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

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The early P-38 was not a good high altitude fighter:

P38 at high altitude
 
The IJ bombers were coming in well above 20k ft, and typically were at or above the Beaufighters service ceiling.
Your right. Some of the raids had Betty's coming in at 27,000-28,000 feet with the Zero's above them at 31,000 feet. I believe the early raids were much lower and they went higher to escape the P39's and P40's
 
The early P-38 was not a good high altitude fighter:

P38 at high altitude
I would agree that they had problems at high altitude over Europe. Long flights at low engine temps, freezing pilots etc. But Australia isn't cold like Europe and these would have been fast climbing interceptions up to the bombers altitude instead of flying 3-4 hours at minimal engine power. I've never read anything from the Pacific theater about the P38 except "we need more". Only negative thing I recall is just trying to keep them in flying condition which was hard to do with anything and I'm sure the complicated P38 was even worse.
 

As posted here Spitfires over Darwin error. the Merlin 46 MkV's we got were giving away 500hp over the standard 45 engined models. This discussion is going around in circles, the Spits we had were in poor mechanical condition, used ammunition from a brand new factory set up in western Sydney that was not within spec, we had poor leadership, no spares and of the almost 100 pilots of 1 wing, only 6 had previous combat experience.
 
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Please read the post again. The 500hp difference was at 11,000ft which from what most of the people posting are saying is not where the problem was. At altitudes over 20,000ft the Merlin 46 had around a 100hp advantage which means something else was problem (assuming factory spec engines) in combating the Japanese.

As for climbing to intercept altitude the 500 hp difference goes away or is reduced to under 100hp and more like 40-50hp. I doubt that the RAAF would have climbed from sea level to over 20,000ft using emergency boost. the 30 minute rating for both engines was 2850rpm and 9lbs boost.

If the RAAF was not using over 9lbs boost on the Merlin 46 would they have used over 9lbs boost on the Merlin 45?

The Merlin 45 simply cannot deliver more than 9lbs boost at altitudes over 17,400ft to 18,000ft with tropical filter regardless of what boost level is used at lower altitudes. and if fact down were under 5lbs at 23,000ft in max level speed and under 4lbs at best climb speed.

MK Vs using Merlin 45s and tropical filters over Darwin without any changes in tactics or other equipment (drop tanks?) would not have fared any better and quite possibly worse than the planes with the Merlin 46.

Use of 30 gallon slipper tanks would have meant taking off on internal fuel (I don't know if fuel could have transferred from the slipper/drop tank to the main tanks/s) and changing to the slipper tank at 500-1000ft and making the climb to 20,000ft and above on the slipper tank. This would have slowed the climb slightly. But the climb to just 20,000ft could use up 12-15 gallons of gas and the forming up of the big formation Cadwell favoured(?) could use up more
In any case a Spitfire V (non tropical) running at a cruise speed of 263mph at 20,000ft could burn as little as 36 gallons an hour so having an extra 20-30 gallons in the main tanks when the fight started at over 20,000ft meant that a lot fewer pilots and planes would have run out of fuel.
 

I don't think they had sent any VIII or IX to the Pacific in time for Darwin, though I could be wrong. They didn't get any Spit IX in the Med until a couple of months into 1943. VIII came later.

The Hurricane IIA was the other UK/Cdn fighter available in numbers but it's high altitude performance was somewhat less than the Spitfire V/M46 at ~310mph @30K ft.

Hurricanes had a fairly dismal record against A6M and Ki-43 type fighters, and also seemed to have trouble climbing in high temperature / Tropical environments. They even had trouble intercepting higher flying bombers at Malta which was arguably less hostile conditions than New Guinea, probably similar to Darwin. The problem may have been due to the infamous vokes filter. They could have field stripped them perhaps and / or come up with a different filter. They did develop a new one in the Med.

The P47 hadn't sorted out it's high altitude ignition problems in time for them to have been used. The P40F was marginal at best, because of it's climb rate and ceiling.

P-47 wasn't available later in '43.

Considering that the P-40E, with a 12,000' critical altitude, was used to some good effect in the defense of Darwin, it stands to reason that the P-40F with a 20,000' critical altitude might have been considerably more effective. Rate of climb was also dependent on load, it could range from as low as 1,700 fpm to as high as 3,300 fpm, depending on how heavy the aircraft was. Though of course that too is a tradeoff. Less fuel means quicker climb, more fuel means much longer endurance. Maybe you could combine the two- have one squadron kitted out for rapid interception and a second squadron kitted out for the sustained fight.

