Did it improve the type's performance at all?
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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Did it improve the type's performance at all?
Shortround6
Major General
Yes, The list is upthread somewhere but here it is again.
This was serial number 41-38291, a P-39D-1. first in standard configuration and then modified.
Removal of the four wing guns and supporting accessories, all of the gear box armor plate, the oxygen system, all radio equipment, all instruments except the altimeter, the airspeed indicator, engine manifold pressure gage, tachometer, temperature and pressure gauges; all tools and fixed equipment not essential for flight at 5,000ft, all ballast and four of the eight self-sealing fuel cells. This saved 1287lbs. On page 159 of "Cobra!" by Birch Mathews.
The only performance figures given are for time to 5,000ft, radius of turn and stalling speed. Time to climb 5,000ft dropped from 2 min 34 sec to 1 min 54 sec.
This was serial number 41-38291, a P-39D-1. first in standard configuration and then modified.
Removal of the four wing guns and supporting accessories, all of the gear box armor plate, the oxygen system, all radio equipment, all instruments except the altimeter, the airspeed indicator, engine manifold pressure gage, tachometer, temperature and pressure gauges; all tools and fixed equipment not essential for flight at 5,000ft, all ballast and four of the eight self-sealing fuel cells. This saved 1287lbs. On page 159 of "Cobra!" by Birch Mathews.
The only performance figures given are for time to 5,000ft, radius of turn and stalling speed. Time to climb 5,000ft dropped from 2 min 34 sec to 1 min 54 sec.
Thanks for that (I don't wanna go searching through the entire thread). So, what was learned from it? Did these changes lead to improvements that were applied to the type on the production line and in service?
buffnut453
Captain
Methinks it'll be a long wait. Direct questions haven't been answered with anything other than opinion....and even then, they're ignored more than answered.
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buffnut453
Captain
And it was also specified in the Bell Model 13, P-39C which suggests the British did NOT specify the gas heater. This has been raised several times but you keep ignoring this fact.
If the gas heater was useless, then it's down to Bell who included it as standard equipment in the Model 13. The British would simply have ensured cockpit heating was provided...it was down to Bell to ensure the heating system worked correctly.
Glider
Captain
I should have ended it ' We await your response with interest, but not much anticipation
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
It was a great post, but I would have concluded with:
"I don't expect an informed reply."
But then again, I'm not known for my diplomacy...
There was an operational radar since late March 1942 at Port Moresby. It performed poorly, mainly because inadequate training of its staff, but the fact that there was an operational radar meant that a/c operating in the area needed IFF. More info in this message by late Parsifal SHOULD the P39 have been able to handle the Zero? Was it training or performance?
P-39 Expert
Non-Expert
This was a one-off example. I have shown numerous times how a properly equipped 1942 P-39 would have weighed 7150 lbs.
Bell did show how P-39 weight could be reduced by 1000lbs in May 1943. Details were not provided in the book.
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P-39 Expert
Non-Expert
One last time, no 30calMGs were used on any AAF/USN P-38E/F/G/H/J/L, P-40D/E/FK/L/M/N, P-47, P-51A/B/C/D, F4F3/4, F4U1/4, F6F, F7F, F8F. None. 100,000 planes, how many used 30cals? None. Except the P-39.
Exactly how many P-40B/Cs actually saw combat with the AAF? How many P-35s? A very insignificant amount.
Exactly how many P-40B/Cs actually saw combat with the AAF? How many P-35s? A very insignificant amount.
So they used something heavier? So what is your point? How can you claim the British wanting things that increased weight was perfidy when the US was doing exactly the same. BTW you are doing that thing again where your "never" becomes not "often". Of those 100,000 the P-39s used by the USA as a weapon was also an insignificant amount.
And how does that look against a P-38, P-47, Mustang I, Spitfire IX, Typhoon? Would you cross the Channel to take on an Fw 190 with it?
I would say it would be perfectly reasonable. The Mustang I defied what was known when the Spitfire and Hurricane were designed and ordered.
The UK had ordered its first jet in 1939 and started testing it in April 1941, it flew in May 1941 doing 350MPH on its first flight which completely defied what was known by most. With advances in aerodynamics, a revolutionary mid engine design, much lighter than a Mustang I could easily be believed to be faster and close to 400MPH.
Your original claim was "Yes the British were still using 30calMGs after the BoB, but the AAF WAS NOT." Again, when shown that you were wrong, your changed your claim, as you always do. 1/5 of USAAC fighters in Philippines on 7 Dec 1941 were P-40Bs (18) and 1/5 P-35s (18), and there were definitely P-40Bs on Oahu.
And most of the great aces of the WWII acknowledged that surest way to make a kill was open fire at close range, 200 yds was a good range to make a kill in early 40s. And on effectiveness of the .303, on 6 Jan 1940 Sarvanto shot down six Soviet DB-3Fs, these had armour and self-sealing fuel tanks, in five minutes while flying in Fokker D.XXI, 4 7.7 mm Brownings. And those six were not only claims, all six wrecks were found and nowadays we know from Russian documents that only one of 8 DB-3Fs of that formation returned and 7 were shot down the 7th by Sovelius. Sarvanto was exceptionally good shot and as Finns were trained opened fire at close range and probably all or three of his mgs were loaded with Italian APIs, the 4th might have been loaded with trackers. The downside of the close range tactic was that Sarvanto's plane was hit 23 times during the engagemant.
Shortround6
Major General
Strangely enough the British wound up using a convergence distance of 250 yds for their .303s, 50 yds beyond the effective range?
