SHOULD the P39 have been able to handle the Zero? Was it training or performance?

[Shortround6]

Britain didn't want the P-39 (P-400) because the reason they ordered them in 1940 was in case of a German invasion of Britain. France folded like a deck chair and the British were able to hold the Luftwaffe to a stalemate (effective victory/no invasion) in the fall of 1940 in the Battle of Britain. Lend lease was enacted in early '41 so now Britain (and Russia) will get all the American planes it needs for free. Now the completed P-400s arrived in mid 1941, there is no longer any threat of invasion by Germany. Britain is now supplying their own fighters (Spit & Typhoon) in sufficient quantity that they don't need the P-400s. But these P-400s were PURCHASED under a hard money contract and Bell expected payment. The British were broke and certainly did not want to pay hard cash for planes they could now get for free.

I'm amused by the British's shock at the P-400 performance. Did they just wake up one morning and realize the P-400 weighed too much? Hardly, they ordered them that way. The purchaser (US Army or British) contractually specified EXACTLY the way the planes were to be equipped down to the last rivet. Bell had no choice but to manufacture the planes as ordered. And I'll wager that there was a British representative (or many) stationed at the Bell plant to make sure their purchase was exactly as ordered. They did the same thing to Lockheed by ordering P-38s without turbochargers and then refused to pay when those planes didn't meet specs. Had Pearl Harbor not happened (US now urgently needed all the planes they could get) then Bell and Lockheed would have sued the pants off the British over those contracts. Plus these were brand new designs and had the normal bugs and glitches any new plane had. This is not what you read in the airplane books, but I have read this exact thing before, I did not make it up. And it makes more sense than the British being surprised by low P-400 and P-38 performance. There was no surprise.

complete and utter bollocks.

Just look at the number of books, articles and websites that claim the XP-39 flew at 390-400mph and climbed to 20,000ft in 5 minutes before the NACA ruined it by taking out the turbo charger. The P-39 may have had more complete trash written about it than practically any other fighter if we count the pages of wink and bandwidth. The XP-39 never flew at full power due to a feared drive shaft problem before the turbo was taken out. A new, heavier drive shaft was installed in all later models. What is interesting is that nobody can point to WHEN this supposed flight of 390mph and climb to 20,000f took place, no date is ever given unlike many other planes where early flights and achievements are given. Also no pilots name is mentioned. Some books/accounts even go so far as to claim it was done on the first flight. Which, given the chronic overheating problems the XP-39 had is hardly creditiable let alone the sometimes mentioned flight duration of 20 minutes for the first flight.
Test pilot took-off retracted landing gear, immediately went into a full power climb to 20,000ft, leveled off, accelerated to 390mph, slowed down, descended to airfield, lowered landing gear and landed, all in 20 minutes and in an airplane that had never flown before??????
However this little "fact" did not stop Bell from advertising/ marketing the P-39 as a 400mph fighter. The "fact" that the XP-39 was over 500lbs overweight (about 10%) when delivered to Wright field was exactly pointed out in advertising brochures either. This is for the unarmed prototype with no guns. Bell claimed the performance figures were for a 5500lb gross aircraft. When weighed at Wright field it went 6104lbs. Which makes nonsense out of a lot of the later development weight figures.
The XP-39B (original XP-39 rebuilt) doesn't fly until Nov 25th 1939. French (desperate) are already trying to buy it. In fact by April of 1940 the French have given Bell a 2 million dollar cash advance.
Now please note that the first YP-39 (2nd P-39 airframe) to fly does so on Sept 13th 1940 and the first P-400 airframe flies in April of 1941 almost a year after being ordered with contracts signed. This is rather late in the game for the British to start specifying cast iron coal fired cabin heaters or whatever they did to run the weight up to get out of the contract.
Somethings on the prototypes just did not work very well. Like the first plane had ejection slots in the nose for the machine gun cartridges but these tended to be ingested by the radiator intakes in the wing so the spent cartridges were collected in bins in the weapons bay.
Bell in 1939 and the first half of 1940 ws promoting the P-39 as a 400mph fighter and that is what the French and British thought they were buying. However the empty weight of the fighter grew by 1026lbs (although this may be debatable, this was based off the 5,849lb gross of the XP-39B which may have been under stated)
We next have a bit of shall we say "trickery" in which the first P-400 was tested in late April 1941 by both a Bell company pilot and Wing Commander Adams and speeds of 391mph at 14,350 ft are recorded (after corrections). However this aircraft differed from planes on the production line by.
1.A considerably modified fin/rudder and horizontal stabilizer/elevator assemblies. The moving parts (fabric covered) were made smaller and the fixed parts (metal covered ) made larger but the finished assemblies were a bit smaller over all than standard.
2. Different fillets were used (or eliminated) on the fixed tail surfaces.
3. Plastic wood was used around all the edges of all cockpit frame work and sanded smooth.
4. gun access doors were covered over with 0.064 sheet aluminum to prevent partial opening during flight
5. Stronger landing gear linkage installed to prevent landing gear deflecting up to two in in flight
6. Longer outlet shutters of restricted area installed on oil cooler and radiator ducts to improve local airflow.
7. Standard 6 port exhausts replaced by 12 port exhaust angled down 15 degrees as tuft testing showed local airflow to be 15 degrees below the thrust line.
8. .50 cal gun ports cleaned up
9. removal of antenna mast
10. one piece engine cover and exhaust stack fairing.
11. unspecified other modifications.
12. 20 coats of Dupont grey primer sanded between coats.
13. Standard British camouflage applied but lightly sanded to remove seams from camouflage templates.

The contract speed was 394mph at rated altitude and thus the test flights were within 1 % . The contract allowed a 4% tolerance.
However while some of the modifications could be incorporated in production aircraft some could not (like filling the the cockpit structure and the 20 coats of sanded primer) and the production aircraft fell well below this test aircraft.
A Bell company test report dated Aug 18th 1941 is supposed to show that aircraft AH579 was 20mph slower than AH 571 (the modified aircraft) had a cruise speed 24mph slower, a lower critical altitude by 250 ft and took 2 minutes and 16 seconds longer to get to 26,230 ft.

