P-39 Expert
Non-Expert
None of the Allison powered fighters, nor the P-47 nor the Spitfire V met hot day cooling standards.
Groundhog Thread Part Deux - P-39 Fantasy and Fetish - The Never Ending Story (Mods take no responsibility for head against wall injuries sustained)
- Thread starter greybeard
- Start date
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MiTasol
1st Lieutenant
While I also consider the numbers suspect there is absolutely no doubt that if there are two identical aircraft with different weights the lightest will climb fastest.
Another factor is that the Q models had large nostrils for the fuselage 50 cals and those will have created drag and probably turbulence, both of which affect (reduce) performance.
A third factor is how well fitted the belly armour was. Having that 1/2 inch thick alloy plate hanging a mm low at the front would create a significant increase in drag
CORSNING
Tech Sergeant
Great information guys. Thank you all.
P-39 Expert
Non-Expert
There was actually a second climb test on that same P-39N #4400 about a month later on November 24 to record WEP climb which was not used on the original P-39N climb test. This climb test showed the expected increase in climb below critical altitude but the climb rate at 15000' (critical altitude for climb) was 3230fpm or only 110fpm lower than the previous test at the same 1060HP. Weight was only 27# more. The climb rate at 15000' was virtually the same on both tests, indicating neither test was a fluke and the plane climbed as advertised. Climbed faster than just about anything in '43 except a Spitfire IX.
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Kevin J
Banned
Maybe this can clear up the debate on just how good the P-39 really was when used correctly. You'll need to run this in google chrome for it to automatically translate.Great information guys. Thank you all.
P-39 Аэрокобра на советско-германском фронте
Shortround6
Major General
It is interesting but flawed, it doesn't really say how the planes were were used (tactics or combat situation) and relies on the rather dubious method of comparing the scores of the top aces. I am not trying to get into an argument about claiming or over claiming or anything like that.
The method is dubious because it fails to take into account the number of missions flown by the pilots of each type and number of times each pilot was actually engaged in combat. As an extreme example we have Eric Hartman who (according to wiki) He "flew 1,404 combat missions and participated in aerial combat on 825 separate occasions." to get is 352 victories.
This article does not tell us how many combat missions the various pilots (of several air forces) flew or how many of those missions resulted in actual combat.
The US in particular tended to rotate pilots out of combat after a fixed number of missions (although many extended their tours voluntarily or signed up up for a whole new tour, same with many British pilots, including the commonwealth).
So if you have a Russian pilot who flew plane A on 250 missions and engaged in combat (fired guns?) 175 times and claimed 50 victories how does that prove that Plane A was better than Plane B that was flown by An american pilot 120 times and fired it's guns 75 times and shot down 30 planes? (made up numbers)
Please note I am not trying to take anything away for Hartman or any of the pilots listed in the article. In many cases it was a testament to luck, skill and day in day out courage simply to survive 100 mission let alone several hundred. Shooting down substantial quantities of enemy aircraft is a whole different story.
The method is dubious because it fails to take into account the number of missions flown by the pilots of each type and number of times each pilot was actually engaged in combat. As an extreme example we have Eric Hartman who (according to wiki) He "flew 1,404 combat missions and participated in aerial combat on 825 separate occasions." to get is 352 victories.
This article does not tell us how many combat missions the various pilots (of several air forces) flew or how many of those missions resulted in actual combat.
The US in particular tended to rotate pilots out of combat after a fixed number of missions (although many extended their tours voluntarily or signed up up for a whole new tour, same with many British pilots, including the commonwealth).
So if you have a Russian pilot who flew plane A on 250 missions and engaged in combat (fired guns?) 175 times and claimed 50 victories how does that prove that Plane A was better than Plane B that was flown by An american pilot 120 times and fired it's guns 75 times and shot down 30 planes? (made up numbers)
Please note I am not trying to take anything away for Hartman or any of the pilots listed in the article. In many cases it was a testament to luck, skill and day in day out courage simply to survive 100 mission let alone several hundred. Shooting down substantial quantities of enemy aircraft is a whole different story.
P-39 Expert
Non-Expert
Am I going crazy or did that article repeat itself w few times in the body of text?
Shortround6
Major General
you are not crazy. More than few times.
P-39 Expert
Non-Expert
But, I could still be crazy.
Kevin J
Banned
You might like to try going through the entire website. There's a lot more detail in the P-40 section. IIRC there's a section on fighter tactics somewhere but its a long while ago that I found all this. IIRC, the Cobras used to fly in four pairs of two separated by 1000 feet of height with only two assigned the task of shooters, the rest acting as cover. It was called group area fighting tactics.
Thanks for the link.
Google Translate seems to have its problems in a few areas, but I can read enough of the original Russian to tell what was going on.
The second page was much more interesting than the first because it showed that the Soviets also ran into their share of problems and even lost quite a few experienced pilots because of the P-39's CoG and structural problems.
It appears to me that the P-39 appeared to do well in Soviet service because their standards tended to be much lower than those of the Western Allies.
- Ivan.
CORSNING
Tech Sergeant
Ivan, in a way you are correct. The Russians did not have the natural resources
available to them as many other nations had. Most of there aircraft exteriors
were wood and the engines available to them early in the war were very limited
in power.
