An Allison V-1710 with a two-speed supercharger in 1942 (3 Viewers)

[tomo pauk]

The Defiant is somewhat maligned for not being a Spitfire. However, as a two-seat aircraft with a heavy power-operated turret, it performed well in its designed function.
Unfortunately, the whole concept of Turret armament continued to plague "bomber fighters", and particularly RAF Doctrine.

If it was just a Hurricane from another mother...
But yes, company made what was required from them and what they have gotten paid for. It was the turret fighter idea that was badly wrong, and come in the very wrong time.

The real decisions about British Aircraft production lay with the Government Minister, the Ministry's and The Leaders of the RAF. A total attack on the production orders of the time would require an immense amount of work and would probably still not reveal all the details and subterfuge!

All true.
The production of a different aircraft does not happen by the flick of the switch, but a much degree of urgency towards having both better and more Spitfires in 1941-43 would've been great IMO. Everyone in UK that mattered knew in 1940 that, among the British fighters, Spitfire was an over-achiever.

 

[Engineman]

There are the interesting contemporary illustrations on the Luftwaffe equipment in the BoB. The Stuka was a very accurate dive-bomber. Somewhat rugged it was slow and it was shot to bits in attacks on the UK CH radar sites. Unfortunately for them, those attacks were of low effect and they were not repeated. If the Germans had realised the value of the CH radar, they should have prioritised its destruction, despite the Stuka losses. IMO, the Stuka could have completely changed the outcome of the BoB, if British radar was knocked out early-on.

The Bf 110 was a much touted Destroyer. A very good twin-engined heavy fighter, it was only a little less fast and agile than the Spitfire and Bf 109 in the Battle, plus it had extra range. However, it was shot to pieces in the battle, so much so, that it was withdrawn. But the Bf 110 was a good aircraft and it went on to be a dependable aircraft in slightly less defended areas. Also, it proved to be probably the highest scoring night-fighter type of the War, again operating in a less risky environment.

These examples (and the Defiant) show that the dominant Fighter equipment will totally overcome even the slightly less effective types, if available in effective numbers and employed in effective ways.

Eng

 

[MikeMeech]

The Defiant is somewhat maligned for not being a Spitfire. However, as a two-seat aircraft with a heavy power-operated turret, it performed well in its designed function.
Unfortunately, the whole concept of Turret armament continued to plague "bomber fighters", and particularly RAF Doctrine. It seems that the Official realisation of the vulnerability of the Defiant was not realised until the early stages of the BoB. By that time, the chances of BP changing their Defiant production to anything else in short order were non-existent. That said, Defiants did do some useful work in the learning days of British AI radar, and with specialised ECM, possibly quite efficiently, flying with just one early Merlin.
The real decisions about British Aircraft production lay with the Government Minister, the Ministry's and The Leaders of the RAF. A total attack on the production orders of the time would require an immense amount of work and would probably still not reveal all the details and subterfuge!

Eng

Hi
It is not difficult to trace the decisions on British aircraft design and production, here are just a few of the sources as examples:

Mike

 

[tomo pauk]

There are the interesting contemporary illustrations on the Luftwaffe equipment in the BoB. The Stuka was a very accurate dive-bomber. Somewhat rugged it was slow and it was shot to bits in attacks on the UK CH radar sites. Unfortunately for them, those attacks were of low effect and they were not repeated. If the Germans had realised the value of the CH radar, they should have prioritised its destruction, despite the Stuka losses. IMO, the Stuka could have completely changed the outcome of the BoB, if British radar was knocked out early-on.

The Bf 110 was a much touted Destroyer. A very good twin-engined heavy fighter, it was only a little less fast and agile than the Spitfire and Bf 109 in the Battle, plus it had extra range. However, it was shot to pieces in the battle, so much so, that it was withdrawn. But the Bf 110 was a good aircraft and it went on to be a dependable aircraft in slightly less defended areas. Also, it proved to be probably the highest scoring night-fighter type of the War, again operating in a less risky environment.