This is from "Cobra" Bell Aircraft Corporation 1934-1946 by Brich Mathews.

Now are the British to be blamed for specifying too much "stuff" in order to get out of the contract or did Bell promise way more than it could deliver?

 

[pbehn]

The predominant fighter over Germany in 1942/3 was the Me110, because it was expected allied S/E fighters couldn't reach, the issue was getting S/E fighters over Germany to take them out of the fight. This is also a question of range, since the 110 has twice the range of a 109 the same number of planes can get approx. twice as many 110s to any point of attack.

 

[Milosh]

Actually there was ~100 more Bf109s than Fw190s fighting the Allies in the west (May 1943).
http://www.oocities.org/sturmvogel_66/LWJul42.html#May43

 

[Dimlee]

The Airacobra was considered to be very suitable for low altitude operations because of the excellent view and controllability, and it was fully maneuverable at speeds above 160 mph.
...
On October 11, two aircraft flew to Gravelines and Calais and hit some enemy barges and then three Airacobras flew to Ostend, but no targets were found.

When I read that and similar information, I think that one of the reason of P-39's success in VVS was that it was NOT considered suitable for low altitude operations. Instead it developed into "high" (in terms of Eastern front) altitude interceptor or escort. Whatever critics said about Pokryshkin, probably it was very lucky match: his tactical ideas and new aircraft which allowed to try those ideas in practice.

 

[Shortround6]

Okay, mistake #1. P-47 didn't need to cruise at max continuous power. Okay, then the P-39N didn't need to cruise at max continuous power either. And yes the did need to cruise at max continuous over Europe because the Luftwaffe was the toughest enemy we faced and they controlled the air over Europe. So you went as fast as you could, period. Just to give you an idea of how tough it was, the 8th Air Force had more casualties in WWII than the MARINE CORPS. So yes, you cruised over Europe at max continuous power, if you wanted to come home.

Mistake #2, yes escorts were in relays mainly because there were different types of planes (P-38, P-47 and P-51) that all had different ranges. P-39 would have been extremely useful in the early or intermediate ranges, like the P-47 or earlier P-38.

Mistake #3, the FW 190 was the predominate fighter in the west supplemented by Me109s. Me109s were the predominate fighter in the east supplemented by the FW190. The P-39N performance compared favorably with the Messer also, would you like a graph comparing the two?

Mistake #4, you obviously have not seen this information before or you would not be vehemently denying absolutely every fact that I give you. Straight from the official tests or the pilots manual. You keep coming back with "no altitude performance, no range, tumbled, bad stall, British hated it (that one's true but not for the reasons you claim) and on and on. I'm certainly not Moses but you obviously didn't know this newer information. Try and put all that old P-39 hearsay out of your mind and objectively look at some new information.

I'm enjoying our conversations, maybe someday you will too.

Please show any documentation that escort fighters ALL cruised at max continuous?
Or even any documentation that they ALL cruised at max continuous when not escorting?
Most fighters cruised at max lean if that would give them the desired speed. Depending on mission they might fly a bit below that.
Cruising at any throttle setting that used rich mixture could significantly shorten range.
You do have to consider the performance of the aircraft and quite making blanket statements.
A late model P-47 could cruise (at 25,000ft) at 324mph while using auto lean and burning 143 gallons an hour. Pushing things a bit brings it to auto rich and 348mph using 208 gallons a minute. Is the extra 24mph worth 1 extra gallon a minute more?
BTW a late model P-47 can run at 361 mph max continuous vrs the P-39s 371-375mph at full military power (15 minute limit) so if the P-47 is in danger of going the too slow the P-39 shouldn't even be there........Hey, guess what........ it wasn't.

P-39 would have been doing good just to escort a few dozen miles past the coast. It wasn't needed, why devote the airfields, pilots, ground crews and support to such a limited range plane, see earlier discussions about range compared to the P-38 and P-47.

Sure give me a graph showing how well the 1/2 fuel P-39 can climb vs the 109. Of course the 109 doesn't have to shoot the 1/2 fuel P-39 because the P-39 won't make it back to England. You can't have it both ways. You want the speed/climb of the 1/2 fuel P-39 (or what ever it carried in that test) but you want the full range of the 110-120 gallons internal. That doesn't even work in most video games.

I deny the vast majority of your facts because they simply are not true. Just because you didn't make it up doesn't mean somebody else didn't make it up and you are repeating their falsehood.

And now you are calling me a liar as to when I saw this information.
Please look at some of the other threads on the P-39. I have been using some of this information for years. It isn't new to me.
As I have said there is an awful lot of hearsay about the P-39 and lot of it is from it's supporters.
BTW I have been pretty neutral on the P-39 tumbling and in fact tried to post an explanation about why some pilots may have thought it tumbled when it didn't. SO if you can't keep track of who is denying what the likelihood of your understanding some of the other stuff seems to be diminished.

 

[P-39 Expert]

While the YP-39 and the P-39C were being test-flown, Bell Aircraft began work on an export version of the Airacobra known as the Bell Model 14. It was to be powered by a 1150 hp Allison V-1710-E4 engine which had twelve exhaust stacks on each side rather than the usual six. France was sufficiently interested that they ordered 200 Model 14s on October 8, 1939.

All of the media hype surrounding the spectacular performance of the XP-39 prototype had caught the attention of the British Direct Purchase Commission which had visited the USA in 1940 in search of combat aircraft. Seduced by promises of 400 mph top speed, a tricycle undercarriage, heavy cannon armament, and high climb rates, the British ordered 675 examples of the Airacobra. Unfortunately, Bell's glossy advertising brochures did not distinguish between the performance of a lightly-loaded, unarmed, highly-polished experimental prototype and a production fighter heavily-loaded with military equipment and armament, and the British were to rue the day that they ever looked at an Airacobra.

