P-40 Warhawk/Kittyhawk

[pbfoot]

Just listened to Stocky Edwards around 20kills and he said the P40 stated off with 2 250lbs bombs but later used 2 500lb bombs an interesting thing in this vid is he says the wing guns used to jam after pulling g's about 3-4 minutes into the following vid anyone else ever hear of this

View: https://www.youtube.com/watch?v=p_umy5aRfLw

 

[Glider]

A P40 with 6 x 250lb bombs
File03372.011 kittybomber.jpg - Wikipedia, the free encyclopedia

 

[Vincenzo]

Max bomb load for P-40N was 2*1000 pounds (wing) and 1*500 (belly)
F&L can load 1*600 in belly position and 6*30 in wing position it's not told if both. D&E can load the six small in the wing and a 500 in belly (as above for both)

 

[Clay_Allison]

would a near miss by a 250lb bomb kill a Panzer?

 

[Ivan1GFP]

There are a few misconceptions floating around in this discussion about the various aircraft in this discussion: The P-40, P-51, A6M Zero and to a very small extent, the Hurricane.

The A6M Zero was NOT a draggy plane as has been claimed multiple times. It was actually a very slippery and aerodynamic aircraft. Consider the speeds it achieved with VERY LITTLE installed power. The restriction on diving speed was structural strength. Increasing the gauge of the skinning was the means of increasing the dive speed of the late model A6M. The Zero was also probably not as slow as I have seen in one of the graphs posted here. Consider that a Model 21 in US Navy tests was able to achieve 332 mph even though it was admittedly (Cdr Hoffman) not quite 100%. Also worthy of note is the manifold pressure settings used to achieve this speed. It was NOT running "Overboost" or "WEP" during the USN tests. A fairly thorough examination out at J-aircraft puts the max speed at 345 mph at altitude.

The P-40 and P-51 are radically different as far as drag. Folks here keep comparing the Allison engined P-40 and the Merlin Mustangs. There is a much more direct comparision. The early Allison Mustangs (P-51, A-36, F-6, P-51A) were quite fast aircraft down low. The P-51A was actually faster than the later P-51B and P-51D up to about 15,000 feet IIRC. The P-51 was faster than the P-40 by about 40 mph with similar installed power. Compare the P-40E and the P-51 (350 vs 390). Compare the P-40N with the P-51A (375 vs 415). Don't feel bad though: The Spitfire was also about 30 mph slower than the P-51 with very similar engines (Spitfire IX - 410 mph, P-51B - 440 mph).

In my opinion, the P-51 was not a particularly rugged airframe. Consider that the A-36 eventually had its dive brakes wired shut because at high speed, the stress sometimes ripped the wings off. A P-51B structural failure in a dive killed the pilot Tommy Hitchcock. Apparently a door over the gun installation deformed enough to change the airfoil shape and overstress the wing. The P-51B and P-51D did NOT have quite the same airfoil shape or handling according to at least one pilot quoted in a book by John Dibbs. (I can find the reference if anyone is curious.) This pilot continued to fly the B/C after his unit switched to the D model.
The change from Razorback to Bubbletop made the plane LESS streamlined AND also less directionally stable. The fin extension was one attempt to cure the problem. The longer fin on the P-51H was another attempt.

One of the things that I keep seeing mentioned is how the Me 109 had a great amount of stretch that it served throughout the war. I believe that there was enough difference between the 109E and 109F to deserve an entirely new designation. Compare the two aircraft. There isn't much that carried through from the E to the F.

Hope I haven't insulted anyone here.
- Ivan.

 

[wombat40]

Try to obtain a copy of "Pacific Hawk" by John Vader (Purnells History of WW2 series)
Seems that there was an attempt to fit a RR engine to the P40. Remember too that the first Mustangs were fitted with Alisons and designated A 36. They still outperformed the P40, design plays a part in performance, not just engine size and type

 

[HoHun]

Hi Ivan,

>The Zero was also probably not as slow as I have seen in one of the graphs posted here. Consider that a Model 21 in US Navy tests was able to achieve 332 mph even though it was admittedly (Cdr Hoffman) not quite 100%. Also worthy of note is the manifold pressure settings used to achieve this speed. It was NOT running "Overboost" or "WEP" during the USN tests. A fairly thorough examination out at J-aircraft puts the max speed at 345 mph at altitude.

Hm, I guess you're thinking of my graph. However, I have compared all available data sets carefully and don't think there is much potential for the A6M to have been significantly faster than my calculation.

My calculation also takes the use of war emergency power into account, so I have to reject that aspect of your criticism.

Do you have a link to the examination you mention? If it's Richard Dunn's, I found it to be quite interesting, but don't think it's methodically good enough to warrant conclusions regarding any specific A6M top speed.