We can recall that both Ju 87 and Bf 110 were still produced and used in combat en masse and on daily bases, both before BoB and years after the BoB. Bf 110 was very useful in providing the cover as far as Norway in 1940 and later in the Med and Russia, also used as a fighter-bomber, and Ju 87 was instrumental in the Blitzkrieg victories.

Defiant's combat record was but a footnote in ww2 air war.

These examples (and the Defiant) show that the dominant Fighter equipment will totally overcome even the slightly less effective types, if available in effective numbers and employed in effective ways.

Categorizing the Defiant among the 'slightly less effective types' when talking about the fighters requires the truckload of salt to digest.
Even the biplane Gladiator was a better fighter.

 

[PAT303]

Conversely, I have tried to point out that IT WASN'T IMORTANT ENOUGH TO EITHER THE RAF or Ministry of Production to implement major changes to increase range.

Lots of slipper tanks, drop tanks and aux tanks were developed for the Spitfire/Seafire.

Quote
The Mk XVI was the same as the Mk IX in nearly all respects except for the engine, a Merlin 266. The Merlin 266 was the Merlin 66 and was built under licence in the USA by the Packard Motor Company. The "2" was added as a prefix in order to avoid confusion with the engines, as they required different tooling. All Mk XVI aircraft produced were of the Low-Altitude Fighter (LF) variety. This was not determined by the length of the wings (clipped wings were fitted to most LF Spitfires), but by the engine, which had been optimized for low-altitude operation. All production Mk XVIs had clipped wings for low altitude work and were fitted with the rear fuselage fuel tanks with a combined capacity of 75 gal. Many XVIs featured cut-down rear fuselages with bubble canopies. On these aircraft the rear fuselage tank capacity was limited to 66 gal. Because of a slightly taller inter cooler and rearranged accessories on the Packard Merlins a new, bulged upper cowling was introduced and also appeared on late production IXs. Armament for most Mk XVIs consisted of 2 × 20 mm Hispano II cannon – each with 120 rpg – and 2 × .50 caliber Browning machine guns – each with 250 rpg. 1 × 500 lb (227 kg) bomb could be carried underneath the center rack, and 1 × 250 lb (114 kg) bomb could be slung under each wing.

 

[PAT303]

Hi
Actually all rather earlier than Sept. 1941 with development starting before May 1940, see image below from Morgan and Shacklady:
View attachment 879838
Some other images from Green & Swanborough 'RAF Fighters part 3' page 16:
View attachment 879839
Actually used on Operation 'Sunrise' on 24 July 1941, from 'Fighter Command War Diaries Volume 2' by John Foreman:
View attachment 879840
I hope that is of interest.
Mike

I don't know ho they could have looked at that ''thing'' and thought yeah that's the way to do it.

 

[Shortround6]

That said, Defiants did do some useful work in the learning days of British AI radar, and with specialised ECM, possibly quite efficiently, flying with just one early Merlin.

It is this 'white washing' of the Defiant that I find objectionable.
The H-P Heyford did some work as both a radar target in early experiments and a part of an airborne radar system. Transmitter was on the ground, the receiver was in the aircraft with the antennae was strung between the landing gear.
Doesn't mean they should have restarted Heyford production
Operational Defiants didn't get radar until fall of 1941, over 1 year after the Blenhiems and just under 1 year after the Beaufighters went into service with it. Yes they made up a large part of the British nightfighters in the winter of 1941/42. Now we have to ask is if they should have. Actual kills by Defiant IIs with radar in the fall/winter of 1941/42 were..............one? I have no idea of the operational losses. Claim to fame is that showed how to fit radar into a single engine aircraft?
Yes, the Defiants were used for ECM. They had them, they used them, the ECM gear worked. Would the ECM gear have worked in other airframes?
The Defiant airframes worked, that is not the problem, the problem is the concept was a failure and it was adopted without adequate testing of the concept.
British were trying to solve a problem with air to air gunnery that didn't exist.

