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

[michaelmaltby]

It is noteworthy that the Soviets used P-39Qs for photo reconnaissance ... I did not know that .... but makes great sense ... based immediately behind the front ... Qs could fly short range tactical missions. Removing belly tanks to enable this was a shrewd trade-off, IMO. Never under-estimate the Soviets.

 

[P-39 Expert]

You are comparing two different airframes, that differed in weight by 1800lbs with different types of engine, using different fuel and trying to draw a conclusion about the type of supercharger????

Lets try to compare apples to apples and not apples to brussel sprouts.

I'm comparing the performance of two fighter planes that were used at the same time in WWII, the FW190A6 and P-39N. They had different weights and different engines, mainly because they were manufactured by different countries and opposed each other in battle. P-39N was as good (at least) as the FW190A6. Government performance figures prove this.

 

[P-39 Expert]

Military power duration went to 15 minutes, both take off ans WER were set at 5 min duration (though that duration was many times exceeded in heat of combat).
Thing with backfire screens removed in mid 1942 is that it does not help the RAF in 1941 or in 1st half of 1942. The P-39D even with engines making 1150 HP at 12000 ft will not cut it against the LW opposition, while P-39M/N is too late to matter for ETO.



Fw 190 was capable to take off with much greater extenal load, almost 4000 lb total, due to having plenty of power for take off. Having the low speed S/C to choose from was worth 400-600 HP for take off. That also meant that it was capable to make 1900 HP at low level from mid-1943 on, time to climb to 26000 ft was reduced to just 8.5 min on 2700 rpm, speed went to 400+ mph above 13000 ft. link

P-39N came out in December 1942, how is that too late for the ETO?
Check your date on the linked document in the upper right corner, 12/13/1943. The air war for fighters would be basically over three months later in March 1944. Plenty of bombing and ground attack missions yet to go, but if you even saw a Luftwaffe or Japanese plane after then you were the hit of the officers club that evening. So the FW190 would have this performance for about 3 months. I'll stick with my figures for the FW190A6.

 

[Peter Gunn]

It doesn't matter if your vaunted N "came out" in December '42, it's not too late for the ETO, it's too useless for the ETO. Range is unsuitable for 8th AF escort ops, performance is useless for 8th AF escort ops at bomber altitudes, payload and range is useless for 9th AF tactical ops, no climb performance above 10,000 ft for interception duties, and on top of all that, it's too GD slow for the theater as a whole.
Not argumentative, just fact.

Also, after March of 1944 Luftwaffe fighters were so scare that just to see one made you a hit at the O club? Riiiight. Might want to rethink that gem.

 

[pbehn]

It doesn't matter if your vaunted N "came out" in December '42, it's not too late for the ETO, it's too useless for the ETO. Range is unsuitable for 8th AF escort ops, performance is useless for 8th AF escort ops at bomber altitudes, payload and range is useless for 9th AF tactical ops, no climb performance above 10,000 ft for interception duties, and on top of all that, it's too GD slow for the theater as a whole.
Not argumentative, just fact.

Also, after March of 1944 Luftwaffe fighters were so scare that just to see one made you a hit at the O club? Riiiight. Might want to rethink that gem.

If a plane has no performance above 10,000ft then if your enemy has, he just climbs straight to 10,000ft. and looks down at you laughing. This happened to early Griffon Spitfires.

 

[tomo pauk]

P-39N came out in December 1942, how is that too late for the ETO?

It does not add anything to two main tasks the day fighters were doing in the ETO from late 1942 - bomber escort at 20000-30000 ft as far as possible, and fighter-bomber duties involving a good-sized load of bombs or rockets. P-39N for ETO is a solution looking for a problem.

Check your date on the linked document in the upper right corner, 12/13/1943. The air war for fighters would be basically over three months later in March 1944. Plenty of bombing and ground attack missions yet to go, but if you even saw a Luftwaffe or Japanese plane after then you were the hit of the officers club that evening. So the FW190 would have this performance for about 3 months. I'll stick with my figures for the FW190A6.

I have no problems with you sticking with any set of numbers you prefer. LW was flying fighter missions in 1945, let alone in 1944.
The P-39M/N/Q will be fine fighters for altitudes under 15000 ft where long range is not required - talk Eastern front. As-is, they have nothing to add in ETO, Asia/Pacific and, possibly, MTO.