In 1940, the British were desperate for combat aircraft and were willing to consider just about anything that had wings, irrespective of how poor its performance might be. Consequently, when Bell submitted specifications to the British Direct Purchase Commission for a fighter with a top speed of 400 mph, a ceiling of 36,000 feet, and a range of 1000 miles, the Commission literally salivated on the spot and ordered 675 Bell Model 14s sight unseen on April 13, 1940.

The RAF model was at first named Caribou, but the American name of Airacobra was adopted in July 1941. The British Airacobra was virtually identical to the American P-39D, but the slower-firing 37-mm cannon was replaced with the faster-firing and more reliable Hispano 20-mm cannon with 60 rounds. Two 0.50-inch machine guns were mounted in the fuselage, and four 0.30-inch machine guns were mounted in the wings. The engine of the Model 14 was the 1150 hp Allison V-1710-E4 (-35). The British serials of the Airacobras were AH570/AH739 (170 planes), AP264/AP384 (121 planes), BW100/BW183 (84 planes), and BX135/BX434 (300 planes).

Bell began test flying the first Model 14 Airacobra I in April 1941. It carried the British serial number AH570. Tested on the second British Airacobra (AH571) was a revised rudder of more angular shape and less area. Although the aircraft was delivered to England in this form, this rudder was not adopted as standard. A very small dorsal fin just ahead of the rudder became a standard feature of the RAF Airacobras and was also a distinguishing feature of the American P-39D and subsequent versions.

President Roosevelt signed the Lend-Lease Act on March 11, 1941, permitting large quantities of war supplies to be transferred to the Allies. Among the early requisitions under Lend-Lease were three P-39Cs intended for "war tests" plus a batch of 150 Airacobra IAs--the A suffix being used to distinguish between Lend-Lease and Direct Purchase machines, which were otherwise identical. In the event, only the three P-39Cs were ever delivered as British machines, and were assigned the serials DS173/DS175 (USAAF werials 40-2981, -2983, -2984). The P-39Cs could be distinguished from the British Airacobras by the four machine guns in the nose and the lack of wing guns.

The first of these P-39Cs actually arrived at RAF Colerne on July 3, 1941, followed by the other two the next day. It made its first test flight in England on July 6. However, during trials at Duxford, the performance proved disappointing. Although the test pilots praised the general ease of handling of the aircraft, the maximum speed was a shocking 33 mph lower than that anticipated. The fighter proved to be definitely inferior to the Hurricane and Spitfire in climb rate and ceiling, and the 750-yard takeoff run of the Airacobra excluded its operation from some smaller fighter airfields. There was universal shock and dismay among the RAF personnel. What had gone wrong? Bell Aircraft executives later sheepishly admitted that their performance figures had been based on the unarmed and unequipped XP-39 prototype, which weighed a ton less than the armed and equipped P-39C.

The first British-purchased Airacobras began arriving at Colerne before the end of July, joining the three P-39Cs already there. Deliveries of the Airacobra to Britain had to be made by sea, since the Airacobra lacked the range to make the Atlantic crossing. By the end of September, eleven machines had been received. No. 601 "County of London" Squadron was selected to be the first Fighter Command squadron to equip with the Airacobra.

No. 601 Squadron pilots found numerous flaws and weaknesses during their initial work-up with the the Airacobra. Some of them were a question of improving operational efficiency and pilot comfort, but others were considered essential to make the aircraft operational. Numerous modifications were made in the field in an attempt to make the aircraft suitable for combat. A master valve was introduced to allow oxygen to be turned on from the cockpit. The gunsight was modified to improve forward visibility. Changes to the ammunition tanks for the wing guns were made. Modifications were made to the cockpit harness release in order to simplify the operation. The IFF (Identification, Friend or Foe) set was removed from behind the pilot, where it obstructed aft view. A throttle control quadrant friction damper was introduced.

The Air Fighting Development Unit received a British Airacobra I on July 30. They subjected it to tests and completed their report on September 22. They found the aircraft to be pleasant to fly and easy to takeoff and land. Controls were well balanced and although heavier than those of the Spitfire at normal speeds, did not increase appreciably in weight at high speeds as they did in the Spitfire. It was difficult to hold the aircraft in a dive at high speeds unless the aircraft was trimmed nose-heavy. During a turn, the Airacobra would give ample warning of a high-speed stall by severe vibration of the whole airframe. Handling in formation and formation attacks was good, although deceleration was poor because of the plane's aerodynamic cleanliness. Take-offs and landings in close formation were not considered safe, since there was considerable difficulty in bringing the aircraft back to its original path after a swing.

The Airacobra I was powered by an Allison V-1710-E4 twelve-cylinder V in-line engine rated at 1150 hp for takeoff. Weights were 5462 pounds empty and 7845 pounds normal gross. Maximum speeds were 326 mph at 6000 feet, 343 mph at 10,000 feet, 355 mph at 13, 000 feet, 341 mph at 20,000 feet. Initial climb rate was 2040 feet per minute. With an internal fuel capacity of 100 Imp gal the Airacobra had an endurance of 1 hour 20 minutes at maximum continuous cruising speed at 6000 feet, 1 hour 5 minutes at 12,000 feet, and 1 hour 35 minutes at 20,000 feet. The true airspeeds at these altitudes were 287 mph, 327 mph, and 308 mph, respectively. Under most economical cruise conditions, the endurance increased to 3 hours 20 minutes, the relevant speeds being 183 mph at 6000 feet, 217 mph at 12,000 feet, and 215 mph at 20,000 feet. Under maximum continuous climb conditions, it took 15 minutes to reach 20,000 feet. The operational ceiling was considered to be about 24,000 feet, although there was a marked decrease in performance above 20,000 feet. At the Airacobra's rated altitude of 13,000 feet, it was 18 mph faster than the Spitfire VB. However, the speed fell off rapidly above that height, and the two planes were almost exactly matched at 15,000 feet. At 20,000 feet, the Spitfire VB was 35 mph faster and at 24,000 feet it was 55 mph faster. The ground run of the Airacobra during takeoff was 2250 feet, as compared with 1470 feet for the Hurricane II and 1590 feet for the Spitfire V.