If by lower you mean geared to the lower altitudes then you are absolutely
correct. If you mean their expectation of what they wanted out of there front
line fighters then I would reply, " No, I do not believe any of the warring nations
wished to settle for less than the nation's aircraft they had to oppose."
Hello Corsning,
I am not sure I can agree with your summary of the Soviet Union's resources of the time.
I believe most of their problems before the war was that although there WERE plenty of resources, there wasn't the industrial and educational background in the general population to support many industries.
Regarding low power aero engines, the United States wasn't doing much better at the time with its Allison as compared to the Soviet Klimov and Mikulin designs. None were that high powered initially.
Regarding radials, there are a lot more variation but I believe the general philosophy was way different and I don't believe I am knowledgeable to do more than speculate there.
Regarding low altitude versus high altitude supercharging, just keep in mind that the pre-war United States wasn't really doing any better. Along with a multi-stage supercharger that is needed for good altitude performance, there typically needs to be an intercooler and the two add a significant weight penalty and cost performance at lower altitudes. Neither is needed for aircraft that are basically used to support ground forces.
My actual comment about lower standards was more about the quality that the Soviets were willing to accept and produce. Many of their aircraft had serious problems and dangerous handling characteristics. The wooden aircraft structures you mentioned earlier had quite a few failures due to manufacturing issues. Their early fighters were hardly competitive and some had stability problems or were seriously underpowered. I don't think (slightly) inferior quality bothered them much because "Quantity has a quality all its own."
Basically, the Soviets were very good at building for war where peasant soldiers and pilots are cheap. They start with a pretty good design and build it to a mediocre standard and let the numbers overwhelm the opposition. Sooner or later some of these soldiers and pilots gain the experience to be very dangerous adversaries.
By this standard in comparison to an early LaGG fighter, an Airacobra looks pretty good despite CoG issues and structural failures.
- Ivan.
Someone might have addressed this already, but I believe All the folks at NII VVS were doing was converting from TAS to IAS.
Try a couple of the conversions. The numbers aren't too far off for TAS converted to IAS.
- Ivan.
CORSNING
Tech Sergeant
Back on topic, I agree that the P-39 (any version) was never a first
class fighter. It did help the US to hold the line in the Pacific in 1941,
1942 and early 1943. It was exactly what the Russians needed in
1942/1943.
I have a lot more to add but the Mrs. told me to get my...self in the
shower so that we can kick back for the evening.
See you guys tomorrow. As Ray (Trailer Park Boys) puts it the best,
"That's the way she goes boys, that's the way she goes."
Love you guys, Jeff
class fighter. It did help the US to hold the line in the Pacific in 1941,
1942 and early 1943. It was exactly what the Russians needed in
1942/1943.
I have a lot more to add but the Mrs. told me to get my...self in the
shower so that we can kick back for the evening.
See you guys tomorrow. As Ray (Trailer Park Boys) puts it the best,
"That's the way she goes boys, that's the way she goes."
Love you guys
, JeffI am glad that Driver Education business got split off into its own thread.
I am not entirely certain this is on topic either, but here goes:
The Russian article also mentioned that the reduction in fuel capacity with the P-39N was requested by the Russians.
This is an interesting thing considering that the fuel load was only 120 Gallons before being reduced.
The already short range apparently didn't make a difference because the airfields were so close to the front lines and pilots were typically flying up to 3-4 missions in a day.
From that perspective, 1400 missions by Hartmann does not sound so extreme.
- Ivan.
I am not entirely certain this is on topic either, but here goes:
The Russian article also mentioned that the reduction in fuel capacity with the P-39N was requested by the Russians.
This is an interesting thing considering that the fuel load was only 120 Gallons before being reduced.
The already short range apparently didn't make a difference because the airfields were so close to the front lines and pilots were typically flying up to 3-4 missions in a day.
From that perspective, 1400 missions by Hartmann does not sound so extreme.
- Ivan.
P-39 Expert
Non-Expert
P-39 actually held lots of fuel when compared to European planes. More than the Spitfire and Me109 and more than a Fw190 based on gallons to displacement.
Incredibly the Russians didn't need that much gas for their missions and recommended the reduction. AAF probably went along with it since the primary role for the AAF in '43 was training and reduced fuel dovetailed with that mission.
Incredibly the Russians didn't need that much gas for their missions and recommended the reduction. AAF probably went along with it since the primary role for the AAF in '43 was training and reduced fuel dovetailed with that mission.
CORSNING
Tech Sergeant
The P-39N and P-39Q-1 came from the factory with the capacity
to carry 87 US gallons of internal fuel. This gave the P-39s a practical
range of 360 mls. at 214 mph.
to carry 87 US gallons of internal fuel. This gave the P-39s a practical
range of 360 mls. at 214 mph.
P-39 Expert
Non-Expert
Reduced from the original 120 gal. on the first 167 P-39Ns.
Gallons per displacement don't tell us a lot, if anything. Gallons per power might be a better metrics?
However - Re.2001, 2005 and G.55 carried more fuel than the P-39, especially than the versions with reduced fuel.