Earlier they had set up the guns to converge at 350yds
The American .30-06 was one of the two most powerful rifle caliber machine gun cartridges used in WW II. It was around 18% more powerful than the British .303 or the Japanese 7.7mm.
It had about 10% more velocity for shorter time of flight.
Not a lot but to say that the US .30 was useless when other countries achieved so much with weaker cartridges and slower firing/rate of fire guns (Japanese) seems to fly in the face of common sense.
There was also a supply issue, in 1940-41-42 there weren't enough .50 cal guns for everybody that wanted them. Remember that supply allocations were often made months if not over a year before actual construction/deployment.
A number of US bombers went into service in 1940-41 and 42 using at least a few .30 cal guns.
The US may very well have been specifying too many guns or too heavy a weight of guns/ammo for good performing aircraft. The P-40D & E were a classic example.
However in 1940 NOBODY had much experience with the US .50 cal in combat.
First combat Victory by a U.S. built fighter in the ETO was by a Martlet on Christmas day 1940, well after the daylight portion of the BoB was over.
Any and all advantages of the .50 cal gun and ammo were purely theoretical up to that point, except, perhaps for a few .50 cal guns that might have made it to China?
Earlier they had set up the guns to converge at 350yds
The American .30-06 was one of the two most powerful rifle caliber machine gun cartridges used in WW II. It was around 18% more powerful than the British .303 or the Japanese 7.7mm.
It had about 10% more velocity for shorter time of flight.
Not a lot but to say that the US .30 was useless when other countries achieved so much with weaker cartridges and slower firing/rate of fire guns (Japanese) seems to fly in the face of common sense.
There was also a supply issue, in 1940-41-42 there weren't enough .50 cal guns for everybody that wanted them. Remember that supply allocations were often made months if not over a year before actual construction/deployment.
A number of US bombers went into service in 1940-41 and 42 using at least a few .30 cal guns.
The US may very well have been specifying too many guns or too heavy a weight of guns/ammo for good performing aircraft. The P-40D & E were a classic example.
However in 1940 NOBODY had much experience with the US .50 cal in combat.
First combat Victory by a U.S. built fighter in the ETO was by a Martlet on Christmas day 1940, well after the daylight portion of the BoB was over.
Any and all advantages of the .50 cal gun and ammo were purely theoretical up to that point, except, perhaps for a few .50 cal guns that might have made it to China?
Peter Gunn
Master Sergeant
Uh... what?
I see you cherry pick around the P-40 and P-51 marques that were armed with .30's which surprises me not in the least.
Not to mention that the original F4U design used .30's as did the F2A.
As for the Airacobra, keep the wing guns, ditch the dumb cannon and replace it and the two nose guns with .30's and you'd have a 7 gun fighter with all the same caliber weapons (read same trajectory/ballistics) and a sh!t load of ammunition and turn it loose against the IJN/IJA.
And on another note, to say that IFF isn't needed is down.right.stupid.
I'm pretty sure Bifff (with 3 'f's) has already given you the reason you don't want to delete the IFF, but hey, why listen to an experienced fighter pilot amiright? Ah yes, he didn't fly P-39's and he's just Joe Pilot anyway so we can discount his opine on that.
Shortround6
Major General
Lets try again.
P-39K at 6663lbs tactical empty from the weight chart in the manual.
Take out 100lbs worth of .30 cal guns or even add another 20lbs for "extras"
take out 100lbs of armor. leaving you with what the P-39C had.
take out 45lbs for IFF, that seems to be the highest figure.
you are down to just under 6400lbs
now add 720lbs of fuel.
OOPS, 7120lbs with NO AMMO.
That is a 1942 P-39.
No P-39M or N made it into combat in 1942.
You want to argue about P-40B&Cs and when they were used?
You have to take it on the other end.
I wonder why?
Again, look at the P-40N-1 to see what they did. And they used aluminum radiators/oil coolers and magnesium wheels in addition to restricting armament and ammo.
That ONE OFF saved 1287lbs. There simply isn't enough stuff to take back out of the plane to save 1000lbs without severely compromising operational use.
All but a few hundred pounds went back into the P-40N-1s once they got to the operational squadrons. Stupid squadron commanders?
Gents,
FYI this round and round regarding the P39 by the Expert has been going on since March, 2018. That's 3 years, 4 months. If this was a war front, I would describe it as a WW1 trench front, concertina wire tacked to fence posts, blown apart in places, trees with no leaves, brick remains of buildings, destroyed in the melee with scattered remains of soldiers killed during gas attacks. And there is absolutely nothing to show for the efforts. Distance gained, zero.
Personally I have learned a ton about the P39 I didn't know, and some of you have done exquisite work in unraveling the Experts "information" either by timeline or context. It's much appreciated by myself, and I believe others.
Good luck.
Biff
FYI this round and round regarding the P39 by the Expert has been going on since March, 2018. That's 3 years, 4 months. If this was a war front, I would describe it as a WW1 trench front, concertina wire tacked to fence posts, blown apart in places, trees with no leaves, brick remains of buildings, destroyed in the melee with scattered remains of soldiers killed during gas attacks. And there is absolutely nothing to show for the efforts. Distance gained, zero.
Personally I have learned a ton about the P39 I didn't know, and some of you have done exquisite work in unraveling the Experts "information" either by timeline or context. It's much appreciated by myself, and I believe others.
Good luck.
Biff
Thumpalumpacus
Major
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
Thanks! I know just how to do it. Hello buffnut453. Calling buffnut453!