The AFDU also did some comparative dog-fighting tests with the Airacobra against a Spitfire VB and a captured Messerschmitt BF 109E. The Airacobra and the Bf 109E carried out mock dog-fighting at 6000 feet and 15,000 feet. The Bf 109E had a height advantage of 1000 feet in each case. The Bf 109, using the normal German fighter tactics of diving and zooming, could usually only get in a fleeting shot. The Bf 109 could not compete with the Airacobra in a turn, and if the Bf 109 were behind the Airacobra at the start, the latter could usually shake him off and get in a burst before two complete turns were completed. If the Bf 109 were to dive on the Airacobra from above and continue the dive down to ground level after a short burst of fire, it was found that the Airacobra could follow and catch up to the Bf 109 after a dive of over 4000 feet. When fighting the Bf 109E below 20,000 feet, the Airacobra was superior on the same level and in a dive.

A similar trial was carried out against a Spitfire V. Although the Airacobra was faster than the Spitfire up to 15,000 feet, it was outclimbed and out-turned by the Spitfire. Unless it had a height advantage, the Airacobra could not compete with the Spitfire. If on the same level or below, at heights up to about 15,000 feet, the Airacobra would have to rely on its superior level and diving speeds and its ability to take negative "G" without the engine cutting out. Above 15,000 feet, the Airacobra lost its advantage in level speed.

The Airacobra was considered to be very suitable for low altitude operations because of the excellent view and controllability, and it was fully maneuverable at speeds above 160 mph. It was not difficult to fly at night, but the exhaust flames could be seen by another aircraft flying three miles to the rear. The flash from the nose guns was blinding, and could cause the pilot to lose not only his target but also his night vision. Firing of the nose guns caused the buildup of carbon monoxide contamination in the cockpit, and this could reach a lethal level very quickly. The guns were fairly inaccessible, and maintenance was troublesome.

By the end of September, No. 601 Squadron had received permission to take its Airacobras into action. On October 9, two Airacobras took off from RAF Manston and flew across the Channel on a "rhubarb"--a code name for a small-scale raid by fighters against targets of opportunity. On this raid, they shot up an enemy trawler near Gravelines. The next day two Airacobras visited the same area, but found no targets. On October 11, two aircraft flew to Gravelines and Calais and hit some enemy barges and then three Airacobras flew to Ostend, but no targets were found.

After these four missions, the RAF Airacobras were taken off operations because of difficulties encountered with the compass. The compass was too close to the guns in the nose, and when the guns were fired, the compass got thrown out of alignment. Deviations of anything from 7 degrees to 165 degrees were recorded. Without a reliable compass, pilots tend to get themselves lost. In December of 1941, the Airacobra was officially withdrawn from operational service with the RAF.

In spite of the problems with the compass and the need for flame dampers for the exhaust and flash suppressors for the nose guns, the RAF concluded that the Airacobra would make an excellent day fighter at altitudes below 20,000 feet and was well suited for the ground-attack role. However, before these plans could be implemented, a decision was made to divert the bulk of the British Airacobra contract to Russia.

By the time this decision was made, production of British-contract Airacobras had reached four a day at Bell's Buffalo plant. The initial contract for 170 planes (RAF serials AH570 thru AH739) had been completed before the end of September, and all but six of these planes had actually been shipped to Britain. However, many of them remained in their crates and were shipped directly to the Soviet Union without being opened. Somewhere between 80 and 100 Airacobras were assembled and flown in Britain by the end of 1941. They were gathered at maintenance units for final modification before being re-crated and shipped to the Soviet Union during 1942. In all, the Soviet Union received 212 of the British Airacobras (some of them shipped direct from the USA), but 49 more were lost at sea en route.

No 601 Squadron relinquished its 13 Airacobras in March of 1942 in favor of Spitfires. One Airacobra was fitted with an arrester hook and was used for deck landing trials at the RAE at Farnborough.

After Pearl Harbor, the USA found itself in desperate need of aircraft to stem the Japanese onslaught in the Pacific. Consequently, nearly 200 of the British direct-purchase Airacobras still in the USA were promptly requisitioned by the USAAC. Although they were similar to the USAAC's P-39Ds, they were not identical and were known by the USAAC under the non-standard designation of P-400. The P-400 designation had, in fact, been associated with the British Airacobras for contractual purposes as early as August 1941. The USAAC P-400s retained their original British serial numbers and their three-color camouflage paint. Most of these planes were used for training stateside, but some of them were rushed to the Southwest Pacific in an attempt to stem the onrushing Japanese advance.

Thanks for reprinting the company line, we have all read that.

Paragraph 1, Bell actually began work on the P-400 right after the purchase contract in 1940 and was produced on the same assembly line as the P-39Cs and later P-39Ds. British planes differed only slightly (20mm cannon and 4 wing .30s) from production P-39s.

Paragraph 2, The British read the glossy hype? British know that the prototype P-39s only weighed around 6000# and they also knew that their P-400s would weigh more since they specified EVERY piece of equipment in their contract. This was absolutely no surprise to the British.

Paragraph #3, in 1940 the British (and French) WERE absolutely desperate for aircraft, but in no way did they believe for one second that any P-39 with the 1150HP engine would do 400mph, especially at 7850# after installation of the armor plate/glass and self sealing tanks that were REQUIRED BY THE BRITISH.

Paragraph 4, agree.

Paragraph 5, note the distinction between Lend Lease planes and Direct Purchase (contracted) planes. The British were paying CASH for the contracted planes. But now free lend lease planes were available. What would you do if you were the British? Well you would do your best to get out of the CONTRACT and get the free lend lease planes.

