Peter Gunn
Master Sergeant
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XP-39 II - The Groundhog Day Thread
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FLYBOYJ
"THE GREAT GAZOO"
Yep - two missions that confirmed the P-39s shortcomings for months to come. You can't "what if" history away, although he did have some complements for the P-39. Should we ignore those based on 2 missions?
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FLYBOYJ
"THE GREAT GAZOO"
Exactly!
P-39 Expert
Non-Expert
I believe the Russians pulled the .30s from the very first P-400s that the Brits gave them. And the IFF radio in the tail cone. Saved about 330lbs. Made them competitive with German planes.
I've always figured a little less than 500rpm out of the synchronized .50s. Works out to about 1 and a half .50s of centerline fire and about 25 seconds firing time. Not optimal but still capable of shooting down another plane.
Not to be picky but those aren't red flags hanging from the .50s charging handles, they ARE the charging handles.
The other red handles below are for the drop tank/bomb release, recharging/reloading the 37mm cannon and charging the wing .30s. Charging the .50s was said to be quite a challenge for a 140lb pilot. Fix was for the ground crew to charge them before the flight. Everything was manual, charging the guns, dropping the tanks/bombs, controlling the coolant and oil temperatures etc.The 37mm cannon fix was to duct more warm air from the cockpit to the gun bay to keep it from freezing at altitude. Most all new airplanes had glitches that had to be corrected.
fubar57
General
Could you provide these documents with references please
P-39 Expert
Non-Expert
No, we should have lightened the plane by removing redundant or unnecessary items to make it climb faster and higher. It was already faster than the Zero. It's either remain way too heavy (as compared to other fighters) and skulk around under 20000' or get lean and climb up to and above where the Japanese are. Just like what the Russians did.
FLYBOYJ
"THE GREAT GAZOO"
"we should have"
The P-38 "should have" had Merlins.
The F4U "should have" been carrier qualified earlier.
The SB2C "should have" been in service a year earlier.
The P-38K "should have" been put into production.
Even with your wishful thinking the P-39 would not have been able to prevail as a front line fighter in the SWP, especially with the P-38 coming on line.
How did you come up with that number?
MODE O.T. ON
The newspaper, which was the main press journal of the Italian Communist Party, says:
Not only I had the dubious privilege of being born and live in the Nation that had the largest Communist Party in the Western world, but also in the Nation with the largest Communist Party in the world after the Soviet Union.
Almost one in three Italians voted until 1989 for the Communist Party and, considering that there were over thirty million voters in Italy, this meant more than ten million Communist votes.
I imagine that it is very difficult for an American or a British to understand how the propaganda of such a strong Communist Party was: everything had been invented in the Soviet Union, from radio to condensed milk and the Party newspaper every day gave the news of some amazing discovery made by some Soviet scientist. The Italians were divided in two: those who believed in it and who would have been ready to swear on what "L'Unità" said, and those who had been vaccinated and instead did not believe a single word of it. In 1989 we saw who History proved right.
Every single statement, or even word, in those times, made by a Communist or a Soviet Military, had to be strictly reviewed by a political staff: so when I read in this Forum that certain statements made by Military of the then Soviet Union are taken as historical truth, I can't help but smile.
MODE O.T. OFF
The newspaper, which was the main press journal of the Italian Communist Party, says:
Eternal glory to the man who most of all did
for the liberation and progress of humanity
and
for the liberation and progress of humanity
and
Stalin's work is immortal!
Long live his invincible cause!
Long live his invincible cause!
Not only I had the dubious privilege of being born and live in the Nation that had the largest Communist Party in the Western world, but also in the Nation with the largest Communist Party in the world after the Soviet Union.
Almost one in three Italians voted until 1989 for the Communist Party and, considering that there were over thirty million voters in Italy, this meant more than ten million Communist votes.
I imagine that it is very difficult for an American or a British to understand how the propaganda of such a strong Communist Party was: everything had been invented in the Soviet Union, from radio to condensed milk and the Party newspaper every day gave the news of some amazing discovery made by some Soviet scientist. The Italians were divided in two: those who believed in it and who would have been ready to swear on what "L'Unità" said, and those who had been vaccinated and instead did not believe a single word of it. In 1989 we saw who History proved right.