 

[Shortround6]

I'm comparing the performance of two fighter planes that were used at the same time in WWII, the FW190A6 and P-39N. They had different weights and different engines, mainly because they were manufactured by different countries and opposed each other in battle. P-39N was as good (at least) as the FW190A6. Government performance figures prove this.

And below 5km altitude (16500') the P-39Ns advantage in both speed and climb is huge. Now, please let me hear from all you "two speed" and crankshaft experts about how big an advantage low gear is. As you can see from the charts the two speed supercharger results in a "sawtooth" speed and climb curve while the single speed P-39N develops its maximum power at 3km (10000') and then gradually declines from there up to the combat ceiling.

You wanted to hear from us about the advantage of the low gear, you did, you just don't want to hear about it or you want to ignore it if it conflicts with your pet theory.
You remind me of an old fire captain I had, didn't know squat about hydraulics and thought if you screwed a magic nozzle on the end of the hose it did away with all the friction loss and calculations needed for different setups (different distances from pump to nozzle) .

You ignore what you don't want hear and try to change the argument.

It isn't hard to figure out that a 7300lb aircraft is going to outclimb a 9100lb aircraft. The 9100lb aircraft needs about 25% more power than the 7300lb aircraft just for starters. The FW 190 didn't have it regardless of the type of supercharger it had.
You have proved nothing about the types or advantages of superchargers.

 

[pbehn]

The Spitfire doubled in weight from first to last versions, I cant remember anyone suggesting it would have been a better plane with less guns, armour thinner skin covering etc, possibly because it was a bit of a lightweight next to a "Jug".

 

[Glider]

The Spitfire doubled in weight from first to last versions, I cant remember anyone suggesting it would have been a better plane with less guns, armour thinner skin covering etc, possibly because it was a bit of a lightweight next to a "Jug".

The special thing about the Spitfire was it did increase its weight, power firepower but it was as good as the best of the opposition, the P39 never was and was always trying to play catchup. The Spitfire didn't need to lose weight to match with the opposition
In 1940 the two best fighters in the world were the 109E and the Spitfire. When the Fw190 entered service it was the best until the Mk IX arrived on the scene. Even late war The Mk XIV was a fighter that could take on the best.
It wasn't perfect but few would deny that range was the one big problem from start to finish. That said the specialised PR versions were arguably the best PR aircraft of the war with an almost astonishing range. It wasn't a great GA aircraft but carried up to a 1000lb of bombs and some (I think) up to 1,500Lb.

The important part of this posting was it (the Spitfire) was as good as the best of the opposition, the P39 never was and was always trying to play catchup.

 

[P-39 Expert]

It doesn't matter if your vaunted N "came out" in December '42, it's not too late for the ETO, it's too useless for the ETO. Range is unsuitable for 8th AF escort ops, performance is useless for 8th AF escort ops at bomber altitudes, payload and range is useless for 9th AF tactical ops, no climb performance above 10,000 ft for interception duties, and on top of all that, it's too GD slow for the theater as a whole.
Not argumentative, just fact.

Also, after March of 1944 Luftwaffe fighters were so scare that just to see one made you a hit at the O club? Riiiight. Might want to rethink that gem.

Did you look at the graphs? P-39N performance was about the same as the FW190A6 except the P-39 climbed a lot better. No climb performance above 10000'? Did you look at the charts, post #148? Plenty of climb at all altitudes.
And yes, German and Japanese fighters were extremely scarce (or inept) after March 1944. Air superiority had been won clearing the way for the D-Day invasion in June. The Great Marianas Turkey Shoot that same June proved the Japanese were beaten when the Navy shot down 350 Japanese planes for the loss of 30 some odd Hellcats. The Axis were beaten in the air, everybody knew it and sightings of opposing fighters was indeed rare.

 

[P-39 Expert]

The special thing about the Spitfire was it did increase its weight, power firepower but it was as good as the best of the opposition, the P39 never was and was always trying to play catchup. The Spitfire didn't need to lose weight to match with the opposition
In 1940 the two best fighters in the world were the 109E and the Spitfire. When the Fw190 entered service it was the best until the Mk IX arrived on the scene. Even late war The Mk XIV was a fighter that could take on the best.
It wasn't perfect but few would deny that range was the one big problem from start to finish. That said the specialised PR versions were arguably the best PR aircraft of the war with an almost astonishing range. It wasn't a great GA aircraft but carried up to a 1000lb of bombs and some (I think) up to 1,500Lb.