Paragraph 6 and 7, love this, the British were "shocked and dismayed" at the lack of performance. This from a plane that clearly weighed a lot more than the original because the British had specified that heavier plane in the contract. British were hardly shocked, they knew exactly what they ordered and how it was produced. Bell never "sheepishly" admitted anything, that would be fraud. Again, the British knew exactly what they ordered and received, any "shock and dismay" was for the benefit of publicly weaseling out of the contract. And remember the British found it "pleasant to fly, easy to take off and land, good for formation flying, ample stall warning, and an excellent day fighter at altitudes below 20000'" even at this grossly overweight form.

Paragraph 8,9. These were problems encountered by any brand new plane and were all corrected quickly in production models. No more faulty compasses etc.

Paragraph 10, The British performance tests differed somewhat from Bell's tests. Bell got 371mph at 14000' and a service ceiling of over 35000' from the P-400 at gross weight. Contemporary Spitfire V was good for about 366mph just for comparison and weighed about 6600# instead of 7850#. That's 1200# if you do the math. I probably should prepare a graph for you with the early P-39/P-400 and the Spitfire V so you can see a direct comparison.

If you believe for one second that the British didn't know exactly what they were getting at every stage of P-400 construction, then I have ocean front property in Arizona to show you. Their situation had changed drastically since the 1940 order, they didn't need the planes, and they sure didn't want to pay cash money for them. Believe what you want.

 

[pbehn]

When I read that and similar information, I think that one of the reason of P-39's success in VVS was that it was NOT considered suitable for low altitude operations. Instead it developed into "high" (in terms of Eastern front) altitude interceptor or escort. Whatever critics said about Pokryshkin, probably it was very lucky match: his tactical ideas and new aircraft which allowed to try those ideas in practice.

When fighting is on a land front the simple fact that forces are in contact brings all air fighting down. If you bomb from 20,000 ft you are as likely to hit your own guys as the enemy. Almost all activity is to hit something on the ground and so activity is near the ground. The Tempest was introduced before D-Day but after D-Day there was no need or demand for it to be optimised for high altitude performance.

 

[pbehn]

Thanks for reprinting the company line, we have all read that.

Paragraph 1, Bell actually began work on the P-400 right after the purchase contract in 1940 and was produced on the same assembly line as the P-39Cmn and later P-39Ds. British planes differed only slightly (20mm cannon and 4 wing .30s) from production P-39s.

Paragraph 2, The British read the glossy hype? British know that the prototype P-39s only weighed around 6000# and they also knew that their P-400s would weigh more since they specified EVERY piece of equipment in their contract. This was absolutely no surprise to the British.

Paragraph #3, in 1940 the British (and French) WERE absolutely desperate for aircraft, but in no way did they believe for one second that any P-39 with the 1150HP engine would do 400mph, especially at 7850# after installation of the armor plate/glass and self sealing tanks that were REQUIRED BY THE BRITISH.

Paragraph 4, agree.

Paragraph 5, note the distinction between Lend Lease planes and Direct Purchase (contracted) planes. The British were paying CASH for the contracted planes. But now free lend lease planes were available. What would you do if you were the British? Well you would do your best to get out of the CONTRACT and get the free lend lease planes.

Paragraph 6 and 7, love this, the British were "shocked and dismayed" at the lack of performance. This from a plane that clearly weighed a lot more than the original because the British had specified that heavier plane in the contract. British were hardly shocked, they knew exactly what they ordered and how it was produced. Bell never "sheepishly" admitted anything, that would be fraud. Again, the British knew exactly what they ordered and received, any "shock and dismay" was for the benefit of publicly weaseling out of the contract. And remember the British found it "pleasant to fly, easy to take off and land, good for formation flying, and ample stall warning, and an excellent day fighter at altitudes below 20000'" even at this grossly overweight form.

Paragraph 8,9. These were problems encountered by any brand new plane and were all corrected quickly in production models. No more faulty compasses etc.

Paragraph 10, The British performance tests differed somewhat from Bell's tests. Bell got 371mph at 14000' and a service ceiling of over 35000' from the P-400 at gross weight. Contemporary Spitfire V was good for about 366mph just for comparison and weighed about 6600# instead of 7850#. That's 1200# if you do the math. I probably should prepare a graph for you with the early P-39/P-400 and the Spitfire V so you can see a direct comparison.

If you believe for one second that the British didn't know exactly what they were getting at every stage of P-400 construction, then I have ocean front property in Arizona to show you. Their situation had changed drastically since the 1940 order, they didn't need the planes, and they sure didn't want to pay cash money for them. Believe what you want.

Oops sorry, I believe I have committed plagiarism, my post was lifted from this website.
Joe Baugher's Home Page
He quotes the following sources, maybe you should get in touch and put him right, easy enough he lives in the USA.
Sources:

1. War Planes of the Second World War, Fighters, Volume Four, William Green, Doubleday, 1964.
   
   
2. The American Fighter, Enzo Anguluci and Peter Bowers, Orion Books, 1987.
   
   
3. United States Military Aircraft since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian Institution Press, 1989.
   
   
4. P-39 Airacobra in Action, Ernie MCDowell, Squadron/Signal Publications, 1980
   
   
5. The Calamitous 'Cobra, Air Enthusiast, August 1971.
   
   
6. Airacobra Advantage: The Flying Cannon, Rick Mitchell, Pictorial Histories Publishing Company, Missoula, Montana
   
   
7. Airacobra Advantage--The Flying Cannon, Rick Mitchell, Pictorial Histories Publishing Company, 1992
   
   
8. Bell Cobra Variants, Robert F. Dorr, Wings of Fame, Vol 10, AirTime Publishing , Inc., 1998.
   
   
9. E-mail from Gordon Birkett on disposition of AP347, BW169, AP361, plus serial numbers on USAAF P-400s.
   
   
10. E-mail from Terence Geary on P-400 dispositions.
    
    
11. Andrew Thomas, Bell Airacobra In RAF Service, International Air Power Review, Vol 6, 2002
    
    
12. E-mail from Franek Grabowski on AH728, AH733, AH737, BW118, BX302.
    
    
13. E-mail from Nick Jenkins on crash of AH573.
    
    
14. E-mail from Andrew Linden on loss of BX165

 

[Elmas]

*snip*
Bell had no choice but to manufacture the planes as ordered. And I'll wager that there was a British representative (or many) stationed at the Bell plant to make sure their purchase was exactly as ordered.
*snip*

In 1939, things did not happen as they do today in 2018.
At that time the bureaucracy and the bureaucrats were reduced to a minimum, and were not running the tons of paper that today run in a public contract.