 

[Engineman]

Hi
It is not difficult to trace the decisions on British aircraft design and production, here are just a few of the sources as examples:
View attachment 880039
View attachment 880040

View attachment 880041
View attachment 880042
View attachment 880043
View attachment 880044
View attachment 880045
View attachment 880046
Mike

Yes, some interesting material. However, if you have a working knowledge of all those examples, can you say why the Turret fighter was supported so strongly in spite of its obvious severe compromises?

Eng

 

[Shortround6]

The British built 42% more Defiant's than they did Gladiators. The Gladiators shot down more enemy aircraft. Granted the Defiants showed up later and fought against a bit tougher enemy. Return on investment was very low as fighters.
Return on investment as target tugs is also somewhat questionable although better.
British wound up building over 1700 Miles Martinet target tugs new but only starting in 1942.
Not as fast as the Defiants but lower cost and faster than the hundreds of Lysander tugs using the same engines.
The Martinets were adapted from the Miles Master design and were built as tugs in the factory, not adaptations/conversions of existing aircraft.

 

[Geoffrey Sinclair]

Think about the results from search engines. British production figures have a margin of error in them thanks to the way they were compiled, Spitfire V/IX figures run into the mid 1942 actions of V being flown from factory to Rolls-Royce, becoming IX then delivered.

Some production numbers here (just googling, so correct me if I'm wrong)

Hurricane Mk II production: 8,600 (451 Mk IIA, 2,948 Mk IIB, 4,711 Mk IIC, 296 Mk IID, 270 Mk IV)

How does IV = II? Most likely the mythical IIE, often seen in air displays alongside dragons for appreciative audiences of unicorns.

When the RAF fitted a power operated gun turret to the Overstrand (top speed 153 mph) it noted a 5 fold increase in gunner accuracy, as a result the RAF was confident its new generation monoplane bombers could fight their way through fighter defences.

Memories of the WWI Bristol Fighter created a view towards the two seater, the Defiant upgraded this with a turret as an unescorted bomber destroyer, to become a fighter required understanding the Bristol Fighter had forward firing armament *supplemented* by the gunner who also acted as another pair of eyes.

Defiant, 87 ordered in 1937, prototype first flight 31 August 1937, another 363 ordered in 1938, 800 more in 1939 which would be after war was declared following the dictum only what is in production can go into mass production, of these 330 later cancelled (in 1942?), 150 ordered as target tow in 1941, 10 of these cancelled. Defiant fighter production ended in May 1942, changing over to target tug, the final one of which built in March 1943.

With the near instant need for a night fighter force the Defiant filled the gap until the Beaufighter and Mosquito became available in the required numbers. It made more Hurricanes and Spitfires available for the day defences and having a second pair of eyes made it more effective in the stop gap night fighter role. Later the Germans fitted upward firing guns to their night fighters. How good it might have been when radar equipped or cat's eyes in summer is unknown as the Luftwaffe withdrew the target. Seems the modifications to add radar made it suitable for ECM work. The Defiant was misused during the day battles, rather like the Bf110 which often gets tagged as a failure (after all it was the long range escort as designed) despite successful service afterwards.

Miles Martinet production began in August 1942, ending in May 1945, Queen Martinet built April 1945 to August 1946. Queen Bee production off and on 1935 to 1944.

P-47 Thunderbolt (1942-43): ~3,000 (includes 171 B and 602 C which I don't think were combat ready)

As of 19 September 1943 the 8th Air Force P-47 groups still held 116 P-47C along side 302 D models, it was the C that entered combat, P-47 production 1942/32 was 4,960.

F4U production in 1943: ~ 1,200 (not sure how many of these were really combat ready types)

F4U were considered combat worthy from the start but not carrier worthy, 2,293 accepted in 1943.

Losses -
Luftwaffe losses in North Africa 1942-43: ~3,000 (600-700 aircraft in action or accidents, 2,400 counting aircraft left on airfields etc.)
Regia Aeronautica North Africa aircraft losses 1942-43: 400-500 aircraft + unknown (or i couldn't find data) for left behind / lost on the ground
Luftwaffe + Regia losses Sicily campaign 1943: 2,011 (320 (225 German and 95 Italian) in action or operational, 1,691 lost due to captured airfields etc.)

