P39 range was awful like the Me109. Fw190 learned that Battle of Britain lesson of not just getting there but time to dogfight and get back.
Groundhog Thread Part Deux - P-39 Fantasy and Fetish - The Never Ending Story (Mods take no responsibility for head against wall injuries sustained)
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GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
Between 15 April 1943 and 25 April 1945, Hartmann claimed 81 P-39s.
My guess is he didn't think much about them...
He completed training in 1942 and was assigned to Jg52 in the autumnl of '42. That is rather mid war, not the 'early part'.
P-39 Expert
Non-Expert
Not quite as bad as a 109. With a drop tank in NG escort missions were a little over three hours.
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1st kill in Nov 1942, 2nd kill Jan 1943. This is debatable, but I'd not call that period of war as the early one. As for old aircraft, he claimed U-2, R-5, I-16 at the beginning of his career. That was probably all.
Data from this table:
Aces of the Luftwaffe - Erich Hartmann
Shortround6
Major General
In Europe with a 75 gallon drop tank it would be around 2 1/2 hours, or less.
Forget the B-17 escort stuff. Most fighters in Europe cruised at around 300mph when in enemy airspace not the just under or just over 200mph that was often used in the Pacific.
fuel burn was doubled while miles traveled only went up around 50%.
P-39 Expert
Non-Expert
These were bomber/transport escort missions per Edwards Park in his book "Angels Twenty". They ran their 110 gallon drop tanks dry at one hour and 40 minutes and often had enough fuel before landing for a "rat race" where the leader took them on a wild ride and the rest of the squadron tried to catch him. At 3 hours and, say, 12 minutes they would have burned about 66gph on 230 gallons less TO allowance of 20 gallons. These were not Pacific missions over water where enemy contact was unlikely, but missions to Wau, Lae etc. that were overland less than 200 miles away and enemy contact would be imminent.
Those guys didn't really consider the transport escort missions as combat, but the AAF gave them medals for completing X combat missions which included those. The transports were sometimes attacked, but usually just the tail end of the mission after most of the escort was already gone and didn't have the fuel to turn back and fight.
MiTasol
1st Lieutenant
Join Classic Aircraft Blueprints, Drawings & Manuals | AirCorps Library and you can get many of the original factory drawings
Not sure if this has been posted before,
http://zenoswarbirdvideos.com/Images/P-39/P39FOIC.pdf
http://zenoswarbirdvideos.com/Images/P-39/P39FOIC.pdf
P-39 Expert
Non-Expert
Only about a million times.
Shortround6
Major General
Thank you, there are manuals on this site that give similar but not complete charts. Just first and last columns.
The P-39 was cursed (many planes would have loved to have been so cursed ) with being the 2nd lowest drag fighter aircraft the US had. What this means in this case it that it suffered disproportionately compared to many other fighters when you hung a drop tank on it. That or the drop tank installation was really crappy.
At 9,000ft the P-39K&L was supposed (according the charts in the manual) at 1600rpm and 28.5in MAP do 194mph true while burning 35gph while carrying a 75 gallon tank.
At 9,000ft the P-39K&L was supposed at 1600rpm and 26.0 in MAP do 230mph true while burning 32gph while clean.
At 9,000ft the P-39K&L was supposed at 2600rpm and 37.55in MAP do 285mph true while burning 106gph while carrying a 75 gallon tank.
At 9,000ft the P-39K&L was supposed at 2600rpm and 37.5 in MAP do 340mph true while burning 105gph while clean.
I am sure the 109 posted some similar reductions in speed when carrying the drop tank.
The P-39 was cursed (many planes would have loved to have been so cursed ) with being the 2nd lowest drag fighter aircraft the US had. What this means in this case it that it suffered disproportionately compared to many other fighters when you hung a drop tank on it. That or the drop tank installation was really crappy.
At 9,000ft the P-39K&L was supposed (according the charts in the manual) at 1600rpm and 28.5in MAP do 194mph true while burning 35gph while carrying a 75 gallon tank.
At 9,000ft the P-39K&L was supposed at 1600rpm and 26.0 in MAP do 230mph true while burning 32gph while clean.
