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

[Schweik]

Its interesting to note that the RAF never thought any P-40 was good enough for service in Northern Europe. They kept their Hurricane IIs till mid 42 , after which they were replaced by Typhoons. In the DAF the Hurricanes were kept in front line service till the Spring of 43 after which they were replaced by Spitfires. In the Burma theater the Hurricanes excellent ground attack abilities and servicability kept in in front line service in large numbers till late 44, after which it was largely replaced by Thunderbolts.

P-40s weren't deemed suitable for defense of England due to their altitude limitation.

Hurricanes were actually replaced by P-40s in multiple squadrons in the Med, and by mid 42 almost all that were still flying were used as bombers. The only place they kept using them as fighters seems to be Burma.

In Russia Hurricanes were typically replaced by Yaks or P-39s.

 

[Schweik]

And all of this has exactly what relationship to the RAF campaign in Malaya, India and Burma?

Obviously the conversation is just an extension of the evaluation of the main British fighter in India and Burma - the Hurricane. It is central to the discussion that the Hurricane was arguably the most important fighter type in use by the British / Commonwealth forces in that Theater. The question being was it still suitable after 1942?

It's worth keeping in mind that the Soviets were also an enemy of the Japanese and did eventually engage them again in northern China / Manchuria in 1945. In fact you could make the argument that the real impetus for the Japanese surrender, even more than all the bombing including the A-bombs, was the precipitous collapse of their large and once very formidable Kwantung Army under the ferocious, highly efficient onslaught of the Red Army, including the rapid capture of Northern Korea and the Kuril islands by paratroopers and amphibious landings.

The Japanese authorities greatly feared a Soviet invasion as Imperial Japan was perhaps the most virulently anti-Communist polity on earth at that time. Being taken over by Stalin may have seemed to them a fate worse than death. Their armies on the mainland of China were their ace in the hole which they (unrealistically) hoped to somehow leverage against their enemies. In the early part of the war the IJA seemed to be nearly unstoppable.

When a large proportion of the IJA land forces in China were crushed decisively in less than two weeks all hope of revival of Imperial Japanese fortunes collapsed with them.

Air power was a major component of the combined-arms approach used by the Soviets in that invasion. The Japanese forces were largely obsolescent and in poor repair but they did have 1,800 aircraft in that part of the Theater on August 9 when the Soviet invasion started. No doubt the Japanese collapse saw the substantial use of Yak fighters with just a few nose guns

For the US the Theater was called the CBI - China, Burma, India. Prior to that decisive Soviet invasion, it's difficult to completely untangle USAAF and RAF efforts in that very broad region and the much more gradual successes of Anglo-American-Sino forces against the IJA, especially it's central focus for the Allies - the Burma Road, the main point of which was to supply and reinforce the Chinese army.

 

[Kevin J]

P-40s weren't deemed suitable for defense of England due to their altitude limitation.

Hurricanes were actually replaced by P-40s in multiple squadrons in the Med, and by mid 42 almost all that were still flying were used as bombers. The only place they kept using them as fighters seems to be Burma.

In Russia Hurricanes were typically replaced by Yaks or P-39s.

In Russia the Hurricanes were reassigned to the PVO, and operated as both interceptors and close escorts until 1944.

In the CBI, as fighters until finally replaced by Spitfires in 1944, but kept for ground attack until war's end. Outclassed with the arrival of the KI-43-II from 1943. All they needed was a Merlin 24 and a cleanup like the Sea Hurricane IIc and they would have been okay as fighters until 1944.

 

[Schweik]

PVO as I understand it was air defense over cities and other Strategic targets a long way from the front. The most vital PVO defenses were manned by Spitfire Mk IX and later, high altitude Yak 9 variants. Hurricanes, and later P-40s too, were assigned to defend the less critical PVO targets. It's worth noting that most of these were beyond the range of German day fighters so they were mostly just intercepting longer ranged bombers. So long as the bomber was slow enough, the Hurricane was still pretty good at that job.