The MTO USAAF fighters alone claimed 1,351 enemy destroyed in the air in 1942/43, versus maybe 1,500 all cause losses according to the above, remove at least a third for accidents, then bombed on ground, AA, the RAF and other USAAF types contribution. The P-40 was clearly not very good given how much over claiming it must have been doing. Meantime the Luftwaffe quartermaster was really working for the allies and 8th Army can claim to be the most successful "Fighter Group" on the allied side. Plenty of axis aircraft left behind, how many were repairable is another matter, write offs, cannibalised airframes or ones staked out as targets do not count.

USAAF losses North Africa ~1,800 aircraft

AIR 22/401 Assuming North Africa means to end April 1943, USAAF out of Egypt 97 aircraft, NW Africa 667 aircraft lost

Combined Allied aircraft losses Sicily ~200-300 aircraft (including 140 US)

July and August 1943, RAF Desert force 40 aircraft, Malta 68 plus 1 US, NW Africa RAF 172 aircraft (1 French), USAAF 305 aircraft.

US aircraft losses CBI (through 1945): ~600-700 aircraft

The USAAF Statistical Digest gives two figures which both probably exclude the China airlift losses. Table 100 says CBI combat and accident losses were 3,289 first and second line aircraft, table 163 says losses on combat missions were 1,076.

Comments:

• I could not find the total number of Luftwaffe losses in fighting over the channel in 1942-43,

Until channel is defined no one knows, presumably the losses taking on the 8th AF over Germany do not count, even if they came from Luftflotte 3?

• Just taking a wild guess here, but I would bet a beer that about 5,000 of those 8,000 Hurricane Mk II were 'extra', as were about 3,000 of the Spitfire Mk V.

All 4 Hurricane lines shut down in March 1942, all 3 Spitfire V lines in May.

• If we can assume that something better in terms of performance and range could have been possible in time to be fielded in 1942-43. If not I'd say swap Hurricane production for Spitfire as we already discussed.

Rather it can be noted despite all the objections to the idea of one type in and another out the idea will be repeated, magnanimously waving away problems.

• The reason being that both Hurricane and Spit V were extremely limited in both range and endurance. This was a big problem for both in North Africa, and in Burma and India, and for the Spit V in Australia. It basically prevented it's active use in the South Pacific Island campaigns which could have been a very helpful contribution.

Again what targets were regularly outside Spitfire V range in North Africa? The Australians received more than the number of Spitfires needed for the commitment to defend Darwin, since you must have read the online history of 79 RAAF squadron what does basically prevented mean? Darwin to Timor is over 400 miles, requiring a similar combat radius.

The RAAF history devotes around 3 pages to the 2 May 1943 combat over Darwin. In the actual air combat the allied pilots claimed 6 kills and, by the end of the fighting, had lost 5 aircraft. A further 5 aircraft force landed due to lack of fuel, 1 a write off, 3 others had engine failure and 1 of these was a write off. So all up 8 Spitfires lost.

Also the history notes the Spitfires were told not to dogfight the Zeros, and bounced the fighters from above, but, as it turned out, in too steep a dive, 70 degrees from 10,000 feet higher. Which shows the instructions to avoid a turning fight and a lack of practice in the tactic. The 10,000 feet extra height was due to the fact the bombers attacked from around 27,000 feet with the escort as much as 4,000 feet higher feet then began a steady dive away while the Spitfires had climbed to 32,000 feet to be above the escorts.

The Spitfires arrived in Darwin in January 1943, first combat on 6 February. The first big fight, against an estimated 45 Japanese aircraft saw the allied pilots claimed 7 kills for 4 Spitfires lost. As of the start of the deployment, there were 6 fully experienced pilots and 37 who had some fighter combat experience, out of the 95 pilots.

All from Air War Against Japan, 1943-1945 by George Odgers, Canberra, Australian War Memorial, 1957.

• I will also guess that 4,000 of the 8,000 Airacobras produced could have been skipped. The ones that were built should have been sent to the Soviets.