When the British Commission asked for substantial modifications to Lockheed Super Electra to have a maritime patrol reconnaissance aircraft, the Lockheed team bought a drawing board, paper, pencils a slide rule and put a very young Kelly Johnson at work in his hotel room.

"I did work continuously for three days" Johnson recalls "and then I slept for twenty four hours…"
The British signed the contract.

And also the Skyrider was designed overnight ( as a general appearance and main specifications, of course) in a hotel room.

Bell Company had blown the trumpet a lot about the performances of P-39 so the British Commission had no reason whatsoever for not believing to them: the shortcomings of P-39 were by far more subtle to discover.

 

[pbehn]

If you believe for one second that the British didn't know exactly what they were getting at every stage of P-400 construction, then I have ocean front property in Arizona to show you. Their situation had changed drastically since the 1940 order, they didn't need the planes, and they sure didn't want to pay cash money for them. Believe what you want.

Can you stop making this ridiculous assertion. It stems from your obsession with the P-39 to the exclusion of all other planes and all other events, even the US declaration of war itself. The "British" you are referring to is the government not some cash strapped airline. In 1942 airfields were being completed at the rate of 1 every three days, a project equal to building a road from UK to China employing 60,000 people. They were building and operating four engine bombers, fighting the battle of the Atlantic etc etc etc. In the midst of this, your tin pot order of 675 fighters amounts to less than a months production, it is zero, zilch, nada in the scheme of things in a war. The needs of Russia in its land war and the needs of the USA defend its own interests abroad and to train pilots were considered much greater than the need of the UK to strafe the "Pas de Calais" which is all the P-39 could do.

On the Schweinfurt Regensburg raid of 1943 the RAF escorted US bombers with Spitfires to Antwerp, the US escorted as far Eupen with P-47s, the idea that the people involved "missed something" with the P-39N is an insult to everyones intelligence,

 

[Shortround6]

When I read that and similar information, I think that one of the reason of P-39's success in VVS was that it was NOT considered suitable for low altitude operations. Instead it developed into "high" (in terms of Eastern front) altitude interceptor or escort. Whatever critics said about Pokryshkin, probably it was very lucky match: his tactical ideas and new aircraft which allowed to try those ideas in practice.

Oops sorry, I believe I have committed plagiarism, my post was lifted from this website.
Joe Baugher's Home Page
He quotes the following sources, maybe you should get in touch and put him right, easy enough he lives in the USA.
Sources:

1. War Planes of the Second World War, Fighters, Volume Four, William Green, Doubleday, 1964.
   
2. E-mail from Andrew Linden on loss of BX165

Sorry to tell you but Mr Baugher (who has for the most part a very excellent site/resource) bought the XP-39 390mph flight.
which never happened and started this whole saga.
As near as I can figure the XP-39 goes like this.
The XP-39 was delivered (in crates) to Wright field Dec 17th, 1939. Assembly, final fitting of details and trying to solve leaks in the integral fuel tanks kept the plane from flying in the Jan fighter trials. The plane was supposed to hold 200 gallons of fuel max, I have no idea if this was "normal" or if a lesser mount was considered normal and the 200 gallons was considered overload. I suspect the latter as 1200lbs of fuel would be a tremendous load for a 5500-6100lb airplane.
In any case teh XP-39 began taxi trials on March 1st 1939 and promptly ran into overheating problems (not good in March in Ohio) but the engine was quickly removed by Allison for upgrading and not replaced until March 25th at which point ground testing of the engine and supercharger began.
We then have some conflicting dates. One date of April 5th says that a roughness in engine running was detected between 570 and 1400rpm and only 2650rpm could be reached instead of 3000rpm due to vibrations reaching the magneto drive. Allison had already been working on a new type Hydraulic vibration damper but work went ahead using the original vibration damper to prepare for the first flight. It is at this point that problem with extension shafts to the propeller is discovered. Allison suggests using the original shafts for initial test flying and keeping the engine out of the problem speed range, while they design new ones ( 1/8in larger in diameter with thicker wall sections) Army thinks this is unsafe and this is borne out by tests done on a ground rig at the Allison factory.
In any case the first flight (20 minutes) is done by James Taylor USNR on April 6th.
No record exists for a flight in which either 390mph was reached or 20,000ft achieved in 5 minutes.

Now as flight testing procedes cooling problems with both engine coolant and oil crop up and added/revised scoops are fabricated and fitted along with an enlarged inlet for the turbo-supercharger.
On April 21st General Arnold issues an order that the XP-39 is to be sent to Langley for testing in the wind tunnel as soon as the acceptance tests are completed and these are to be expedited.
among Gen. Arnold's recommendations just 15 days after first flight are.

A. The Fuselage will be streamlined to accommodate a pilot not over 5 feet 8 inches tall and weighing not more than 160lbs.
C. No consideration will be given to a baggage compartments if this adversely affects performance
D. The design fuel load will be for one hour at full throttle at the critical altitude.
F. Flaps will be manually operated.

From this we can reasonably conclude That Gen Arnold was suggesting both drag reduction and weight reduction was needed just 2 weeks after the first flight and well before the XP-39 made it to Langley (which it did in June of 1939).
Hardly what one would expect for plane that demonstrated a 390mph speed in April of 1939.