At 9,000ft the P-39K&L was supposed at 2600rpm and 37.55in MAP do 285mph true while burning 106gph while carrying a 75 gallon tank.
At 9,000ft the P-39K&L was supposed at 2600rpm and 37.5 in MAP do 340mph true while burning 105gph while clean.
I am sure the 109 posted some similar reductions in speed when carrying the drop tank.
P-39 Expert
Non-Expert
Bell developed a fairing that enclosed the attachment fittings and sway braces that supposedly increased speed by 18mph, but I have only seen the fairing in a very few photos, all on training flights.
MIflyer
1st Lieutenant
I believe that Hartmann said, "The P-39 performed like the 109 down low." But a book by a WWII German test pilot said he was quite unimpressed with the P-39's speed, although I think the example he ferried had the gear stuck partially down.
In "P-39/P-400 Airacobra vs A6M2/3 Zero-Sen" author Michael John Claringbould calls the combat losses about equal for the two. In "Twelve to One V Fighter Command Aces of the Pacific War" one of the pilots writes he was sorry to see the P-39Ns go for P-47s, because the N model Airacobra would out climb the Japanese fighters.
From WWII Aircraft Performance P-40 and P-39 performance figures a few days apart at the same airfield.
P-39 Expert
Non-Expert
I believe the critical altitude for the P-39C may be incorrect. The original document shows 13,050' but the retyped (for clarity) chart shows 16,100'. May be just confusing the C with the N whose critical altitude is listed as 16,100.
The C model is the AAF version of the P-39 that was being produced concurrently with the export P-400 for Britain. The AAF C version was much lighter than the P-400 (7075# vs. 7850#) and consequently had much better performance. Speed was a bit higher (379 vs. 371) but climb was off the chart better at 1000fpm more than the P-400 (3720fpm vs. 2720fpm).
The C model did not have armor plate and self sealing fuel tanks (like the P-400) but these would not increase the gross weight of the P-39C. The tanks weighed 240# and the armor plate weighed an astonishing 292#. The Brits went a little overboard with the armor using it to protect such items as the oxygen bottles, reduction gear etc. A normal use of the armor plate/glass would have located armor fore and aft of the pilot and behind the oil tank resulting in a weight penalty of about 130# instead of 292#.
So, add the self sealing tanks (240#) and the more sensible armor (130#). Then lose the 2 .30caliber MGs in the nose (100#) so that the full 30round magazine can be restored to the 37mm cannon (add back 30#). Net weight increase is 300# (240+130-100+30=300#) but the self sealing fuel tanks reduced fuel capacity from 170gal to the standard 120gal. That 50 gallon reduction is equal to 300#. The 300# weight increase was offset by the 300# less fuel resulting in the same 7075# gross weight. The resulting P-39C would have had self sealing tanks, armor plate/glass and armament of a 37mm cannon and two synchronized .50 MGs. And performance at least equal to the Spitfire V currently in service.
Shortround6
Major General
There were only 20 P-39Cs built out of 80 ordered. The US Army decided they wanted self sealing tanks and armor, they didn't pick u British leftovers.
The contract was amended so that the last 60 planes would incorporate the protective measures along with some other changes. It also delayed delivery of the 60 planes until some of the foreign orders (French order picked up the British for example) were completed or at least initial deliveries made.
These last 60 US planes were the P-39D, plain D not D-1 or D-2. there were a further 394 plain "D"s ordered.
I would note there was no restoration of the 30 round ammo capacity for the 37mm gun as it never had 30 rounds on the YP-39s, some of which never got any guns at all and the XP-39 never carried guns.
I believe the reduction gear armor was more of a counterweight than a real need to protect the reduction gear. They needed some weight as far forward in the plane as they could get it and right behind the prop was the far forward location.
You took an easy 70lbs out of the nose with the .30 cal guns and ammo gone, they added armor to the rear of the plane.
On the later planes it was and airplane that was not supposed to flown without ammo for the nose guns unless ballast was carried. It was more than a bit sensitive to the center of gravity.
I would note for the British the 20mm gun weighed about 130lbs compared to the 238lbs of the 37mm gun. and the 20mm ammo and drum were lighter than the 37mm ammo.
radios are all over the place when it comes to weight (and I have no idea why later P-39s picked up about 50lbs of electrical system weight vs the P-39D. (please note the are weight categories for communications as well as radios in addition to the electrical system.)