In the CBI, as fighters until finally replaced by Spitfires in 1944, but kept for ground attack until war's end. Outclassed with the arrival of the KI-43-II from 1943. All they needed was a Merlin 24 and a cleanup like the Sea Hurricane IIc and they would have been okay as fighters until 1944.

Interesting proposition. Maybe true, but hard to prove.

 

[Schweik]

One other thing about Soviet Hurricanes worth keeping in mind, many of the ones that were sent to them (I don't know the exact percentage) had already seen combat and may have been 'clapped out' before the first Soviet pilot even flew them. This was true with some of the P-40s as well. They also had limited spares, no maintenance manuals and no winterization prep, and Soviet mechanics lacked familiarity with the much more demanding maintenance (including 'oil culture') standards for the engines in particular, causing endless headaches. All of this no doubt influenced the Soviet perception of the aircraft.

Lessons learned on the Hurricane and P-40 and other early adopted Western aircraft contributed to the careful workup that was done with the P-39.

 

[Schweik]

Did they ever replace the Vokes filters in Burma with more efficient types?

 

[Shortround6]

In the CBI, as fighters until finally replaced by Spitfires in 1944, but kept for ground attack until war's end. Outclassed with the arrival of the KI-43-II from 1943. All they needed was a Merlin 24 and a cleanup like the Sea Hurricane IIc and they would have been okay as fighters until 1944.

You do know that a Merlin 24 was functionally a Merlin XX with a modified supercharger drive that allowed 18lbs of boost to be used instead of 14lbs in low gear and 16.bs in high gear (heavier supercharger drive shaft?) and above around 12,500ft there was no difference in the power output of the two engines?
The supercharger itself was not changed and neither were the gear ratios which means the extra power is only available at relatively low altitudes. Merlin XX was good for 1485hp at 6000ft compared to the Merlin 24s 1635hp at 2250ft but the Merlin 24 would have dropped to about 1485hp at 6000ft.
The Merlin 24 was allowed to use 18lbs boost for take-off which would have helped with short airstrips and heavy loads but the utility of the Merlin 24 over the Merlin XX for air to air combat requires certain circumstances at a limited number of altitudes.

As to how useful the Hurricane II was as a fighter just compare it to the P-40F which used for all practical purposes the same engine. The P-40F was faster by 20-30mph and actually climbed better at around 20,000ft and up. It also carried more fuel (not much more) and carried about the same weight of guns and ammo (depend on how many .50 cal rounds).

The Hurricanes usefulness as a fighter rather depends on the Japanese NOT bringing in Ki-44s or K-61s to oppose it.

 

[Schweik]

The supercharger itself was not changed and neither were the gear ratios which means the extra power is only available at relatively low altitudes. Merlin XX was good for 1485hp at 6000ft

I was recently discussing a very similar topic with someone else on the forum, and wondered if you could provide some insight with your sources and knowledge about engines. First, do you know when these boost settings were approved for the Merlin XX, and second, were they ever approved for the P-40F/L?

All my sources lack any WEP setting for the V-1650-1 / Merlin 28 (which is nominally identical to the XX but there are no doubt some minor differences) and the highest power setting listed is the takeoff power of 1,300 hp at roughly 12 lbs boost / 54". I have 3 books which list this but none ever mention any WEP setting or any higher power setting.

I have seen brief mentions of 1480 or 1485 hp at +16 lbs boost, and I have seen pilot anecdotes in which they claimed or mentioned using up to 65" Hg boost in emergencies, but I have never seen that associated with any official document related to the Packard Merlin V-1650-1. Do you know of any?

 

[slaterat]

Hurricanes were actually replaced by P-40s in multiple squadrons in the Med, and by mid 42 almost all that were still flying were used as bombers. The only place they kept using them as fighters seems to be Burma.