The heaver drive shafts that allowed full 3000rpm operation were not installed until the plane was being converted to the XP-39B configuration.

 

[Glider]

I do get a little annoyed when you keep saying the British tried to get out of the contract. Have you got any evidence to support that, if so put it up or stop saying it.

 

[Glider]

Britain didn't want the P-39 (P-400) because the reason they ordered them in 1940 was in case of a German invasion of Britain. France folded like a deck chair and the British were able to hold the Luftwaffe to a stalemate (effective victory/no invasion) in the fall of 1940 in the Battle of Britain. Lend lease was enacted in early '41 so now Britain (and Russia) will get all the American planes it needs for free. Now the completed P-400s arrived in mid 1941, there is no longer any threat of invasion by Germany. Britain is now supplying their own fighters (Spit & Typhoon) in sufficient quantity that they don't need the P-400s. But these P-400s were PURCHASED under a hard money contract and Bell expected payment. The British were broke and certainly did not want to pay hard cash for planes they could now get for free.

This part of the post is a copy from earlier and as comprehensively proven to be wrong on almost every level and word. Putting it in here is only a distraction adds nothing apart from trying to cause confusion

I'm amused by the British's shock at the P-400 performance. Did they just wake up one morning and realize the P-400 weighed too much? Hardly, they ordered them that way.

Your right but Bell still promised to deliver the performance so your statement should say I'm amused by Bells shock at the P-400 performance. Did they just wake up one morning and realize the P-400 weighed too much after all they build the aircraft and know the impact of extra weight?
Interestingly I can see how this happens. I used to work for a major IT company as a senior Project manager/Program Manager and my niche was projects that had gone wrong or were about to go wrong. The number of times the salesmen made a promise to get the contract signed and get their bonus, then leave it up to the developers to sort it out was astonishing.

The purchaser (US Army or British) contractually specified EXACTLY the way the planes were to be equipped down to the last rivet. Bell had no choice but to manufacture the planes as ordered.

Fundamentally and legally wrong. Any change to a project has to be agreed and signed off. If Bell had a problem with any extra kit impacting the performance they had every opportunity to change the performance guarantees in the contract.

And I'll wager that there was a British representative (or many) stationed at the Bell plant to make sure their purchase was exactly as ordered.

Standard practice in any contract of any nature.

They did the same thing to Lockheed by ordering P-38s without turbochargers and then refused to pay when those planes didn't meet specs.

I do hope you can prove that statement as we paid all our obligations even though it almost bankrupted us.

Had Pearl Harbor not happened (US now urgently needed all the planes they could get) then Bell and Lockheed would have sued the pants off the British over those contracts.

And they would have lost the case

Plus these were brand new designs and had the normal bugs and glitches any new plane had. This is not what you read in the airplane books, but I have read this exact thing before, I did not make it up. And it makes more sense than the British being surprised by low P-400 and P-38 performance. There was no surprise.

The reasons differ but I suspect you know that. The P39 didn't deliver close to what Bell promised, The P38 did deliver the expected performance but we needed high altitude aircraft and wanted to convert a majority of the order to Standard P38E aircraft and it was that change which caused the rancor. Please note that one reason for the British (and French) original order lacking turbochargers wasn't that we didn't want them, we did, but there was a ban on the export of certain technology from America and the Turbochargers were part of that ban. Once the war started for the USA that ban was lifted

 

[pbehn]

Sorry to tell you but Mr Baugher (who has for the most part a very excellent site/resource) bought the XP-39 390mph flight.
which never happened and started this whole saga.
As near as I can figure the XP-39 goes like this.
The XP-39 was delivered (in crates) to Wright field Dec 17th, 1939. Assembly, final fitting of details and trying to solve leaks in the integral fuel tanks kept the plane from flying in the Jan fighter trials. The plane was supposed to hold 200 gallons of fuel max, I have no idea if this was "normal" or if a lesser mount was considered normal and the 200 gallons was considered overload. I suspect the latter as 1200lbs of fuel would be a tremendous load for a 5500-6100lb airplane.
In any case teh XP-39 began taxi trials on March 1st 1939 and promptly ran into overheating problems (not good in March in Ohio) but the engine was quickly removed by Allison for upgrading and not replaced until March 25th at which point ground testing of the engine and supercharger began.
We then have some conflicting dates. One date of April 5th says that a roughness in engine running was detected between 570 and 1400rpm and only 2650rpm could be reached instead of 3000rpm due to vibrations reaching the magneto drive. Allison had already been working on a new type Hydraulic vibration damper but work went ahead using the original vibration damper to prepare for the first flight. It is at this point that problem with extension shafts to the propeller is discovered. Allison suggests using the original shafts for initial test flying and keeping the engine out of the problem speed range, while they design new ones ( 1/8in larger in diameter with thicker wall sections) Army thinks this is unsafe and this is borne out by tests done on a ground rig at the Allison factory.
In any case the first flight (20 minutes) is done by James Taylor USNR on April 6th.
No record exists for a fight in which either 390mph was reached or 20,000ft achieved in 5 minutes.

Now as flight testing procedes cooling problems with both engine coolant and oil crop up and added/revised scoops are fabricated and fitted along with an enlarged inlet for the turbo-supercharger.
On April 21st General Arnold issues an order that the XP-39 is to be sent to Langley for testing in the wind tunnel as soon as the acceptance tests are completed and these are to be expedited.
among Gen. Arnold's recommendations just 15 days after first flight are.

A. The Fuselage will be streamlined to accommodate a pilot not over 5 feet 8 inches tall and weighing not more than 160lbs.
C. No consideration will be given to a baggage compartments if this adversely affects performance
D. The design fuel load will be for one hour at full throttle at the critical altitude.
F. Flaps will be manually operated.