P-39 line shut in March 1943.

• Probably half of the P-40E, K, M and N could have been better replaced by F/L types. The F/L was viable in the MTO through early 1944 and would have been useful in the South Pacific and China / Burma / India through the end of the war.

General Kenny preferred the P-38 to the P-47, also in a supply constrained position (B-26 and B-17 removed to ease things), having an all Allison fighter force had appeal. Merlin meant dealing with the RAAF and RNZAF for the support facilities.

• There was a shortage of the best US and British fighter aircraft through the end of 1943 - especially the Spitfire Mk VIII, P-38, F4U, and P-40F/L.

Given the P-47 and in particular the reported low axis losses in the air in the MTO the P-40F/L does not qualify for "best"

• I was quite surprised by the large number of F6F produced (if that number is correct) but if it is correct, it seems like more of these could have been deployed by the USN sooner

Grumman managed to turn out 10 F6F in 1942, then 12 in January 1943, rising to 458 in December, the final quarter figures really making the yearly ones look good. Things like the laws of production to mass production, remaining F4F production and the need for TBF meant trade offs over what to produce during 1943. Also RN carrier practice was significantly behind USN, making allocation to the RN less efficient, first allocations in March 1943. Meantime in the Pacific for most of 1943 the carriers and battleships on both sides became quite shy, the USN added 7 Essex and 9 Independence class December 1942 to December 1943. Each requiring an air group plus reserves.

I do think that the Luftwaffe Fighter performance actually changed a lot from early 1942 to Q4/44.

To clarify I was thinking day fighters and the sorts of things that kept you out of enemy fighter gun sights, speed, roll, climb etc. And yes it is an opinion on how much change makes for improvement. The night fighter force had a big upgrade starting in early 1944 as the Ju88G arrived.

Very broad-brush, the German fighters had many problems with engines in mid 1942.

Yes, which meant degradation in performance over the Bf109F-4 and early Fw190A as weights were being added on the assumption the extra power was available, how much is not something I have seen measured.

Late Spring 1944 saw the introduction of the DB 605 AS high altitude engine into variations of the High Altitude Bf 109

The reports are, like the 1942/43 engines, trouble with the new supercharger meant performance was not delivered reliably.

and by June 1944, the general introduction of MW50 power boosting made big improvements of the low/middle power ratings of many German Aero-engines.

Agreed but again in broad brush terms it was not that great an improvement, unlike the Bf109G-10 and K and the Fw190D-9. Or the Bf109F-4 versus the E or Fw190A versus the Bf109E or early F. Opinion of course.

 

[Steamed_Banana]

"Geoffrey", I will once again advise you to keep your long-winded, gibberish posts directed at other forum users than myself, you and I are never going to have a production discussion about anything online. Or are you just trying to derail this thread by turning it into a flame war? None of your trollish questions are sincere, and most of your claims of alleged facts are clearly baseless and demonstrably false.

The Darwin Spitfire losses (about which I made no specific claims, it's worth noting) have been debated many times, including here on this forum, for example here and here. If you read these threads, you'll see that the details remain contentious. You'll notice that "Geoffrey"'s numbers for losses are well below all of the sources in those threads, such as those from Darwin Spitfires. Draw your own conclusions

 

[Howard Gibson]

Although the "official" BoB finished in October 1940, the night Blitz continued until May 1941. Later heavy bombing continued with the Baedecker Blitz and operation Steinbock.

Eng

Nightfighting was not the responsibility of Spitfires. Bristol Beaufighters and Mosquitos got the job done. The Germans continued limited bombing of Great Britain, with heavy losses. Intensive daylight bombing would have been suicide.

 

[Shortround6]

Think about the results from search engines. British production figures have a margin of error in them thanks to the way they were compiled, Spitfire V/IX figures run into the mid 1942 actions of V being flown from factory to Rolls-Royce, becoming IX then delivered........................................

Mostly I agree with you. Some corrections follow.