It's probably a cinch though that either way they could have taken out a pair of the wing machine guns and associated ammunition for work over Darwin, and as seen in the Med and shown in some side by side tests by the Aussies, in actual field conditions with four guns it would probably have a climb to 20,000 ft better than the Hurricane and definitely quite a bit better than the P-40E or P-39.

In the event though they only ever sent one or maybe two squadrons of P-40F to the Pacific and these went to the 49th FG, but I don't think this was until they had been redeployed in the Solomons.
 
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One other comment in defense of Caldwell. The "big formation" he favored was part of a series of hard learned lessons that the DAF had paid a bitter price to adopt as Tactics. To successfully face the Luftwaffe (and to be real - the more elite units of the Regia Aeronautica) the DAF pilots had learned to fly in large formations and to turn into attacks from above with guns blazing, and only when and if the Bf 109s or MC 202s chose to enter a sustained engagement would they break into flights of four and pairs.

In North Africa, flying in small formations was a death sentence, because both the German and Italian fighters usually had an altitude advantage (even against Spit Vs) and seemed to routinely attack from above, and they were also typically at least a little bit faster. If they caught small groups of Allied fighters they could pick them apart, but against larger groups acting in concert they often had to break off their attacks. In the desert there was safety in numbers.

It's worth pointing out that all of these Tactics were worked out at the squadron level and filtered their way up to become doctrine - often against fairly strong resistance. So that explains some of Caldwells stubbornness.

Given that the IJ fighters were still quite often attacking from an altitude advantage in Australia it was a reasonable assumption for him to make that they would still need to use such Tactics.

What he didn't realize until after facing combat with Japanese fighters, because it had not adequately been explained in Allied briefings by then, was that the main advantage for the Allied fighters including both the P-40 and the Spit V, was speed, especially in the dive. This affected tactics developed by the 49th FG in their defense of Darwin from March to September of 1942. 49th FG also had an experienced leader, in Lt. Col Paul Wirtsmith, and an experienced XO Major Donald Hutchinson - most of their pilots had very little experience, with 89 out of 102 pilots had no fighter training whatsoever. Training on type was similarly limited for the RAAF P-40 units as well.

49th FG developed tactics which were almost the opposite of Caldwells. Not all the IJ raids were at high altitude, but those that were posed a unique challenge. Unable to climb above the higher altitude IJ raids at 27-31,000', they had to attack from below, struggling with the P-40E's very anemic performance at that altitude, and would do so in pairs of 2 or flights of 4 aircraft, and immediately disengage by diving when attacked, then zoom climb to return to the fight. The advantage of the smaller groups of fighters was that they were able to keep up a steady stream of attacks against the bombers and thus undermined the effectiveness of the escorts - if they kept chasing P-40s another section would hone in on the bombers and starting scoring hits. This worked fairly well- they claimed 78 aircraft shot down for 19 losses, post war analysis shows the IJ forces actually lost 19 aircraft as well - 7 fighters, 12 bombers, and 1 recon plane, plus quite a few heavily damaged. The losses, particularly of bombers were too much for the Japanese and their raids tapered off for a while.

There is a good analysis of this period of fighting here

When Caldwell took over in 1943 he apparently discounted the American tactics as someone noted above, but after the first combat they seem to have shifted over to something more like them, with hit and run attacks and smaller sections.
 
Regarding fuel tanks and the P-47, when they first arrived to the 49th FG in New Guinea in July 1943 they had no external tanks, their range was so short they couldn't be used as escorts at all. Medium or light bomber strikes in the region were considered to require escorts for daytime strike missions, otherwise they got decimated. They started manufacturing 200 imperial gallon drop tanks in Australia which enabled the P-47s to start being used operationally by August of 43. However the P-47s apparently struggled to take off from the primitive airfields and just flying in general with these heavy tanks and there were a lot of crashes. As a result they were still using some P-40s and (to a lesser extent) P-39s (from the 35th FG) well into 1944.

They were able to fit the same 200 gallon Australian made drop tanks on the P-40s (with one per aircraft instead of two on P-47) for escorting raids to Lae, Rabaul etc., and against shipping such as during the Battle of the Bismarck Sea in March 1943. This increased P-40 combat range to 650 miles by mid 1943 allowing them to be used as escorts.

During this period No. 30 Sqn. RAAF was on site with Beaufighters (from Sept 42). They also had two heavy bombardment groups with B-17s and B-24s respectively, and two medium groups with B-25s and B-26 Marauders, but all of the bombers struggled with maintenance issues and the B-26s had to be withdrawn due to combat losses (later converted to B-24s). They also had some A-24s (SBD Dauntless Army version) which could be useful if they were adequately protected by fighters, but were very vulnerable if not.