From this we can reasonably conclude That Gen Arnold was suggesting both drag reduction and weight reduction was need just 2 weeks after the first flight and well before the XP-39 made it to Langley (which it did in June of 1939).
Hardly what one would expect for plane that demonstrated a 390mph speed in April of 1939.

The heaver drive shafts that allowed full 3000rpm operation were not installed until the plane was being converted to the XP-39B configuration.

In all this what I find particularly frustrating are statements on the lines of the British should never have believed that the "P-400" would do 400 MPH, well it was called the P-400 for a reason. You can expect a drop in performance adding BP glass self sealing tanks and guns, but those items don't weigh a ton.

Anyone saying that the British couldn't have believed what they were told unless they were stupid may wish to consider the following.

1. The British believed the claims of NAA and backed them, the plane they built did everything they said it would and hence we had the P51 Mustang, ordered initially off the drawing board.
2 The first twin stage Merlin engine was bench tested in April 1941, work began in March 1940.
3 in Feb 1940 the order for 2 prototype Gloster jets was placed and the first flew in May 1941.

Bells claims, seen by the British were easily believable, it only showed that Bell/Allison were about 6/12 months ahead of RR/Supermarine

 

[Dimlee]

When fighting is on a land front the simple fact that forces are in contact brings all air fighting down. If you bomb from 20,000 ft you are as likely to hit your own guys as the enemy. Almost all activity is to hit something on the ground and so activity is near the ground. The Tempest was introduced before D-Day but after D-Day there was no need or demand for it to be optimised for high altitude performance.

Indeed.
But my point is that the tactics applied to P-39 in Soviet VVS has benefited this aircraft "image" overall in USSR. (Until it was somewhat forgotten during Cold War). Should someone decided to use her in the less smart way, this aircraft could get negative publicity among the pilots, with complaints about "another crap Allied plane" which would impact decisions made at the top about further deployment and purchasing. Add to that lobbying efforts of leading Soviet designers who tried hard to prove their worth to the country leadership and who did not shy to tarnish reputations of other aircraft, foreign or made by fellow countrymen.
There were instances in VVS when prospective models were abandoned and left without production lines to develop, - just because they were used in the wrong way and in the wrong time/place.

 

[fubar57]

 

[tomo pauk]

...
The P39 didn't deliver close to what Bell promised, The P38 did deliver the expected performance but we needed high altitude aircraft and wanted to convert a majority of the order to Standard P38E aircraft and it was that change which caused the rancor. Please note that one reason for the British (and French) original order lacking turbochargers wasn't that we didn't want them, we did, but there was a ban on the export of certain technology from America and the Turbochargers were part of that ban. Once the war started for the USA that ban was lifted

I agree with the rest of the post, but not with some things from this part of the post.
There was no ban on US turbochargers to be exported to the UK. Standard P-38 was with turbo, French and UK ordered the non-turboed Lighning Is. Engine choice were the V-1710 C15 engines for sake of commonality with P-40s ordered. After France folded, UK took over whole order, and changed it to a handful of Lightnig Is and majority of Lightning IIs (with turbos and F series engines).
Lockheed squandered months and months of time, the most precoius comodity, in quest to:
a) redesign the XP-38 into YP-38
b) make the Ligthning I as a sibling of XP-38 (engine series) and YP-38 (rest of the A/C, sans turbo)
Thus, once the Lightning I was tested in Winter of 1941/42 and Spring of 1942 in Britain, RAF saw it as an expensive fighter without a role, incapable to offer anything over the P-40B/C or Spitfire V, while having plenty of shortcomings apart the price.

 

[Shortround6]

If there was a ban it disappeared somewhere between March of 1940 when the British order 143 model 322s without the turbo superchargers and June 5th of 1940 when they order 524 Lighting MK 2s with Turbo Superchargers.

Mighty short lived if it existed.

 

[Shortround6]

Indeed.
But my point is that the tactics applied to P-39 in Soviet VVS has benefited this aircraft "image" overall in USSR. (Until it was somewhat forgotten during Cold War). Should someone decided to use her in the less smart way, this aircraft could get negative publicity among the pilots, with complaints about "another crap Allied plane" which would impact decisions made at the top about further deployment and purchasing. Add to that lobbying efforts of leading Soviet designers who tried hard to prove their worth to the country leadership and who did not shy to tarnish reputations of other aircraft, foreign or made by fellow countrymen.
There were instances in VVS when prospective models were abandoned and left without production lines to develop, - just because they were used in the wrong way and in the wrong time/place.

In the Soviet Union in 1941-43 there was a real lack of high altitude engines and not from want of trying or desire (they tried turbo-charging everything short of the diesel engine from the T-34 tank) and the two most common fighter engines. The VK-105 and the ASh-82 just weren't very good for several reasons. Getting 1150hp at 12,000ft was beyond the reach of the VK-105 and 1125hp at 15,500 was a miracle.
For instance the VK-105PA was rated at 1100hp at 6500ft(2000m) and 1050hp at 13200ft (4000M) and when they went to the VK-105PF power went to 1260hp at 2300ft (700m) in low gear and 1180hp at 8900ft (2300M) above 13200ft the performace was the same?
Please note that when pressure in later in engines was increased they went from 1050mm to 1100mm which is about 2in of increased presure or about 1lb.
The ASh-82F had 1300hp at 17,700ft (5400M) but the radial engine has more drag. The ASh-82FN had 1460hp at 15250(4650m) The Russians constantly worked at reducing drag.
The only Russian built aircraft with more high altitude performance was the Mig-3 and they were out of production. The P-39 could slide right on in as a medium altitude fighter in Russia.

 

[pbehn]

If there was a ban it disappeared somewhere between March of 1940 when the British order 143 model 322s without the turbo superchargers and June 5th of 1940 when they order 524 Lighting MK 2s with Turbo Superchargers.

Mighty short lived if it existed.

I don't know if it was a ban or a restriction on who gets what mainly concerned with the far east.

Export Control Act - Wikipedia