Memories of the WWI Bristol Fighter created a view towards the two seater, the Defiant upgraded this with a turret as an unescorted bomber destroyer, to become a fighter required understanding the Bristol Fighter had forward firing armament *supplemented* by the gunner who also acted as another pair of eyes.

Yes the British had very fond memories of the Bristol fighter. Bristol fighters also did fairly will with the forward firing MG.
Hawker Demon was an aberration. In the sense that Hawker Hart light bomber could outrun most or all of the British single seat fighters and they needed something faster in a hurry.
So they built a Hart to catch a Hart (just gave a Hart bomber a bit better gun installation) and called it a two seat fighter and then bureaucracy reared it's head. Once they had 2 seat fighters in inventory bureaucracy said they had to come up with a replacement two seat fighter. Once they had them they would figure out what to do with them

Miles Martinet production began in August 1942, ending in May 1945,

This is very true. While the Martinet was different than the Master (reinforced airframe for target towing, engine moved forward for better CG to balance the equipment and towed target, better cooling, raised canopy for better vision) there was no technical reason they could not have been built earlier except for the need for actual trainers. Mercury engines were not really high tech.

F4U were considered combat worthy from the start but not carrier worthy, 2,293 accepted in 1943.

Some argument on this. At least 1 USN squadron deck qualified with the F4U in summer of 1943 but the USN decided to standardize on the F6F for carriers for logistics. people can and will argue about this. I will only note that F4U-2 night fighters are used in small numbers on board carriers starting in Jan 1944. Selected pilots? When the Corsair it later (April 1944) deck qualified it is done with an escort carrier, the Gambier Bay (19kts and 474f t flight deck).

All 4 Hurricane lines shut down in March 1942

I don't know about Canada, Hawker kept producing until 1944 in smaller numbers. Austin and Gloster both stopped in March 1942

P-39 line shut in March 1943.

P-39 production ended in Aug 1944 with 12 planes. This tapered down from the 351/350 in Jan/Feb. July and Aug 1943 had seen 503 and 501 aircraft built but Bell was changing over the P-63. Production of the P-63 was slow to ramp up as the engine (V-1710-93) did not pass certification until Oct/Nov. Planes built before then were flown under restrictions.

 

[Steamed_Banana]

Regarding the Bf 110 vs Defiant comparison,

Though successful initially, Bf 110 failed in it's originally intended combat job as a day-time, medium-range escort fighter. It was successful in this role for the first few major campaigns in WW2 (Poland, France, Yugoslavia, Greece, Russia) but failed in the Battle of Britain. It was then repurposed and found very high to moderate success in at least four other roles:

• Night fighter (VERY successful in this role as we know, to the end of the war)
• Fighter -bomber
• Heavy bomber destroyer
• Maritime patrol / long range fighter (e.g. dueling with Beaufighters in the Med)

The Defiant failed in it's initial job as a day-time short range interceptor or fighter. It was then repurposed as a night fighter, in which role it also clearly failed. Then it was given a non-combat role as a target tug, in which it may have performed 'sterling service' but to suggest that the design was a success in any way comparable to the Bf 110, let alone any successful day fighter, or that it was more useful as a day fighter than any mark Spitfire was to the overall war-effort, is clearly a stretch.

As an aircraft design, the Defiant doesn't seem so bad. Comparable to the early Hurricane in performance, at least. But the turret fighter idea was obviously a bad idea.

This was by no means unique to the British. US considered this as a concept:

 

[Shortround6]

Nightfighting was not the responsibility of Spitfires. Bristol Beaufighters and Mosquitos got the job done. The Germans continued limited bombing of Great Britain, with heavy losses. Intensive daylight bombing would have been suicide.

This is very condensed. The night part of the BoB was like somebody flipped a switch in April and May of 1941.
Now the Spitfire and Hurricane had been specified as "night fighters" when ordered, some of them were equipped as "night fighters"
But the modifications were scant.