I am not sure where this idea that P-40s replaced Hurricanes in North Africa came from but it is basically false. The only two Squadrons that ever replaced Hurricanes with P-40s in Africa were 250, that oddly replaced Tomahawks with Hurricane 1s, and then replaced the Hurricane 1s with Kittyhawks, and 260 which replaced Hurricane 1s with Kittyhawks. That's it, two squadrons replaced their old clapped out tropicalized Hurricane 1s with brand new Kittyhawks. It does not appear that any Hurricane 2s were ever replaced by P-40s.

The Hurricane Squadrons were still making claims from air to air kills till the end of the African campaign. 73 squad made 9 or 10 claims and an equal amount damaged in Tunisia in April and May 43. By this time the Kittyhawks were primarily fighter bombers as well.

 

[slaterat]

As to how useful the Hurricane II was as a fighter just compare it to the P-40F which used for all practical purposes the same engine. The P-40F was faster by 20-30mph and actually climbed better at around 20,000ft and up. It also carried more fuel (not much more) and carried about the same weight of guns and ammo (depend on how many .50 cal rounds).

RAF testing differs with you on the climb rate. The info I have is Hurricane 2, 8.8 mins to 20 k and 17 mins to 30 k. The Kityhawk 2 is 10.9 mins to 20k and 18.5 mins to 28 k. You can find better numbers for both but the Hurricane is always ahead on the climb. The speeds are fairly close when using the same boost. The Kitthawk 2 was not used in large numbers by the RAF as overall it really wasn't any better than a Hurricane. The Hurricanes handling and turn rate is far better as well.

 

[Schweik]

I am not sure where this idea that P-40s replaced Hurricanes in North Africa came from but it is basically false.

It's surprising that you keep making this statement because it's so easy to disprove. The last time you made this claim I replied with a detailed post which you seem to have somehow not seen, perhaps due to the magic of ideology. Here is a link to it from another thread and here is a repost for your convenience:

The following RAF / Commonwealth combat squadrons converted from Hurricanes to P-40s in the Western Desert (use of some types overlapped). It was a total of 7 combat squadrons in all:

From 239 Wing:

112 Sqn RAF (Hurricanes I in the first half of 41, Tomahawk in the second half, Kittyhawk I from Winter 41, Kittyhawk III in 1942, Kittyhawk IV in early 44, then Mustang III in late 44)
250 Sqn RAF (Hurricane I and IIB and IIC from February to April 42, Kittyhawk I and II April - October 42, Kittyhawk III from October 42, then Kittyhawk II again, then Kittyhawk IV in 44, and finally Mustang III from August 45)
260 Sqn RAF (Hurricane I and II from Nov 41 - Feb 42, Tomahawk II from Feb - Mar 42, Kittyhawk I from Feb - Sep 42, Kittyhawk IIA from Jun 42 - May 43, Kittyhawk III from Dec 43-Mar 44, Mustang III from Apr 44- Aug 45)
3 Sqn RAAF (Gladiators and Gauntlets - and a few Lysanders- in 1940, then Hurricanes in 1941, then Tomahawks in late 1941, then Kittyhawks from 1942- Nov 1944, then Mustang IV)
450 Sqn RAAF (Hurricane from May-Dec 41, Kittyhawk I and Ia from Dec 41 - Sept 42, Kittyhawk III from Sept 42 - Oct 43, Kittyhawk IV from Oct 43 - Aug 45, Mustang III from May 45-Aug 45)

from 223 Wing
4 Sqn SAAF (Hurricanes from March 41 - plus some Mohawks - Tomahawks from Sept 41, Kittyhawks from some time in 42, then Spitfires in July 43)
2 Sqn SAAF (Gladiator and Gladiator II from 1940, Hurricane in early 1941, Tomahawk IIB June 41 - May 42, Kittyhawk I Apr 42 - June 43, Kittyhawk III, June 43 - July 43, Spitfire VC from July 43 - march 44, Spitfire IX from Feb 44 - July 45)

As far as I can tell, one unit, 239 Squadron RAF operating as a recon unit from England switched from Lysanders (Sep 40 - Jan 42) to Tomahawk I and IIa (from Jun 41 to May 42) to Hurricane I and IIc (from Jan 42- because they didn't like the Tomahawk). Then they were converted to the Fairey Battle in Jun 42!!! Then the Miles Master in March 42, then finally to Mustang I in May 42, and Beaufighters in Oct 43 and then Mosquitoes from Dec 43.

