The P39 had an unspectacular record against Japanese fighters. Was it an issue of pilot training against an unfamilier enemy aircraft? Or was the performance of the Zero the P39's undoing? The P39 had a 30 or 40 mph speed advantage over the Zero, about the same as a Spitfire, so why couldn't the P39 use this speed and dive advantage to beat the Zero like the Hellcat did?
SHOULD the P39 have been able to handle the Zero? Was it training or performance?
- Thread starter pinsog
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varsity078740
Airman
- 47
- Aug 30, 2006
The Hellcat had a 2,000 HP two stage, two speed engine that provided superior performance over the Zero at all altitudes despite weighing much more. What ever speed advantage the P-39 had over the Zero was at low altitude and degraded rapidly at altitudes greater than 12,000 ft. which was the rated altitude for the single speed, single stage Allison.
Duane
Duane
davebender
1st Lieutenant
Engine power per se isn't what matters. You want a high power to weight ratio. P-39 power to weight ratio is similiar to F6F.
Data from Wikipedia.
.....F6F5. 2,000hp. 12,598 lbs loaded weight. 6.3 lbs per hp.
.....P39Q. 1,200hp. 7,379 lbs loaded weight. 6.15 lbs per hp.
Data from Wikipedia.
.....F6F5. 2,000hp. 12,598 lbs loaded weight. 6.3 lbs per hp.
.....P39Q. 1,200hp. 7,379 lbs loaded weight. 6.15 lbs per hp.
The P-39 (among many Allied airplanes) have had several issues that were hampering it's better score vs. Zero.
The crucial thing could easily be the lack of dependable early warning systems in areas where the P-39s were operating during 1942. As seen in ww2 in all theaters, the fighters, no matter how good, need sufficient time to warm-up, take off and climb to the suitable altitude.
Next thing would be the pilot's tactics experience - P-39 should flatly lose the vs. Zero in turning fight, and Zero's pilots were the best in the world in 1942.
Then we go to the engine limitations: the single speed V-1710 was, during the 1st half of the war, a dog above 15000 ft. The airframe issue would be the loopsided layout of the engine intake, much reducing the ram effect. That should steal couple of thousands HP/feet from the already low engine power/altitude. The Japanese bombing runs were conducted at higher altitudes, and their Zeros have had two-speed superchargers, so the Zeros would be the ones to dive at P-39s, not vice versa. Another airframe issue would be the low fuel quantity, giving the P-39 pilot two uneasy choices:
- drop the tank and engage what is close (and that might be the Zero coming to get him), leaving it without fuel to chase speedy Japanese bombers
- leave the drop tank on, and risk to be shot down since one is slow unviedly with the DT
Having the DT attached also lowers the rate of climb, not a good thing if the bombers Zeros are close.
The crucial thing could easily be the lack of dependable early warning systems in areas where the P-39s were operating during 1942. As seen in ww2 in all theaters, the fighters, no matter how good, need sufficient time to warm-up, take off and climb to the suitable altitude.
Next thing would be the pilot's tactics experience - P-39 should flatly lose the vs. Zero in turning fight, and Zero's pilots were the best in the world in 1942.
Then we go to the engine limitations: the single speed V-1710 was, during the 1st half of the war, a dog above 15000 ft. The airframe issue would be the loopsided layout of the engine intake, much reducing the ram effect. That should steal couple of thousands HP/feet from the already low engine power/altitude. The Japanese bombing runs were conducted at higher altitudes, and their Zeros have had two-speed superchargers, so the Zeros would be the ones to dive at P-39s, not vice versa. Another airframe issue would be the low fuel quantity, giving the P-39 pilot two uneasy choices:
- drop the tank and engage what is close (and that might be the Zero coming to get him), leaving it without fuel to chase speedy Japanese bombers
- leave the drop tank on, and risk to be shot down since one is slow unviedly with the DT
Having the DT attached also lowers the rate of climb, not a good thing if the bombers Zeros are close.
CobberKane
Banned
- 706
- Apr 4, 2012
The P-39s altitude performance sucked. At Guadalcanal the Japanese pilots were so used to seeing the P-39s at a serious height disadvantage they thought they were being used as bait to give the higher flying Wildcats a free shot.
davebender
1st Lieutenant
Not every fighter aircraft needs to be a high altitude interceptor.
What about below 10,000 feet where A-20s and B-25s are performing low altitude attacks?
What about below 10,000 feet where A-20s and B-25s are performing low altitude attacks?
Francis marliere
Airman
- 72
- Aug 9, 2004
As far as I know, P-39 37 mm cannon almost always jammed (according to pilots), and machineguns frequently did. A plane can't be succesfull if it can't fire ...