This is a IIC but some MK Is had the same modifications. Black paint, Glare shield on fuselage to exhaust glow did not blind pilot, a pair of flares in tubes behind the cockpit to aid landing (helped pilot actually see the runway he was trying to land on) and the ever-popular landing light
Success was minimal, danger and losses were high.
Hurricanes were preferred although some Spitfires can be found with the glare shields.
Actual nightfighter success in the BoB was close to the following.
8 German losses in in the first two months out of 12,000 sorties.
Much worse in the next 3 months.
March 1941 sees 22 German losses (most due to Beaufighters)
April sees 48 German losses.
First 2 weeks in May sees 96 German losses.
Note that the change in amount of light (hours of darkness) and weather may have had some influence on the change in losses as did the growing experience the AI IV radar. May 1941 was the High point of the Defiants night fighting career. They may have scored just under 25% of the German losses. The Beaufighters were doing most of the work.
The Idea of using Spitfires as night fighters had gone away. They had a higher accident rate than Hurricanes flying the same missions and both had a miserable success rate.

 

[Howard Gibson]

Institutional inertia, shortsightedness and turf war were a thing. So were the wrong purchases and pet ponies (hence we have two - two - factories making the Bothas, and the turret fighter made in 1000+ copies, so was the biplane fighter made in many hundreds in the late 1930s). Nobody have had monopoly on these shortcoming, not the Japanese, not the British, not the Germans.

Spitfire needed minor changes to increase the range. What was not there was the doctrine to call for that.


Stop noticing

I am looking for scale drawings of Spitifire_VIIIs and P51Bs. I want to draw a layout showing exactly where the gas tanks are. Spitfires and Mustangs are not laid out the same.

The Spitfire's primary gas tanks are located at the centre of mass of the aircraft. This is an optimal location from the point of few of aircraft trim, although it is not very good for the pilot if it catches fire. The Mustang's tanks are in the wing roots. Compared to a Spitfire, a Mustang pilot sits very much further forward, on top of the wing. A Spitfire pilot is lined up with the trailing edge of the wing. On the Spitfire_VIII and the subsequent XIVs, there is an 11 imperial gallon tank in each wing, in front of the wheels. This is still close to the fore and aft centre of mass.

On the P51D and the Spitfire_XVIII, additional fuel tanks were mounted in the fuselage behind the pilot. The Mustang's 75 US gallon rear tank affected the trim of the aircraft to the point of creating flying hazards. Spitfire_XVIIIs missed the war. Their smaller 33 Imperial gallon tank was located further to the rear, for the reason noted above, which is bad for aircraft trim. I am not aware of them flying risky long range missions. The bigger, heavier engine at the front might have helped things.

 

[Steamed_Banana]

P-39 production ended in Aug 1944 with 12 planes. This tapered down from the 351/350 in Jan/Feb. July and Aug 1943 had seen 503 and 501 aircraft built but Bell was changing over the P-63. Production of the P-63 was slow to ramp up as the engine (V-1710-93) did not pass certification until Oct/Nov. Planes built before then were flown under restrictions.

Given the mediocre to dismal outcomes for the P-39 (it was moderately helpful in the Pacific for a while but at very high cost in trained aircrew) and the very large production numbers of it, I was thinking that it might have made sense for Bell to make some of the changes they made for the P-63, i.e. lengthen the fuselage somewhat, so that it could carry a bit more fuel. Or make some other kind of improvements. Many of the total number of ~ 8,000 P-39s ended up flying in rear-areas and not seeing any combat, so slowing down production lines to introduce more substantially improved versions may have been worth the effort. I get that putting in a two speed supercharger might have been very difficult but they did put in the quasi- two-stage version in the P-63 eventually. Whatever disruption that required may have been worth it.

 

[Shortround6]

Given the mediocre to dismal outcomes for the P-39 (it was moderately helpful in the Pacific for a while but at very high cost in trained aircrew) and the very large production numbers of it, I was thinking that it might have made sense for Bell to make some of the changes they made for the P-63, i.e. lengthen the fuselage somewhat, so that it could carry a bit more fuel. Or make some other kind of improvements. Many of the total number of ~ 8,000 P-39s ended up flying in rear-areas and not seeing any combat, so slowing down production lines to introduce more substantially improved versions may have been worth the effort. I get that putting in a two speed supercharger might have been very difficult but they did put in the quasi- two-stage version in the P-63 eventually. Whatever disruption that required may have been worth it.