I couldn't find any Western Desert units that switched from P-40 to Hurricane though I am not saying there weren't any. I just couldn't find it if there was.

5 Sqn SAAF never got Hurricanes to begin with (Mohawk Vk, Dec 41 with Tomahawk IIB, late 42 with Kittyhawk III, Kittyhawk IV in 1944)

In addition, some Canadian squadrons which seem to have been home-defense units based on Canada's Pacific coast, converted from Hurricanes to Kitythawks, but I don't consider these combat units. They included:

133 Squadron British Columbia (converted from Hurricanes to Kittyhawks in March 44, then to Mosquitoes)
135 Squadron Patricia Bay (converted from Hurricanes to Kittyhawks in May 44)
163 Squadron Sea Island (converted from Hurricanes to Kittyhawks in Oct 43)

Please note that in fact 250 RAF did convert from Hurricane IIB to Kittyhawk, as did 260, and I think 3 RAAF as well.

The Hurricane Squadrons were still making claims from air to air kills till the end of the African campaign. 73 squad made 9 or 10 claims and an equal amount damaged in Tunisia in April and May 43. By this time the Kittyhawks were primarily fighter bombers as well.

Yes, they still made a handful of claims in 1942 and 1943 while flying fighter bomber missions, but compare the above to the claims for any of the US fighter P-40 groups or to the 239 Wing or 223 Wing RAF / Commonwealth groups. Kittyhawk II and IIIs and P-40F/L were flying escort missions routinely in April and May 1943, quite often for Hurricanes or older model Kittyhawks.

We can debate this further in that other thread if you want to rather than continue to derail this one.

 

[Kevin J]

You do know that a Merlin 24 was functionally a Merlin XX with a modified supercharger drive that allowed 18lbs of boost to be used instead of 14lbs in low gear and 16.bs in high gear (heavier supercharger drive shaft?) and above around 12,500ft there was no difference in the power output of the two engines?
The supercharger itself was not changed and neither were the gear ratios which means the extra power is only available at relatively low altitudes. Merlin XX was good for 1485hp at 6000ft compared to the Merlin 24s 1635hp at 2250ft but the Merlin 24 would have dropped to about 1485hp at 6000ft.
The Merlin 24 was allowed to use 18lbs boost for take-off which would have helped with short airstrips and heavy loads but the utility of the Merlin 24 over the Merlin XX for air to air combat requires certain circumstances at a limited number of altitudes.

As to how useful the Hurricane II was as a fighter just compare it to the P-40F which used for all practical purposes the same engine. The P-40F was faster by 20-30mph and actually climbed better at around 20,000ft and up. It also carried more fuel (not much more) and carried about the same weight of guns and ammo (depend on how many .50 cal rounds).

The Hurricanes usefulness as a fighter rather depends on the Japanese NOT bringing in Ki-44s or K-61s to oppose it.

Agreed, but you should be able to get an extra 13 mph at altitude if you do the same mods as the Sea Hurricane IIc which would be useful against the Ki-43-II.

 

[Kevin J]

Did they ever replace the Vokes filters in Burma with more efficient types?

Not that I know.

 

[Kevin J]

Not that I know.

Ideally we need those Spitfire Vb Trops for Russia with the Merlin 46 in early 43 in India. I guess there was some politics involved in their final destination. Alternately, a cleaned up Hurricane IIc with a less drag inducing filter maybe Merlin 24 so that we have it doing 322 at 13000 and 342 at 22000 so being more competitive against the Ki-43-II.

 

[Schweik]

I think the only real problem with the Hurricane was the lack of an escape maneuver. Other Anglo-American planes used dive - the Hurri had those big wings. It didn't seem to be able to dive out of trouble.

