order for the pilot to survive. If you have an enemy aircraft right on your tail shooting 20mm cannon shells at you, and your choice is to dive faster and maybe extend away or stick to the manual limits and pull away gradually while hoping he doesn't hit you, in many cases the pilots clearly chose the former option. Obviously they had to walk a fine line because you most certainly still could destroy the plane or go into an uncontrollable spin you can't get out of, and die just the same.

S

 

[michael rauls]

Hello Schweik,

You got me on the bad math thing. 1000+500+500 = 2000 pounds, not 1500 pounds!
Your lightened P-40L would be just past the 10,000 pound maximum T-O weight (for the late P-40) with a 2,000 pound bomb load but under the right field conditions, it sounds plausible.

The diving issue and trim that I was describing wasn't a matter of just reducing control force. It was a being aware that the aircraft may go sideways very quickly and break up. There needs to be some rudder control remaining to counteract the yaw tendency BEFORE the aircraft goes sideways.
I actually had not missed Grayman's post regarding procedures and dive speed limitations.
Please observe that what is listed in the table is max permissible dive speeds and they are not at full throttle.
Manifold pressure is not stated, but engine speed is only 2600 RPM.

Just for comparison's sake, note that the A6M3 has a maximum diving speed of 410 MPH and the A6M5 has a 460 MPH maximum and these were some of the lightweights that the P-40 fought.

- Ivan.

I've read a couple times including quotes from pilots that flew them that getting into the uper 300s in an A6m was asking for trouble including posible structural damage.
Not saying your wrong but but when you listed 460 mph as a max dive speed for them it certainly perked my interest. Could you elaborate?

 

[Milosh]

I think some forgets that the ASI is not that accurate at high speeds, like in a dive.

 

[michael rauls]

I think some forgets that the ASI is not that accurate at high speeds, like in a dive.

True but that would be a constant for all aircraft so any comparisons should still be valid, no?

 

[Schweik]

I think some forgets that the ASI is not that accurate at high speeds, like in a dive.

It's a reasonable point for sure. It's also possible that certain things were just assumed since they were done so often. Memory of combat experiences doesn't seem to have always been super accurate.

 

[Schweik]

I've read a couple times including quotes from pilots that flew them that getting into the uper 300s in an A6m was asking for trouble including posible structural damage.
Not saying your wrong but but when you listed 460 mph as a max dive speed for them it certainly perked my interest. Could you elaborate?

A6M5 is the later war model with the shorter wing

 

[michael rauls]

A6M5 is the later war model with the shorter wing

I guess it had a much higher maximum dive speed than earlier modles?

 

[BiffF15]

True but that would be a constant for all aircraft so any comparisons should still be valid, no?

I know of installation error, but would not assume it's linear from one plane to the next (different types). Or the same type if airspeed indicators were made by different manufacturers.

Cheers,
Biff

 

[michael rauls]

I know of installation error, but would not assume it's linear from one plane to the next (different types). Or the same type if airspeed indicators were made by different manufacturers.

Cheers,
Biff

True, any manufacturing shortcomings in airspeed indicators would varry by manufacturer but the physics that caused what seems to be universal inaccuracy at higher speeds would be.... well universal right?
That the p40 did or did not have a particularly inaccurate airspeed indicator and that this could be used to discount high speed readings to a greater degree than other aircraft would seem to be a seperate issue.
And quite an interesting one i would love to know about. I've never heard or read about the Warhawk having a particularly faulty airspeed indicator but that certainly does not mean that this was not the case.

 

[Schweik]

I guess it had a much higher maximum dive speed than earlier modles?

I really don't know, I know it did have a faster level speed (350 mph vs ~320 for earlier types). Shorter (36' vs. 39') wings would mean less drag which I would think would be better in a dive.

 

[Greyman]

My basic takeaway from the A&AEE tests are that;

Kittyhawk at 440 - 450 mph ASI the aeroplane comes out of the dive and yaws to the right against any force that can normally be applied by the pilot.

Typhoon at 510 mph ASI aileron and elevator controls remain light, rudder moderately heavy. It was considered a faster dive at 525 mph ASI would not have materially affected the control characteristics (the aircraft left the Establishment before last dive could be completed).

 

[Schweik]

That isn't what it actually says. It comes out of the dive against any force applied the pilot - until he put in a little bit of trim. He says he had to apply trim and then he could control it.

And if that was the case why would the manual raise the dive speed to 485?

At 460 mph, with 4 divisions of rudder Trim, he was able to dive the aircraft "without any instability or control surface vibration occurring"

 

[Greyman]

I think a desirable quality in a fighter is that its main controls actually control the aircraft in a dive above 450 mph.

If you're diving at 460 mph ASI - barely controlling your aircraft with trim and I'm behind you at 500 mph ASI with light and effective ailerons/elevator and moderately heavy rudder ... sounds like a sticky situation for you.

 

[Ivan1GFP]

I think it means risk of blackout due to G forces at the very least.

The dive characteristics of the P-40 are no mystery. There was no compressibility or flutter, no real problems with the control. It was the same issue on takeoff at full power - you had to use a lot of rudder and you needed to trim it out to be comfortable.

Hello Schweik,
Most US fighters of the time were built for a maximum of 8G with ultimate structural failure at 12G.
If the pilot is blacked out pulling out from a dive, that would put it pretty close to the 8G maximum depending a bit on the pilot.

The yawing issue at Take-Off is just the opposite of what is going on in a high speed dive.
For one thing, it is in the opposite direction. It is also caused by different forces.

I've read a couple times including quotes from pilots that flew them that getting into the uper 300s in an A6m was asking for trouble including posible structural damage.
Not saying your wrong but but when you listed 460 mph as a max dive speed for them it certainly perked my interest. Could you elaborate?

