A Critical Analysis of the RAF Air Superiority Campaign in India, Burma and Malaya in 1941-45

One set is for WEP and the other is for military power.

Using the same "criteria" as your post (not saying it is your criteria) the Allison -39 used in the P-40E had two FTHs, one at around 4300-4600ft for WEP and one at 11,500ft for military power, The engine used in the P-40K had one FTH at about 2500ft for WEP and the other at 11,500ftft for military and the P-40 M/N had the WEP FTH at 9500ft and military power at 15,500ft.

In each case it is the altitude at which the throttle can be fully opened and give the rated pressure, above the altitude the throttle is fully open but the supercharger can no longer deliver the rated pressure, below the altitude the throttle has to progressively closed to keep from over boosting the engine.

At about 6000ft the Merlin could give around 1485hp using 14lbs boost (58in aprox) and at 11,000ft it could give at least 1435hp at 16lbs boost (62in aprox) finding the ratings for WEP for the Merlin V-1650-1 is not easy and trying to use the equivalent British engines gets tricky as some of the Merlin XX series differed slightly from each other and the max allowable boost differed both in time (original Merlin XX was re-rated at least twice) and later Series XX engines were allowed to use a boost level that was never approved for the earlier engines.

Thanks Sr6 that is quite informative. Maybe you aren't so bad after all...

MIflyer said:

The P-40N-5 and -40 was actually slower than the E or F but climbed quite a bit faster over over 10,000 ft.
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Not sure about low altitude but the early P-40N (P-40N-1 "interceptor" variant") was the fastest P-40 at ~380 mph at altitude

Oddly enough, the P-40N had both the fastest and slowest production versions of the P-40. The N-1 had the fuel tankage reduced, was cut down to 4 guns, and the starter and battery were deleted. It may have been fast but it was not popular with the operational units.

In 1942 in India they were troubled by a Japanese Dinah recon airplane they could not intercept. Radar warning was not adequate to intercept it and the Japanese felt so invulnerable they would taunt the Allied forces over the radio. They even took one of the F-4's of the 9th Phot Recon unit, added some .50 cal guns and tried to use it as an interceptor. They finally stripped a P-40 down to make it as light as possible and it shot down the Dinah. .

Yay P-40! yeah I agree on all that. They also had a lighter aluminum radiator. They had a few of the faster P-40N production types in use in the Pacific, the RAF didn't get any I don't think. Of course they didn't have to go by what came from the factory. Basically with field modifications you could go 4 guns / less gas (for fighter missions) or 4 or 6 guns / more gas / + bombs (fighter-bomber missions and / or longer range fighter missions).

With 6 guns, the lower rated engine, and extra gas + bombs, the P-40N was a real slow beast, underpowered and ungainly at least until they used up some of the fuel and got rid of the bombs. With 4 guns, the higher rated engine and one of the gas tanks taken out, it was pretty zippy. Most units put back the starter and the battery because it was much faster to start up a squadron during a scramble or even routine operations when you didn't have to use the external one, plus sometimes you needed to restart the engine in flight.



The Australians and New Zealanders, and the US CBI groups still used them a lot as fighters sometimes (and quite effectively) and as fighter bombers too of course, whereas the American Pacific units still stuck with P-40s that late in the game were mostly just using them as fighter-bombers.

RAF in Italy even more so, by 1944 they were not really fighting fighter missions with their Kittyhawk IV's and were pretty much only dropping bombs.

Schweik said:

yeah I agree on all that. They also had a lighter aluminum radiator.

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I believe the oil coolers were also aluminum. Another change was magnesium wheels in the landing gear (and possibly of a smaller size?)

At any rate AHT (Dean) says the P-40N landing gear was about 60lbs lighter than a P-40M.
the Cooling system was about 60lbs lighter, the lubrication system was about 25lbs lighter.
Weights are for a P-40N-25 so the fuel tanks were added back in (but changed to a different type?) as was the electric starter and battery.
For some reason the "communications" catagory had gone up by about 90lbs though.

Might be another one of those IFF things

If they were going to the CBI they probably added a radio direction finder.

Yes, sometimes. You see those also in the Pacific, usually identifiable as a loop in the rear fuselage turtle deck, or as a little fared over teardrop shaped thing. I don't know if there were other kinds.





Photo, warbirdsresource group, pintrest

Shortround6 said:

At about 6000ft the Merlin could give around 1485hp using 14lbs boost (58in aprox) and at 11,000ft it could give at least 1435hp at 16lbs boost (62in aprox) finding the ratings for WEP for the Merlin V-1650-1 is not easy and trying to use the equivalent British engines gets tricky as some of the Merlin XX series differed slightly from each other and the max allowable boost differed both in time (original Merlin XX was re-rated at least twice) and later Series XX engines were allowed to use a boost level that was never approved for the earlier engines.

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This part is intersesting, all I had was 1435 hp for the XX / 1650-1 and that as WEP, I had 1300 as military power. Can you give me the source for these numbers?

Kevin J said:

Are you agreeing by a roundabout way that there were potential problems in jettisoning the slipper type tanks in combat?