I agree though that there was clearly a speed (in level flight) threshold involved. So long as the Hurri was in the ballpark on speed or had a slight edge as in Burma in the earlier days, it's pilots had something to work with, once it fell behind a little (beyond a certain point) or lost that edge it lost the initiative.

 

[Kevin J]

I think the only real problem with the Hurricane was the lack of an escape maneuver. Other Anglo-American planes used dive - the Hurri had those big wings. It didn't seem to be able to dive out of trouble.

I agree though that there was clearly a speed (in level flight) threshold involved. So long as the Hurri was in the ballpark on speed or had a slight edge as in Burma in the earlier days, it's pilots had something to work with, once it fell behind a little (beyond a certain point) or lost that edge it lost the initiative.

Supposedly it could do 450 in a dive so more than a Ki-43. A Merlin 24 would give it a good low altitude performance edge. So exit manouvre would be dive then boost to run then zoom climb back. That should be okay until the Ki-43-III comes along and it's outclassed. You could then remove 2 cannon to improve the roll rate. Now that they did.

 

[Schweik]

They did that (removed two guns) in Russia and in the Med at least some times. Do you have records of diving as escape maneuver with Hurricanes in the CBI?

 

[Shortround6]

I was recently discussing a very similar topic with someone else on the forum, and wondered if you could provide some insight with your sources and knowledge about engines. First, do you know when these boost settings were approved for the Merlin XX, and second, were they ever approved for the P-40F/L?

All my sources lack any WEP setting for the V-1650-1 / Merlin 28 (which is nominally identical to the XX but there are no doubt some minor differences) and the highest power setting listed is the takeoff power of 1,300 hp at roughly 12 lbs boost / 54". I have 3 books which list this but none ever mention any WEP setting or any higher power setting.

I have seen brief mentions of 1480 or 1485 hp at +16 lbs boost, and I have seen pilot anecdotes in which they claimed or mentioned using up to 65" Hg boost in emergencies, but I have never seen that associated with any official document related to the Packard Merlin V-1650-1. Do you know of any?

The Manual for the P-40F and L, revised June 20th 1943 says that 61 in could be used for WER in both high and low gear, Low gear used below 8000ft and high gear above 8000ft.
61in works out to just about 15 1/2lbs boost so take it for what you think it is worth. It is on page 2.

However the engine chart on page 37 just shows 1300hp at 4800ft for 61in inlow gear and 1300hp at 13,000ft for 61in. in high gear which is rather strange (wrong?) .
same chart says 1240hp at 11,500ft using 48in (9lbs) military power in low gear.

1300hp for take-off using 54.3in (12lbs boost) is on the chart.
Sloppy editing? copied the 1300 figure into boxes it wasn't supposed to be?
I don't think any US engines got a WER until fall of 1942 (at least an official one) which means early copies of pilots manuals are not going to list it.

 

[Schweik]

Thanks Shortround6 much appreciated.

It's quite possible it was a mistake that just got repeated over and over from the manual. 61" should mean much more than 1300 hp below say 2,000 feet.

Certainly by June 43 they would have been using the higher boost settings.

 

[Shortround6]

RAF testing differs with you on the climb rate. The info I have is Hurricane 2, 8.8 mins to 20 k and 17 mins to 30 k. The Kityhawk 2 is 10.9 mins to 20k and 18.5 mins to 28 k. You can find better numbers for both but the Hurricane is always ahead on the climb. The speeds are fairly close when using the same boost. The Kitthawk 2 was not used in large numbers by the RAF as overall it really wasn't any better than a Hurricane. The Hurricanes handling and turn rate is far better as well.

Thank you, Speed for one KittyHawk 2 was 354mph at 48in and that was with both fittings for under fuselage bomb/drop tank and slots in the wings for under wing bombs.

http://www.wwiiaircraftperformance.org/P-40/FL220.pdf

Plane is at 8910lbs (?) granted planes varied in weight but that seems a bit heavy. Weight and loading chart calls for 8860lbs with full internal fuel, full oil, 506lbs of .50 cal ammo (281 rog) and 27lbs of extra radios.