Hello Michael Rauls,
The diving speed limit varied depending on the model. For the A6M2, those pilot accounts sound pretty accurate.
I just went back to look in the book "Zero" by Robert Mikesh to confirm what I was posting here.
On page 90, it gives a listing of some of the changes between models.
For the A6M5, the shortened wing improved diving speed to 360 kts (414 MPH).
With the A6M5a, the thicker wing skin panels raised diving speed to 400 kts (460 MPH).
The book doesn't explicitly state the following, so it is my interpretation:
The A6M3 Model 32 was the first version to have shortened wings.
There were some A6M?3 produced with the engine configuration of the -3 but the wing configuration of the -5.
The book states that there were probably around 50 or so airframes done this way as prototypes for the A6M5.
....so Some if not all of the short wing A6M3 were good for 360 kts in a dive. My belief is that it was all rather than some.
I intend to look for other sources to confirm.

When the A6M2 that was captured in the Aleutians was tested against US fighters, it was rated as comparable in dive acceleration and maximum diving speed to the F4F Wildcat. How unkind of the Japanese not to supply a manual for reference because the US pilots were certainly exceeding speed limitations to come to this conclusion.

- Ivan.

 

[Ivan1GFP]

True, any manufacturing shortcomings in airspeed indicators would varry by manufacturer but the physics that caused what seems to be universal inaccuracy at higher speeds would be.... well universal right?
That the p40 did or did not have a particularly inaccurate airspeed indicator and that this could be used to discount high speed readings to a greater degree than other aircraft would seem to be a seperate issue.
And quite an interesting one i would love to know about. I've never heard or read about the Warhawk having a particularly faulty airspeed indicator but that certainly does not mean that this was not the case.

Hello Michael Rauls,
There is a really nice story by Corwin Meyer about the speed difference between the Corsair and Hellcat (or lack thereof).
His claim is that it was due to the different locations of the static pressure port on the two aircraft. Airspeed is determined by the difference in pressure between the port at the end of the pitot which is facing into the direction of the airflow and the static port.
The problem he ran into was that under certain flight conditions such as low forward speed and a yaw which presented the static port into the air flow, the ASI would read near Zero.
The point is that if the airflow is not what is expected, the readings may not be what is expected.
it is pretty hard to find a nice clean location to put the sensors that does not get some odd airflow at some speeds.
My understanding is that this is the reason that there are often corrections in the aircraft manual for the readings of the ASI.

When these old and not so sleek propeller planes were going fast, often the local airflow would hit transonic speeds even if the entire aircraft was no where close to the speed of sound. These effects of "compressibility" were somewhat hard to predict and would often put shock waves or reverse airflow past odd parts of the airframe and result in nose tuck, loss of lift, loss of control effectiveness, reduction in stability, etc. Depending on location they may also be giving some odd readings to sensors that are supposed to read outside air pressure.

- Ivan.

 

[Ivan1GFP]

I think a desirable quality in a fighter is that its main controls actually control the aircraft in a dive above 450 mph.

If you're diving at 460 mph ASI - barely controlling your aircraft with trim and I'm behind you at 500 mph ASI with light and effective ailerons/elevator and moderately heavy rudder ... sounds like a sticky situation for you.

Hello Greyman,
Assuming that you are pursuing a P-40 in a Typhoon, WHY would the P-40 try to evade by diving????
Almost anything else would work better. The Typhoon can't turn inside the P-40 to follow and can't roll worth anything.
This is yet another case of playing the stupidest game possible or just trying to get killed.
Then again, if the Typhoon pilot hasn't figured out that dogfighting a P-40 isn't a good idea, he will probably find out pretty quickly.

You are also making the assumption that the Typhoon isn't high enough to encounter compressibility at which point Typhoon has even less control.

The reason the P-40 would be diving away from a Japanese fighter is because it almost certainly can't out turn the other guy and may not be able to out climb or out roll him either depending on what the Japanese fellow is flying.

- Ivan.

 

[michael rauls]

Hello Michael Rauls,
There is a really nice story by Corwin Meyer about the speed difference between the Corsair and Hellcat (or lack thereof).
His claim is that it was due to the different locations of the static pressure port on the two aircraft. Airspeed is determined by the difference in pressure between the port at the end of the pitot which is facing into the direction of the airflow and the static port.
The problem he ran into was that under certain flight conditions such as low forward speed and a yaw which presented the static port into the air flow, the ASI would read near Zero.
The point is that if the airflow is not what is expected, the readings may not be what is expected.
it is pretty hard to find a nice clean location to put the sensors that does not get some odd airflow at some speeds.
My understanding is that this is the reason that there are often corrections in the aircraft manual for the readings of the ASI.

When these old and not so sleek propeller planes were going fast, often the local airflow would hit transonic speeds even if the entire aircraft was no where close to the speed of sound. These effects of "compressibility" were somewhat hard to predict and would often put shock waves or reverse airflow past odd parts of the airframe and result in nose tuck, loss of lift, loss of control effectiveness, reduction in stability, etc. Depending on location they may also be giving some odd readings to sensors that are supposed to read outside air pressure.

- Ivan.

Yes ive read that quote about the speed of the Helcat and Corsair. Always wondered if it were indeed true.
My point about the inaccuracies of the airspeed indicator on the p40 were that in absence of any evidence that the p40 had
defect in this regard more so than other aircraft then the fact that speed readings would be off at higher speeds would be the same as other aircraft by way of comparison lest we discount the comparitive high speeds of all ww2 aircraft including say the p51 and Me262. Can't have a standard of critical analysis that only applies to the p40.

 

[DerAdlerIstGelandet]

Any chance we could make this a poll?

Only took 4 months, but there you go...

 

[wuzak]

Only took 4 months, but there you go...

100% for the Typhoon so far. Case closed!