Regards,

Henning (HoHun)

 

[FLYBOYJ]

The A6M Zero was NOT a draggy plane as has been claimed multiple times. It was actually a very slippery and aerodynamic aircraft. Consider the speeds it achieved with VERY LITTLE installed power. The restriction on diving speed was structural strength. Increasing the gauge of the skinning was the means of increasing the dive speed of the late model A6M. The Zero was also probably not as slow as I have seen in one of the graphs posted here. Consider that a Model 21 in US Navy tests was able to achieve 332 mph even though it was admittedly (Cdr Hoffman) not quite 100%. Also worthy of note is the manifold pressure settings used to achieve this speed. It was NOT running "Overboost" or "WEP" during the USN tests. A fairly thorough examination out at J-aircraft puts the max speed at 345 mph at altitude.

Although the Zero was able to attain those speeds, it handled like a brick at speeds over 300 mph. At speeds between 250 - 275 mph is when the Zero was at its best; above that the ailerons were heavy and the aircraft lost its maneuverability advantage.

One of our members is a CAF member and their chapter has owned a few Zeros, this was echoed by the pilots who flew them.

 

[Ivan1GFP]

Hello HoHun,

I am still trying to find Intelligence Brief #3 for details about the testing of the Aleutian Zero. I agree with you that the argument by Richard Dunn is a bit optimistic, but the throttle settings used in the test are probably accurate.
BTW, The 98% comment I attributed to Cdr Hoffman was by Admiral Saunders. (My inaccurate recall.)

Hello FLYBOYJ,
Just for grins, Look for YOU-TUBE videos of the Zero and Oscar. I believe most of the Zero videos are of the CAF A6M5. Use a stopwatch while watching the videos. The actual filmed roll rates may surprise you. They surprised me! Unless these films are faked, these planes roll a whole lot faster than most folks think they do. Seems to me that 150-250 mph is a more ideal speed range for these planes.

- Ivan.

 

[FLYBOYJ]

Hello FLYBOYJ,
Just for grins, Look for YOU-TUBE videos of the Zero and Oscar. I believe most of the Zero videos are of the CAF A6M5. Use a stopwatch while watching the videos. The actual filmed roll rates may surprise you. They surprised me! Unless these films are faked, these planes roll a whole lot faster than most folks think they do. Seems to me that 150-250 mph is a more ideal speed range for these planes.

- Ivan.

I agree with the roll rates (especially with the Oscar) and stand corrected on the best maneuvering speeds. Point here is that when either aircraft is forced to fight at higher airspeeds the advantages of the Japanese aircraft are greatly diminished. As we've all heard on countless occasions, the Flying Tigers proved this with little doubt.

I saw a demo at Chino back in the early 80s - a Zero against an F4U. At lower airspeeds in the horizontal the Zero had an advantage out turning the F4U. As soon as both aircraft continued their demo at higher airspeeds, the Corsair went into the vertical and used a high yo-yo to his advantage. The Zero could not shake him.

Lastly at the end of the day, always consider the skill of the pilot as that could throw all performance estimates out the window.

 

[Marshall_Stack]

Consider that the A-36 eventually had its dive brakes wired shut because at high speed, the stress sometimes ripped the wings off.

Not that it matters much (especially for this discussion), but I have read many times that having the dive flaps wired closed was a myth. Reading accounts from A-36 pilots seems to support this as a myth.

 

[Ivan1GFP]

Hi FLYBOYJ,
I believe we are generally in agreement. Keep in mind that a modern flight exhibition may not be entirely representative of wartime performance though the conclusion from this demo seems quite reasonable. No one is running their engine at maximum performance and no one is going to pull enough G in their WW2 senior warbird to black out.

A modern WW2 warbird is probably MUCH lighter than the wartime version. Self sealing fuel tanks, armour, guns, ammunition, bomb racks, plumbing for external tanks, ancient radios and the like are typically deleted which makes at least the US warbird much more agile.

Hello Marshall_Stack,
I have not researched the topic of dive brakes other than in the last couple hours after seeing your message. I just read in one of the Mustang books that structural failure was the reason for wiring the dive brakes. Your account seems to be the correct one, though I will still check through a few books to see if I can find the A-36 structural failure reference.

- Ivan.

 

[FLYBOYJ]

Hi FLYBOYJ,
I believe we are generally in agreement. Keep in mind that a modern flight exhibition may not be entirely representative of wartime performance though the conclusion from this demo seems quite reasonable. No one is running their engine at maximum performance and no one is going to pull enough G in their WW2 senior warbird to black out.

From sme of the single engine warbird owners I've met, sonme of them are limited to 3.5 Gs either by feds or self imposed.