The important part of this posting was it (the Spitfire) was as good as the best of the opposition, the P39 never was and was always trying to play catchup.

Continuing to disagree with you, go to wwiiaircraftperformance.org. Their latest update to the P-39 was in 2012, fairly recent for research. All the other WWII fighters are there (except Russia) with the official government docs for performance. Compare the performance graphs head to head and chronologically. You will find that the German and Japanese planes were not super planes. The P-39 had surprisingly good performance especially after all the negative propaganda you have heard about them for the last 70 years. Fascinating reading and no editorial license, just facts.

 

[pbehn]

Did you look at the graphs? P-39N performance was about the same as the FW190A6 except the P-39 climbed a lot better. No climb performance above 10000'? Did you look at the charts, post #148? Plenty of climb at all altitudes.
And yes, German and Japanese fighters were extremely scarce (or inept) after March 1944. Air superiority had been won clearing the way for the D-Day invasion in June. The Great Marianas Turkey Shoot that same June proved the Japanese were beaten when the Navy shot down 350 Japanese planes for the loss of 30 some odd Hellcats. The Axis were beaten in the air, everybody knew it and sightings of opposing fighters was indeed rare.

Oh for goodness sake, we have now entered 1944 with the P-39-N, put your performance figures against the Tempest, Spitfire Mk XIV, P51-B, Corsair and Hellcat.
It needs to escort a bomber formation, shoot down a V1 or be good at ground attack as well as just fight with an FW 190 at your chosen altitude.

 

[P-39 Expert]

Military power duration went to 15 minutes, both take off ans WER were set at 5 min duration (though that duration was many times exceeded in heat of combat).
Thing with backfire screens removed in mid 1942 is that it does not help the RAF in 1941 or in 1st half of 1942. The P-39D even with engines making 1150 HP at 12000 ft will not cut it against the LW opposition, while P-39M/N is too late to matter for ETO.



Fw 190 was capable to take off with much greater extenal load, almost 4000 lb total, due to having plenty of power for take off. Having the low speed S/C to choose from was worth 400-600 HP for take off. That also meant that it was capable to make 1900 HP at low level from mid-1943 on, time to climb to 26000 ft was reduced to just 8.5 min on 2700 rpm, speed went to 400+ mph above 13000 ft. link

Your link to the FW190 is interesting in that it is dated December 1, 1943 and in the first paragraph says that this investigation is to increase boost in the FW190A8 which began production in Feb 1944. A FW190A5 was used as test bed since they had the same engine. These increases in boost were obviously never put into service as the performance graphs for the A6 and A8 (both later models) do not reflect these performance increases. Go to the site that your link is from, wwiiaircraftperformance.org and look up the FW190A8.

 

[fubar57]

 

[Milosh]

Starting from July 1944 all Fw 190 A-8 aircraft will be equipped with "increased emergency". By overridding the supercharger boost regulator, boost pressures are increased at take-off and emergency power in low supercharger setting from 1,42 ata to 1,58 ata and at the high supercharger setting from 1,42 to 1,65 ata.

 

[drgondog]

Did you look at the graphs? P-39N performance was about the same as the FW190A6 except the P-39 climbed a lot better. No climb performance above 10000'? Did you look at the charts, post #148? Plenty of climb at all altitudes.
And yes, German and Japanese fighters were extremely scarce (or inept) after March 1944. Air superiority had been won clearing the way for the D-Day invasion in June. The Great Marianas Turkey Shoot that same June proved the Japanese were beaten when the Navy shot down 350 Japanese planes for the loss of 30 some odd Hellcats. The Axis were beaten in the air, everybody knew it and sightings of opposing fighters was indeed rare.

You might have missed the memo

P-39N came out in December 1942, how is that too late for the ETO?
Check your date on the linked document in the upper right corner, 12/13/1943. The air war for fighters would be basically over three months later in March 1944. Plenty of bombing and ground attack missions yet to go, but if you even saw a Luftwaffe or Japanese plane after then you were the hit of the officers club that evening. So the FW190 would have this performance for about 3 months. I'll stick with my figures for the FW190A6.