P-39 was a lost cause in 1941-42, If they were not going to Russian they should have just shot the whole program.
Stretching the fuselage was too much trouble for too little gain. The engine was sitting on the center of gravity. Putting fuel tanks in front of the pilot or behind the engine gives you CG problems real quick. Trying to stuff a fuel tank between the Engine and pilot may require a longer crankshaft. Possible but may require a lot of engineering time?
P-63s carried all their fuel in the wing. Different airfoil and wing construction allowed for fuel tanks behind the 1st spar instead of in front of it. Wing was thicker there for thicker fuel tanks.
The 37mm was not a good air to air gun. The cowl mounted .50s were also not a good idea. The US .50s lost a lot of rounds per minute when synchronized.
Too much had been sacrificed to get the 37mm gun in a small plane and the plane was volume limited.
In the US a lot of P-39s were used in training schools. If you don't use P-39s what do you use? P-40s? Mustangs?

 

[Steamed_Banana]

P-39 was a lost cause in 1941-42, If they were not going to Russian they should have just shot the whole program.
Stretching the fuselage was too much trouble for too little gain. The engine was sitting on the center of gravity. Putting fuel tanks in front of the pilot or behind the engine gives you CG problems real quick. Trying to stuff a fuel tank between the Engine and pilot may require a longer crankshaft. Possible but may require a lot of engineering time?
P-63s carried all their fuel in the wing. Different airfoil and wing construction allowed for fuel tanks behind the 1st spar instead of in front of it. Wing was thicker there for thicker fuel tanks.

So redesign the wing along the lines of P-63. What's to be lost? 2,000 fewer P-39s? If you ended up with 1,000 better planes with longer range it might be worth it.

The 37mm was not a good air to air gun. The cowl mounted .50s were also not a good idea. The US .50s lost a lot of rounds per minute when synchronized.
Too much had been sacrificed to get the 37mm gun in a small plane and the plane was volume limited.

Agree about the 37mm, it should have just been replaced with a 20mm like the British did for the P-400. Disagree about the cowl mounted 12.7mm. I know we have argued about this before. ROF might have been lower, but the accuracy and ease of aiming was a big bonus. The pilots of most planes that had the nose mounted guns liked them - and many with nose mounted only or nose mounted + hub cannon (better!) really liked them and there are many aircraft which did quite well, including some of the best single-seat fighters of the war in their day: Bf 109F, the Ki-27 and Ki-43, the Yak 1 / 7 / 9, the Yak 3, CR 32, 42, and MC 200, and especially the MC 202 etc. were all well-regarded fighters.

The A6M and Bf 109G, Fw 190, P-36 / Hawk 75, P-40B/C, also of course had nose guns in addition to the wing guns but they weren't in a hurry to get rid of the nose guns in them, for the most part (P-40 being the only exception that I can think of)

In the US a lot of P-39s were used in training schools. If you don't use P-39s what do you use? P-40s? Mustangs?

I don't think P-39s were great in training schools, given the very high rate of landing and takeoff accidents with them. The nose wheel seems like a great innovation but it didn't seem to help that much. Maybe the problem was the relatively high landing speed.

As for what to use instead for training schools, I mean you have a point, kind of like the argument about the Defiant being needed for target tugs. They did end up using a lot of P-40s in training units, but the US had good advanced trainers in production like the AT-6, and overall I think a lot of the surviving older versions of fighters that were a little easier to handle like the Wildcat, P-40, Buffalo, P-36 etc. could have been used (and I think were). Maybe they could also import some Hurricanes from Canada, they apparently had quite docile handling for a modern fighter.

The P-39s that were used in this role were simply pressed into it, I think, because there were so many of them and they had limited utility on the front line.

 

[andy1967]

Chief Spitfire Test Pilot Alex Henshaw's thoughts on the development of the Spitfire .

Also the full statement in context.