A modern WW2 warbird is probably MUCH lighter than the wartime version. Self sealing fuel tanks, armour, guns, ammunition, bomb racks, plumbing for external tanks, ancient radios and the like are typically deleted which makes at least the US warbird much more agile.

Way lighter. Just the radios alone could mean upwards of a few hundred pounds.

 

[JoeB]

Consider that a Model 21 in US Navy tests was able to achieve 332 mph even though it was admittedly (Cdr Hoffman) not quite 100%. Also worthy of note is the manifold pressure settings used to achieve this speed. It was NOT running "Overboost" or "WEP" during the USN tests. A fairly thorough examination out at J-aircraft puts the max speed at 345 mph at altitude.

We must generally accept the fact that top speeds of WWII fighters under real combat conditions are still uncertain. In many cases apparently equally valid data disagrees. To make a single graph of course we must reject one conflicting datum or another, but that doesn't make the graph a single fact which surely correctly describes the situation. In general, the speeds of Japanese fighters in optimal conditions probably tended to be understated; by a very significant degree? not necessarily, and there's always actual performance in combat v ideal conditions (especially later in the war), but there is that tendency, and j-aircraft has been a good place to read about it over the years.

One thing the Zero could and often did do with perhaps understated speed was use energy tactics, which the JNAF did use contrary to myth even in 1942, when it had an altitude advantage. Most one on one analysis, and any fair flight demo, would tend to assume equal starting points for both fighters but of course that was seldom true of any given actual combat. So one key feature of a fighter was how well it might exploit an initial advantage to shoot down another fighter, v how well it might parry an initial disadvantage to avoid being shot down itself, seeking just to fight another day in that case. It might use different tactics or strengths depending which of those situations it was in.

Joe

 

[slaterat]

Joe B wrote

Most one on one analysis, and any fair flight demo, would tend to assume equal starting points for both fighters but of course that was seldom true of any given actual combat. So one key feature of a fighter was how well it might exploit an initial advantage to shoot down another fighter, v how well it might parry an initial disadvantage to avoid being shot down itself, seeking just to fight another day in that case. It might use different tactics or strengths depending which of those situations it was in.

That might be the truest words ever written on this forum.

Slaterat

 

[Ivan1GFP]

This is a minor change of subject, but I believe it is directed to a pretty good audience:

What is the length of the P-40B/C and P-40D/E?

From what I have found (without having the actual aircraft to measure),
the P-40B/C is 31 feet 8-Something inches
the P-40D is supposed to be about 6 inches shorter: I have seen numbers stating 31'2". The diagram in the Schematics area shows 31'7". America's Hundred Thousand says 31'8.5".

Which is correct? How can I confirm?
- Ivan.

 

[drgondog]

This is a minor change of subject, but I believe it is directed to a pretty good audience:

What is the length of the P-40B/C and P-40D/E?

From what I have found (without having the actual aircraft to measure),
the P-40B/C is 31 feet 8-Something inches
the P-40D is supposed to be about 6 inches shorter: I have seen numbers stating 31'2". The diagram in the Schematics area shows 31'7". America's Hundred Thousand says 31'8.5".

Which is correct? How can I confirm?
- Ivan.

Curtiss P-40D

All changes due to the 1710-39 engine resulting in a Thrust line change, as well as a shortened nose - adapted for all subsequent models.

 

[Ivan1GFP]

Thanks Drgondog,

Your reference is one of the conflicting sources.
Earlier in the series you listed is this:
Curtiss P-40

Length is 31' 8 3/4" so Length of D/E would be 31' 2 3/4"

Please refer to the diagram at this discussion:
http://www.ww2aircraft.net/forum/schematics/p-40d-drawing-12109.html

Length is 31' 7"

If the diagram is in error, where is the error?

- Ivan.

 

[drgondog]

Thanks Drgondog,

Your reference is one of the conflicting sources.
Earlier in the series you listed is this:
Curtiss P-40

Length is 31' 8 3/4" so Length of D/E would be 31' 2 3/4"

Wiki had the E at 31.67 - which would be ~ 31' 8".

Please refer to the diagram at this discussion:
http://www.ww2aircraft.net/forum/schematics/p-40d-drawing-12109.html

Length is 31' 7"

If the diagram is in error, where is the error?

- Ivan.

Without access to Curtiss plan with full dimensions I don't know how you will reconcile the differences in the Wiki/Baugher, etc write ups

 

[Ivan1GFP]

Hello Drgondog,

Now you see the problem. The schematic was supposedly based on Curtiss drawings and information compiled by William Wylam. The origin of the information from the other two sources is unknown. I am hoping someone can point me to a provably correct source.

- Ivan.