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Tom Neil of Malta fame certainly did in his Spit XII. There is a hilarious description of the problem in "From The Cockpit: Spitfire". The Spits had two little hooks under the fuselage just aft of the slipper tank, the idea being that upon release, the hooks would catch the back end of the tank and flip it out away from hitting the Spitfire's tailwheel. Some Spitfire's never had problems, some seem to have almost continual problems caused by those hooks. Neil's XII was a bit of a lemon and the jettisoned tank would continually ram itself onto the hooks, as he put it "standing out rampant from the fuselage", and acting as a big airbrake! Not ideal when you consider the tactics for the Spitfire XII squadrons was to find a group of high-flying Jerries, slip in underneath them, and challenge them to come down to the level the Spit XII's Griffon engines worked best at.

Kevin J said:

…..you'd go up with a big bang if you were hit with even light ack ack?.....

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The USN did a lot of research on exploding drop tanks for the simple reason that carriers have limited space for spares, so they wanted their pilots to only drop their tanks if they really had to. They did slow-motion filming of tanks being shot up and decided it actually wasn't that easy to get them to explode, you have to have the right mix of fuel and air for it to actually go bang. The other thing they found was that, if the tank did explode, it tended to disintegrate into several large but slow-moving fragments that often missed the plane's fuselage or wings due to being thrown clear by the slipstream. Fire could not spread from a lit tank into the plane as there was no oxygen inside the fuel lines. So the USN issued orders that pilots could engage with tanks on and only drop them if desperate to escape. Subsequently, many Hellcats scored victories with their belly tanks still attached. This is in contrast to the RAF, who were very paranoid about fire, and whom actually punished pilots that didn't drop their tanks before engaging the enemy!

Kevin J said:

The Dutch tested a Hurricane in the East Indies with half the armament and fuel and it was fully capable of dog fighting the Hayabusa. The Hurricane had problems with the Hayabusa when it couldn't get to sufficient altitude to combat it i.e. ineffective radar. The Spitfire did stop the Ki-46 overflights but only after the radar cover was up and running. Without effective radar it would not have been able to as the Vc TROP was slower than the Ki-46-II and had a lower rated altitude. Have you read the document attached?

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After a few dogfights with the Japanese, the Hurri pilots over Singapore developed very simple and effective tactics for dealing with the Ki-27 and Ki-43. With the warning of radar, they would take off and just climb for height. The Japanese always seemed to attack at the same time of day and using the same route and height each time, making it easier for the RAF pilots. The Hurricanes would get at least five thousand feet advantage over the Japanese bombers, then go into as steep dives as possible, ignoring the fighter escorts and making one firing pass on the bombers, and carry on the dive until well out of range. The one time a Ki-43 tried to follow its wings folded up. A few of the survivors from Singapore were on Ceylon when the IJN made their Easter Sunday raid. They used exactly the same tactic and all survived, whilst the other RAF and RN pilots that ignored their advice suffered badly at the hands of the Zeros.
Frank Carey was one of the pilots that read their combat reports, and he taught a very simple gunnery course to Hurricane pilots in Burma - get high, let the enemy pass beneath, roll into a vertical dive and rudder until you are making a stern diving attack, make one firing pass and carry on down to the deck. His deflection shooting was legendary and he is reported as shooting down a Japanese fighter with only seven 20mm shells fired.
So, no, the Hurricane was not useless against the Ki-43. Carey's tactics were later used by RAF Spitfire and P-47 units over Burma.

…..but why extend the Spitfire's range when you have Mustangs for the long range escort mission...…….
One driver was when they lost carriers making fighter deliveries to Malta. They actually created the biggest slipper tank in order to enable a Spitfire to fly from Gibraltar all the way to Malta. They had to strip half the guns out of Spit VC, but with the extra fuselage tank and the big slipper they could just make the 1100 mile flight. They started in October in 1942, but by that time the siege of Malta was virtually over, and (IIRC) less than a dozen Spitfires actually made the long flight.

pinsog said:

…..I agree the Hurricane was better than an F4F-4 in mock dogfights. In real life vs a Zero the F4F-4 had a couple of advantages: radial engine, I think it had more/better armor, it did not have a fuel tank in front of the pilot that when punctured soaked the pilot in fuel and lit him on fire.
You may not think a Ki27 is a threat, but your forgetting just how well they turn, they probably rivaled a Gladiator....