At Guadalcanal, the early planes were P-400 (export version with 20 mm cannon) which used British oxygen bottles which were not available there. Hence the planes were limited to low altitude and performed ground attack missions.
At Guadalcanal, the early planes were P-400 (export version with 20 mm cannon) which used British oxygen bottles which were not available there. Hence the planes were limited to low altitude and performed ground attack missions.
Pinsog, I'd have to throw that off on the aircraft. The F4Fs had trouble, too. Everything else being equal, they were outclassed. Of course, disclaimer, everything else is never equal.
- Thread starter
- #10
I agree the P39 had flaws, but it was much faster then the Zero and could easily out dive the Zero. The F4F had nothing on the Zero except being tougher and yet it fought the Zero to about a draw while the P39 didn't do as well. How can that be explained?
davebender
1st Lieutenant
P-40 was faster then Japanese fighter aircraft used in Philippine invasion and FEAF had over 100 yet they accomplished little. I suspect early war P-39s had the same problem - poor U.S. Army Air Corps training and leadership.
FLYBOYJ
"THE GREAT GAZOO"
"You don't dig a hole with a rake."
I think the biggest problem with the P-39 was its misuse by the USAAF. It was pretty obvious that about 15,000 feet the aircraft would be useless, but given its handicap it performed well. Go look at the Air Force Historical Research site and check out the claims/ losses during early and mid 1942. The P-39 (and P-40) were scoring about a 1:1/ 1:2 against the Japanese through out the Pacific. There was only one P-39 ace, Lt. William Fiedler Jr., but look how many P-38 aces achieved their first kills in the P-39.
I think the biggest problem with the P-39 was its misuse by the USAAF. It was pretty obvious that about 15,000 feet the aircraft would be useless, but given its handicap it performed well. Go look at the Air Force Historical Research site and check out the claims/ losses during early and mid 1942. The P-39 (and P-40) were scoring about a 1:1/ 1:2 against the Japanese through out the Pacific. There was only one P-39 ace, Lt. William Fiedler Jr., but look how many P-38 aces achieved their first kills in the P-39.
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- Thread starter
- #13
Would you be suggesting that the reputation of the P39 vs the Zero has been unfairly maligned over the years?
How many US or other pilots had good things to say about the P39 vs the Zero?
FLYBOYJ
"THE GREAT GAZOO"
Yes - and in many cases the F4F as well.
AFAIK not many, but then again, many P-39 drivers wound up in the P-38, so of course the P-39 is going to be scorned.
There have been several discussions in this forum on how to build a 'better' P-39.
The P-39C had two 50 cal and two 30 cal machine guns firing syncronized thru the propeller, but in the P-39D and later models the nose 30 cals were removed to make room for additional 37mm cannon ammo. Hindsight says keeping the P-39C armament but replacing the 37 mm with a hub mounted 50 cal would have been a better arrangement against the Japanese. Even better, trade the two syncronized 30 cals for another syncronized 50caliber (one thru thru the prop hub and a new total of three syncronized). Then use the space in the wing formerly devoted to ammunition storage for additional internal fuel capacity.
The P-39C had two 50 cal and two 30 cal machine guns firing syncronized thru the propeller, but in the P-39D and later models the nose 30 cals were removed to make room for additional 37mm cannon ammo. Hindsight says keeping the P-39C armament but replacing the 37 mm with a hub mounted 50 cal would have been a better arrangement against the Japanese. Even better, trade the two syncronized 30 cals for another syncronized 50caliber (one thru thru the prop hub and a new total of three syncronized). Then use the space in the wing formerly devoted to ammunition storage for additional internal fuel capacity.
- Thread starter
- #16
Or go with 2 50's, a 20mm through the hub, wet wings with no guns and hopefully a bit of weight savings.
- Thread starter
- #17
I would like to see a head to head comparison of the F4F vs the P39 and see how they matched up with each other. My guess is the P39 would win everything but turning. Your thoughts?
FLYBOYJ
"THE GREAT GAZOO"
Agree - providing this match up was under 10/ 15,000'. Then the F4F would take all.
- Thread starter
- #19
Best guess at what altitude they would be dead even at? Wouldn't the P39 be faster than an F4F even at 20,000 feet?
Three comments. First the mixed armament thing, trying to deal with two different trajectories when deflection shooting. That is why I suggested an all 50 cal armament package. Second, history tells us the most US versions of the 20mm Hispano cannon had almost as much trouble with jams/un-reliability early in the war as the 37mm. Another point for staying with just Browning 50 cal guns. Finally, as far as I know, during WW2 'wet wings' implied unprotected fuel tanks. I am suggesting adding self-sealing rubber bag tanks as per other American fighters.
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