P-38s were the preferred ride for the 49th, but were in limited numbers during much of 1943 because so many were being sent to the Med, and of course also had a lot of teething problems. They increasingly became more available & viable through 1943 and eventually took over as the main fighter for the 49th, with increasing cruise efficiency and so on after Lindbergh's visit in July 1944 gradually extending their range as well. By Sept 1944 the 49th FG was all P-38s.
 
One other thought that occurs to me is that the logistics chain of the drop tanks must have been fairly sigificant, if they are basically disposable (I guess if they go into combat they would be dropped, otherwise carried back) that means with the high rate of combat in 1942 and 43, probably something like 1.5 drop tanks per mission for a P-47 or P-38, or around .7 drop tanks per mission for a P-40 or P-39. That is quite a lot given how much trouble they had in New Guinea with even the most basic supplies. I wonder how often a shortage of drop tanks might have postponed missions or limited the number of aircraft.
 
The thought process of designing the p47 with such a limited range has always been a head scratcher for me. If ever there was a single engine fighter that had the power, room, and structural strength to tote a few more gallons of fuel without it affecting performance much it was the Thunderbolt.
 
They would only drop them when they made contact with the enemy. I can't imagine they got enough of anything they needed!
 

What people forget is that the P-47 had about twice the range of a Spitfire or 109 if none of them are carrying drop tanks.
It was good for around 700 miles at 15,000 at a bit over 260mph true using 265 gallons (allowing 40 gallons for starting warm up and take-off).
Now this turned out to be not enough range for what they wanted to use it for, or the theaters it had to fight in.

Lets remember that the USAAC agreed to order the Prototype XP-47B on Sept 6th 1940 when the daylight part of the BoB was still going on.
 
Verry true and I realize hindsight is 20/20 but by 1940 there was trouble brewing with Japan( they were already at war with China and from what I've read many saw the potential for conflict with the US) so seems like the need for more range would have been appearant and doesn't seem like youd loose alot of performance on a p47 by packing a little more fuel.
Maybe it just didn't look as obvious then as it looks now.
 

The design process for the P-47 was a pretty long and I suspect a fairly painful and desperate saga, especially if you take it back to the P-43 (which I don't think was actually ready for prime time so to speak even though a couple did make it to the field). It was obvious from early days that the design had great potential especially for high altitude combat. But the turbocharger, engine, cooling requirements and so on kept pushing the parameters so far that they ended up with a ridiculously large and heavy plane that they couldn't have helped but notice was decidedly an outlier in terms of design standards for a single-seat fighter.

In other words, they may have been so pre-occupied with the core design features, i.e. just getting it to function properly as a fighter, and trying to get it operational before the contract deadlines and so on (and with the benefit of hindsight - before the tipping point of the war had been fought through) that they hadn't had time to think of some of the (again in hindsight) obvious needs like external tanks.
 


To quote myself:


Now compare these figures with these:


http://darwinspitfires.com/index.php?page=performance-of-spitfire-vc-tropicalised-version-2

and we get a 43mph increase at 10k ft.
 
I agree the P43 wasn't combat at ready because of the leaky fuel tanks. But a few were used in china and they were also used as photo recon. I personally think if they would have had proper fuel tanks and a bit of pilot armor then they would have done well against the Japanese with boom and zoom tactics. Look up their performance and compare it to the first Hellcat and Spitfire Mark II and even the Spitfire Mark V at 25,000 feet. It would have done well at altitude and would have been good for flying top cover for P40's against Zero's. It is faster than a Zero at any altitude, getting to with about 10 mph at 17,000 feet but more like 40 mph at 25,000 feet
 
I agree the P-43 was a nice performer, but I think the armor and (self-sealing) fuel tanks are a bigger deal than you are calculating here. If you took the armor and self sealing tanks out of a Hurricane IIC or an F4F it would probably perform pretty well at high altitude too (maybe not quite as well but you know what I mean). The problem is the attrition risk to the pilot gets a lot higher.

Trust me, I'm a fan - I like the P-35 too (and I love the Re-2000 series which may or may not be related) but I don't think Seversky/Republic got it quite right and it wasn't until the P-47 that this initial design lineage really bore fruit. It's a shame they couldn't keep the clean lines of the original P-35 but those early turbos were not exactly petite.
 

Re-reading your thread on the Darwin MkV's, they should have been able to do 380-385mph between 16,000 and 24,000ft when fitted with the Merlin 46, instead they did 330mph at 20,000ft as per RAAF testing. How does a plane lose 50mph?.
 
 

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