P-39 Expert
Non-Expert
I agree with you on the reduction gear armor, it was mostly ballast. Too far away from the pilot to provide any protection and nose gearboxes weren't normally armored on other planes. Bell had a lot of moving parts to design around, what with larger propellers coming along with possibly a mechanical second stage behind the engine. Those radios could be (were) used to restore balance by moving them from the tail to right behind the pilot given the various balance situations.
I stand by my assertion that the early P-39s (D and F) could have easily been lightened substantially with a resulting performance increase.
Makes one wonder what the British were thinking when they specified a 7850# plane that should have weighed 7100#. I believe they were ordering ground attack planes since they also ordered P-38s without turbos (or handed propellers). Then when the German invasion didn't materialize the British no longer wanted the P-400 or the turboless P-38.
Shortround6
Major General
Basically Larry Bell sold a bill of goods to the French and British (and somewhat to the USSAC.)
The British didn't delete the turbo charger by choice. It wasn't ready for combat service. On the P-38 they wanted interchangeable engines with the P-40s they were buying at the same time. Don't forget the British inherited a bunch of French contracts. They could either accept the French specied aircraft, with minor changes like throttle direction and instruments labeled in english and hope for early delivery or change the specifications a lot and delay delivery for sure. The US didn't even OK the export of turbochargers until after the first orders were placed.
lets also remember that Kelsey crashed the XP-38 less that 2 weeks after it's first flight on Feb 11th 1939 and the next P-38 to fly was a YP-38 on sept 16th 1940 which is after the British have 143 non turbo versions on order and 524 MKIIs with turbos on order. The French and British were ordering paper airplanes with nothing but the manufacturer's estimates to go on.
Larry Bell did test a lightened P-39D, he got the weight down to 6,492lbs but...........
" The same Airacobra was then severely modified by removing the four .30 caliber wing guns and supporting accessoires: all of the gearbox armor plate; the oxygen system; all radio equipment; all instruments except the altimeter, airspeed indicator, engine manifold pressure gage, tachometer, temperature and pressure gages; all tools and fixed equipment not needed essential for flight at 5,000ft altitude; all ballast; and four of the eight self-sealing fuel cells. this saved 1,287lbs"
Page 159 "Cobra: Bell Aircraft Corporation" by Birch Mathews.
We have been over what it took to get a P-400 to meet the British contract requirements in another thread (including the 20 coats of paint sanded between each coat)
Bell promised a plane he could not deliver.
The British didn't delete the turbo charger by choice. It wasn't ready for combat service. On the P-38 they wanted interchangeable engines with the P-40s they were buying at the same time. Don't forget the British inherited a bunch of French contracts. They could either accept the French specied aircraft, with minor changes like throttle direction and instruments labeled in english and hope for early delivery or change the specifications a lot and delay delivery for sure. The US didn't even OK the export of turbochargers until after the first orders were placed.
lets also remember that Kelsey crashed the XP-38 less that 2 weeks after it's first flight on Feb 11th 1939 and the next P-38 to fly was a YP-38 on sept 16th 1940 which is after the British have 143 non turbo versions on order and 524 MKIIs with turbos on order. The French and British were ordering paper airplanes with nothing but the manufacturer's estimates to go on.
Larry Bell did test a lightened P-39D, he got the weight down to 6,492lbs but...........
" The same Airacobra was then severely modified by removing the four .30 caliber wing guns and supporting accessoires: all of the gearbox armor plate; the oxygen system; all radio equipment; all instruments except the altimeter, airspeed indicator, engine manifold pressure gage, tachometer, temperature and pressure gages; all tools and fixed equipment not needed essential for flight at 5,000ft altitude; all ballast; and four of the eight self-sealing fuel cells. this saved 1,287lbs"
Page 159 "Cobra: Bell Aircraft Corporation" by Birch Mathews.
We have been over what it took to get a P-400 to meet the British contract requirements in another thread (including the 20 coats of paint sanded between each coat)
Bell promised a plane he could not deliver.