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Sorry to disappoint, but the Hurricane did not have a problem with the Ki-43, even at low level. One example was 26th October 1942 over Cox's Bazaar, when Frank Carey (rashly) decided to take off in his IIc when a Japanese raid was attacking the airfield. He was jumped low and slow by the Ki-43 escorts, and spent thirty minutes being chased around by a whole Sentai, yet they didn't manage to hit his aircraft once.
The Hurricane did have a problem intercepting the Dinah, that's one of the reasons the Spitfire was eventually sent to India, and it simply didn't have the range required for escorting the Liberators to Rangoon.

pinsog said:

The problem with the Hurricane vs KI43 is they both play the same game and the KI43 is better. When the Hurricane fought the 109, 110 and even 190 it always had the ability to out turn them. When all else failed a Hurricane pilot could outturm anything the Germans had. When a Hurricane fought KI43's, the turn advantage went to the KI43 by a large margin. They had about the same top speed, climb went to KI43, acceleration went to KI43, the Hurricane wasn't a particularly good diver and if the KI43 was following a Hurricane in a fast dive it could still match the roll rate (unlike the Zero). Other than better firepower in a head on pass I can't think of anything a Hurricane can do that a KI43 can't do better. (The 2nd model of KI43 even had pilot armor and self sealing tanks along with a 2 speed supercharger)

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The Hurricane was not only a good diver, it was relatively easy to recover too. Polish pilots used that to trick 109s into hitting the ground. No Japanese fighter in 1942 could stay in a dive with a Hurricane without risking structural failure when recovering. RAF pilots over Singapore found they could put their Hurricanes into a spiral dive from 25,000ft down to 2000 and recover without problems, and neither the Zero nor the Ki-43 could follow them.
The Ki-43's record is further clouded by rampant overclaiming, even against easier opposition like the Brewster Buffalo. In their first sizeable combat over Malaysia, 22nd December 1941, the Ki-43a of the 64th Sentai jumped the Buffalos of RAAF 453Sq. The Ki-43 pilots claimed 11 victories, but the Aussies actually lost five planes. The one Ki-43 lost had it's wing fold up in a dive, but six of the other Ki-43s had to be grounded upon their return to base because of cracks in their wing spars. And that was a low-level combat.
The fragility of the Ki-43 was amply illustrated on May22nd 1942, when five Ki-43s chased a 60Sq Blenheim out over the Bay of Bengal. The Blenheim's dorsal gunner shot up two of the Ki-43s, sending their pilots back to base wounded, and shot down in flames the Ki-43 of ace Lt Colonel Kato. No armour and no self-sealing tanks meant the Ki-43 simply couldn't take damage, unlike the Hurricane.
Japanese over-claiming was again rampant when 27 Zeros and 101 of the improved Ki-43 IIs, escorting bombers, met 21 Hurricane over Calcutta on December 5th 1943. The Ki-43s claimed six Hurricanes shot down when the RAF actually lost three to the Zeros after the Ki-43s had left the area. The Hurricanes managed to get to the bombers and shot down one Ki-21 and one of the Ki-43s (confirmed by wrecks), despite the overwhelming odds. That's in a combat where the Ki-43s had all the advantages - massive number advantage; height and speed (the Hurricane's best climb speed was 140mph, over a 100mph slower than the cruising speed of the Ki-43s); having to climb while the Japanese could wait up-Sun; snd having to concentrate on the bombers, giving the Japanese fighters freedom to attack as they wanted. Yet the massacre of the Hurricanes you seem to think ought to have happened did not, because the Hurricane was not out-classed by the Ki-43. Even more illuminating is that the three Hurricanes lost that day were from a section of five 176Sq night-fighters, not the day-fighters, and they were actually up looking for the usual post-raid Japanese recce when they were vectored onto a second wave escorted by Zeros. So that's 101 Ki-43s vs 21 Hurricanes and the Hurricanes won.

slaterat said:

…..Overall the Hurricane is the best roller of the four....

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Yes and no. It was a common joke that the Hurricane could out-roll anything if you had Popeye at the controls. Spitfire pilots joked about "Hurri-lugging" because the Hurricane did require more effort to throw it round the sky, even if the Hurri could out-turn and out-roll the Spitfire. One reason was the British design of joystick, which had the whole length moving back and forwards for elevator control, but only the top third pivoted left and right for ailerons. This rather bizarre design idea was so the cockpit could be nice and slim and not require the pilot to move his legs when applying full bank. Aircraft like the P-36 had wider cockpits and the whole stick moving for the ailerons, which meant you had an advantage from better leverage, and it was easier for the average pilot to apply at higher speeds. Hence the P-36 and P-40 out-rolled the Hurricane and Spitfire in practice.

pinsog said:

….There is NOTHING an F4F-4 could do the shake a KI43.....

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The F4F-3/4 couldn't shake a Zero either, other than a turning dive, but they didn't need to. The Thach Weave was the successful use of better tactics, not a performance advantage, and it worked just as well against the Ki-43 as it did against the Zero, because it played on the Japanese pilot's willingness to get into a turning dogfight, allowing them to be drawn into a head-on with a second Wildcat. Even in 1945 the Thach Weave was still being used because the Japanese still couldn't resist following a Wildcat into a turning fight.

RCAFson said:

The above were Canadian built Hurricane X or XIIs.

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So no different to the Hurricane IIb/c used in Burma.

pinsog said:

I can't think of any ww2 fighter that could carry 500 pounds under each wing and still outfight another fighter

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These were unlikely to be 500Lb bombs. The depth bombs in use by Coastal Command at the time were typically 100Lb, with the heaviest being the 250Lb Mk VIII. IIRC, the Canadian Ansons used 112Lb depth and 250Lb GP bombs on anti-submarine patrols, so these Hurricanes were probably flying with 100Lb or 112Lb bombs.