You have an 'interesting' view of the air war in the ETO. You are also seemingly clueless regarding 'gestation period' to introduce a new model, produce it in quantity and deploy it in Group level strength. AFAIK, four US Fighter Groups Began receiving P-39N for combat deployment in Q3/1943 - the 354th, 357th & 363rd destined for 9th AF CAS role for ETO in November-December 1943. The 332nd FG destined for 12th AF and also CAS role went to MTO in November 1943. The decision was made that the ETO bound FG's would convert immediately as the first combat deployed P-51B-1 and prepare for CAS role leading up and through D-Day. The 332nd also left the P-39Ns in the States, and converted to P-40N upon arrival, then P-47D, then P-51B/C in June 1944.

Deployment of P-39s to SWP also stopped in fall 1943. The NET-NET is that despite improved low and mid altitude performance equivalent performance against Bf 109/FW 190 the incredibly stupid leaders of the AAF came to the following convictions in mid 1943:

1.) there was no clear cut role for the P-39M/N/Q or P-63 for Any mission ranging from CAS to middle altitude escort to Recon to long range escort in which either the P-51B, the P-47D or P-38H/J was not superior - range, top speed, load carrying capability being dominant. The P-39 was very limited in range and even moreso when bombs replaced external fuel tanks. The beneficial mid altitude performance didn't matter as our bases were not close to front lines except for North Africa and SWP - and the P-39 was clobbered by the Japanese and German aircraft engaged in those timeframes.

2.) the Russians very much wanted them because their air/ground mission and tactics were entirely different and suitable for the P-39. That said the Yak 3 and Laag 7 quickly replaced the P-39s in the Guards units tasked with interceptor/air superiority role.

So, it was an easy decision by stupid leaders aware of the US Mission doctrine to decide to let Bell continue production for Russians - but quit buying Bell for AAF.

And, NO the air war in the ETO was 'not over' in March, 1944 when only four ETO FG (2-9thAF 2-8th AF) were flying Mustangs, and 3 P-38 FG, for LR Escort and just in the early phase of taking out the LW capability of inflicting unacceptable losses on 8th BC.

 

[DarrenW]

This is probably one of the most interesting and enlightening threads that I have had the pleasure NOT to be a part of......

 

[Glider]

Continuing to disagree with you, go to wwiiaircraftperformance.org. Their latest update to the P-39 was in 2012, fairly recent for research. All the other WWII fighters are there (except Russia) with the official government docs for performance. Compare the performance graphs head to head and chronologically. You will find that the German and Japanese planes were not super planes. The P-39 had surprisingly good performance especially after all the negative propaganda you have heard about them for the last 70 years. Fascinating reading and no editorial license, just facts.

I have done and must have missed something - can you point out to me where the P39 matches the 440 mph of the Spit XIV because I cannot find it, in fact I cannot find where is matches the 413mph of the Spit IX.
Or to make it easier for you, where does the P39 match the Spitfire IX climb rate at sea level of 4,700 ft/min at 7,000ft, I can only find 4,000 ft/min for the P39N. If we wish we can look at altitude but the best I can find for the P39 is 15,000 ft where I can find 3,230 ft/min. The Spit was climbing at 3,480 ft/min at approx. 25,000 ft where the P39N seems to max out at 1,940 ft/min which isn't good.
If you want to compare the P39D against a Spit V feel free.

As you say its just facts.

Edit - As a low altitude aircraft in Europe GA missions are certain. Can you tell us how the P39 compares to other aircraft in this role. I honestly have no idea of the GA capability of the P39 but suspect its little if any apart from the guns.

 

[Shortround6]

Edit - As a low altitude aircraft in Europe GA missions are certain. Can you tell us how the P39 compares to other aircraft in this role. I honestly have no idea of the GA capability of the P39 but suspect its little if any apart from the guns.

Most/all could carry one 500lb (or 600lb) bomb where the drop tank went. None were ever fitted for underwing loads in service.
I would guess that smaller bombs could be carried (singly) and the 600lb bomb was a pre-war/early war bomb that surprisingly showed up in combat reports of B-17s after you would have thought it disappeared.
Late model P-40s were turned into bomb trucks (up to three 500lbs and they rigged racks to take multiple 250s under the wings) which may help explain their use after they were outmoded as fighters, using pretty much the same basic engine as the P-39.

 

[Shortround6]

Photo of a model that illustrates the Problem of a P-39 as a bomb truck

There is only so much room between the wheel doors for stores carried on the center line

Not a lot of room for big single stores. The wing never got beefed up (nor were controls fitted) to take under wing loads except for the .50 cal gun pods.
P-63s were fitted with under wing racks for drop tanks, bombs and even rockets, the triple "bazooka" style.