Every single statement, or even word, in those times, made by a Communist or a Soviet Military, had to be strictly reviewed by a political staff: so when I read in this Forum that certain statements made by Military of the then Soviet Union are taken as historical truth, I can't help but smile.
MODE O.T. OFF
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
And his Mustang's wheels were bright red, too!
In regards to technical aptitude by various populations, we have to consider the circumstances of each population leading up to the late 30's.
In the urban areas (pick any nation), people didn't need technical savvy to go about their daily lives - they could walk to their destination, catch a tram, trolley, bus or train.
However, outside of urban areas is where things change. Prior to WWII, a great deal of populations still lived in the countryside and were farmers, fishermen, ranchers, loggers, miners and so on.
In the case of the U.S., mass production of cars, tractors, trucks and evennutility engines coupled with readily available (and inexpensive) fuel saw widespread use where many other nation's were still using teams as a primary means.
Americans could even order a Ford or Allstate (ford licensed) car through the Sears catalogue - which was delivered in a crate and required assembly (and you thought IKEA was the first!). Additionally, these car kits could be modified to operate saw mills, irrigation pumps and so on (the car would be partially assembled, raised off the ground and a leather belt ran the apperatus from a special "wheel" mounted to the rear axle).
So in the end, it wasn't that Americans were smarter than Soviets, British, Germans or anyone else, it's the abundance of available machines that put them in that position.
buffnut453
Captain
You state that "Prior to WWII, a great deal of populations still lived in the countryside and were farmers, fishermen, ranchers, loggers, miners and so on." That may have been true in the US but it was NOT true in the UK. Most population lived in cities and large towns, and had done since the mid-1800s. Only around 10 percent of British workers were involved in agriculture in 1939.
The urban areas were heavily industrialised. People may not have needed a car to get to work but they used and maintained machinery in every factory. To suggest that owning a car was somehow superior to being a trained technician maintaining milling machines, steam hammers, cotton mills, or any other number of the thousands of machines that came about in the 200 years following the industrial revolution is ridiculous.
It's precisely this sort of Tom Sawyer/Huck Finn-goes-to-war myth that drives me bonkers. If the greater part of a country's workforce is urbanised and working in manufacturing (as it was in the UK), are they less technically savvy than a farmer with a Model T? Almost all manufacturing in the 1930s still required human skill and ingenuity...but, of course, that doesn't fit the American mythology and so it gets ignored.
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P-39 Expert
Non-Expert
Not that I'm writing a doctoral thesis, but that is from Vees for Victory, book about the Allison V-1710.
P-39 Expert
Non-Expert
The Merlin P-38 would have taken how long to bring to production? A year maybe?
The F4U probably should have.
The SB2C I have no idea, but the Navy kept changing their requirements.
P-38K would have taken how long to bring to production, and how many P-38J/L would have been delayed/cancelled?
Lighter P-39 would have taken about 3 hours of maintenance crew's time at a combat base. Remove the wing .30s and their mounts, chargers, heaters and ammo boxes, and the nose armor plate. While you're at it remove the IFF radio and save another 130lbs. Still have the voice radio.
The 1.2feet/minute climb per pound of weight saved comes from wwiiaircraftperformance.org. Compare the climb rates of the P-39D and the P-39C at their different weights. C climbed 1000fpm faster than the D and weighed 836lbs less, making each pound of weight improve climb by 1.2fpm. I know the C model did not have self sealing tanks and armor plate but it had the exact same engine, propeller and aerodynamics as the D model. Only difference in performance was the weight.
Hello XBe02Drvr,
From the first combat report with P-39Ds, The Zeros encountered were reported as having larger cowls.
That factor is quite noteworthy. If ever there was a "lead sled" version of the A6M fighter, they had just encountered it.
The reasoning is this:
The report only notes a cowl change and not a clipped and squared wing which meant that it was not the A6M3 Model 32 (AKA "Hap" / "Hamp"). It would have been the later A6M3 Model 22 which was one of the heaviest versions because of increased fuel capacity until the very late war versions got even heavier.
At low altitude, power is slightly greater. (Surprisingly little.) but the combination of significantly more weight and different propeller pitch ranges probably made this a little less quick in acceleration and definitely less maneuverable.
The Japanese note in their manual that at medium altitudes and below, the Mark I fighter (A6M2) is superior to the Mark II (A6M3 / A6M5) but above 8000 Meters, the performance of the Mark II becomes progressively better.
Maximum speed under "Normal Power" was substantially better in Mark II but actual maximum speed for the type is very hard to pin down. Sources don't seem to agree. My best guess is that the difference was no more than a 5 MPH advantage for the A6M3.
Neither combat described was above 8000 Meters.
From a performance standpoint, the P-39F is identical to the P-39D with the same V-1710-35 but just with an Aeroproducts propeller with slightly different pitch ranges.
- Ivan.
P-39 Expert
Non-Expert
A6M3 was not available until October 1942, this was in May.
Hello P-39 Expert,
I am just going by what the combat report says. I presume the pilots were reporting accurately.
The Japanese had a habit of fielding prototypes before the production models were finalized, so perhaps that is what happened here. I am a bit suspicious of that theory because the prototypes were not usually available in great numbers.
- Ivan.
P-39 Expert
Non-Expert
As we have discussed before, the engine compartment of the P-39 without the auxiliary stage supercharger was exactly the same size as the engine compartment of the later P-63 with the auxiliary stage supercharger. Exactly the same distance from the front of the engine section to the bulkhead at the rear. See the attached drawings. Now that is either an amazing coincidence or the P-39 was designed from the beginning to accommodate the auxiliary stage supercharger. All the Allisons had long lead/development periods. Bell knew that a two stage engine was coming, just like they new the -63 and the -85 were coming. Just like they knew larger, heavier propellers were coming. All designed in from the beginning.
That story about the P-39E being two feet longer is correct, but it was the tail cone section that was lengthened, not the engine compartment. That was the same as any P-39. Just another story handed down for the last 75 years that is taken as fact, like the Russians used the P-39 for ground attack, the 37mm cannon had a looping trajectory, the Allison didn't have a supercharger etc. Almost all of them wrong.
Attachments
Hello P-39 Expert,
The P-39M was one of the Mid Production versions, about the same as the P-39N.
The engine was the V-1710-83 with significantly better altitude performance than the earlier models with the V-1710-35 and V-1710-63. It carried a bigger propeller (11 feet 1 inch) with different reduction gearing because the engine had the altitude performance to use it. Earlier models had a 10 feet 4 1/2 inch propeller.
What could be done with this engine is not indicative of what would work with earlier engines.
What change in nose cannons made a difference of 140 pounds?
- Ivan.
It has to be said that in Italy, expecially in the South, until 1960, practically all the farming was done with carts like these.
I remember perfectly well, when I was a young lad, the clinging of the bells of the oxen going to work at sunrise, when I spent my summer holidays in a tiny village of the inner part of Sardinia, and also remember that in Sicily, same period, fishermen went to sea by oar and sail. (Not joking...)
For the average Italian, outside public transport, until early-mid 50s, when Piaggio started the production of the famous "Vespa"
the only private transport available was the bicycle, and to have a car privately owned by practically every family we had to wait until early 60s, with the Fiat 600.
That, of course, does not mean that Italians could not master mechanics
but numbers were not at all comparable with those of U.S.
Wehrmacht used mainly horse drawn carts in the lands of Russia but, for propaganda purposes, just trucks appeared in the photos officially released.
buffnut453
Captain
My point is that applying the American situation to other countries is inappropriate. Equally, applying the situation in the UK to that in Italy is equally futile. The industrial revolution occurred at different times at different regions. Equally, levels of technical awareness varied greatly...but to suggest the US had greater technical savvy because farmers had Model Ts is taking things much too far (IMHO).
Hello buffnut453,
You have a point. Ford Model Ts are crap. Much more likely they were Model As or something later.
- Ivan.
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