P-38 production blocks mods/service

[SgtPappy]

I got my hands on the P-38H/J/L/F-5B Manual and I was wondering at which point Lockheed added certain components.
The document only states that 'early airplanes have...etc.' and 'late airplanes are fitted with... etc.'

For example, I'd like to know on which production block the heating ducted from both engines was implemented. The document states that 'early airplanes' have heat ducted from the right engine and 'late airplanes' had heat ducted from both.

Some sources say that the P-38J was the aircraft that 'improved' the heating and the L fixed it.
1) How bad was this heating in versions prior to the J (or the suspected version with proper heating)?
2) When did the version with improved heat ducting enter service?
Reading accounts, some pilots have stated that the H's heating was terrible.. under -60 degrees Fahrenheit. The did not say anything about the J's heating; likely because most J's were now doing ground attack duties. The only clue I have is that the P-38J-15 had 'electrical improvements' and I'm not sure if that includes an electrical heat suit since those suits were available in 1943. 

I find that fighting at high altitude gives me an unfair advantage in that my pilot should be frozen, so I'd like to know the answer to this itchy question so I can fly the right P-38.

Thanks!

[Guppy35]

Obviously you are talking about the ETO guys with the cold.  I talked to an MTO P38F driver and he said he used to wrap YANK magazines around his legs to try and provide insulation to keep him warm at altitude.

PTO pilots didn't suffer the same problems but they tended to fly 22K and below.  The commentary there is that it was a welcome relief from the heat on the ground

I'm thinking it was the J/L variants that improved on the heating

I've seen photos of 38 drivers in the light blue electrically heated suits in the 43 time frame in the MTO so it was usuable in Gs and Hs anyway if not Fs.

[Soulyss]

The book I have lists the following changes from model to model (I'll start with the F as that was the first model to see combat)

P-38F:      Powerplant model change.  External store stations added.
P-38F-5:   New A-12 oxygen system added.
P-38F-13: Instruments modified.
P-38F-15: Maneuver flap setting introduced.
P-38G-3:  New B-13 turbosuperchargers, allowing cruising at higher power.
P-38G-5:  New radio.  New A-9 oxygen system.  Revised turbosupercharger.  Instrument changes.
P-38G-10: External bomb capacity upped to 3200 pounds total.  last 200 G models modified to carry two 300 gallon drop tanks.
P-38H:     New B-33 turbosuperchargers.  New Automatic engine controls.  Automatic oil cooler exit flap operations.  New engine P-38J:     New propellers. new higher capacity coolant radiators.
P-38J-10: New revised flat windscreen.  Improved cockpit heating. New control wheel. Added 2nd electrical generator.
P-39J-15: New wing leading edge fuel tanks.  Intercoolers moved from wings to engine nacelles.
P-38J-25: Underwing dive recovery flaps incorporated. Power boosted ailerons added.
P-38L:     Automatic powerplant controls. Uprated engines. Flush landing light to left wing. Tail warning radar added.
P-38L-5:  Underwing rocket-launcher system added. 
P-38M:    Nightfighter variant of P-38L. 

Those are the changes noted in America's 100K.  Seem to line up fairly well with my understanding of the development of the plane, but maybe someone else can confirm how accurate it is.

[Murdr]

P-39J-15: New wing leading edge fuel tanks.  Intercoolers moved from wings to engine nacelles.

Those are the changes noted in America's 100K.  Seem to line up fairly well with my understanding of the development of the plane, but maybe someone else can confirm how accurate it is.

There are a couple minor things on the list that I'd have to comb some books on to confirm/refute, but this one is definately wrong.  The "J model" distinction is the intercooler redesign, and it was prototyped with the J-1 block.  Changes to the cockpit heat, and fuel capacity were possible because of the intercooler change.  By the way, the LE tanks did not a J-15 make.  J-5s and J-10s recieved the LE tanks at mod centers while retaining their designations.

[Soulyss]

I was surprised when I came across it while running down the list of changes (I had thought that it was on the original J block too).  Was late and I wasn't able to cross reference anything so I just left it as is figuring that perhaps I was mistaken and if it was wrong someone would come long and correct it.

[SgtPappy]

Thanks guys.

Guppy, apparently it's said that only late P-38 models carried electric heating. I'm assuming it may have been a retrofit? Consulting other sources say that the P-38J's introduced heating from both engines. Later, the P-38J-15 (with the electric system mods and double generators) may have introduced the electric heating in December '43.

That last part's just me assuming.

[Guppy35]

Just an interesting tidbit I came across last night while reading the history of the 428th FS, 474th FG.  They got to England in early 44 and got their 38s on March 24, 1944.  They were issued 25 P38s, 22 of them were J-10s, 2 were J-5s and 1 was a J-15.  After they got them, they flew them to the mod centers for additional work to get them to ETO speed.  The Squadron CO took the J-15 btw

[SgtPappy]

Hah, he must've been quite the lucky bugger.

But it was the PTO gang that received the first J-15's, right? A lot of sources state that the J-15 entered service in December 1943, though much of the J's I read about in the ETO were received in '44.

[Guppy35]

Hah, he must've been quite the lucky bugger.

But it was the PTO gang that received the first J-15's, right? A lot of sources state that the J-15 entered service in December 1943, though much of the J's I read about in the ETO were received in '44.

I think the J's trickled in to the 2 8th FGs and the PTO groups about the same time in December 43 but were operated alongside G and Hs for a time.  MTO 38 Groups were sending pilots to England to get the hand me down P38Hs in February 44 so i think they got J's last.  I know that "Sad Sack" a P38F with the 82nd flew it's last combat mission in May 44  J-15s begain to appear in the MTO in April 44.

There are comments in both the 82nd and 1st FG histories where replacement pilots were surprised to be flying Gs and Hs, when they'd trained on Js in the States.

[SgtPappy]

Wow that's pretty late.
Knowing that the very first P-38J's were being built in August, it must've taken forever to register, deliver and fill squadrons with them to have them enter service only by that time.

[Guppy35]

Saw a comment in the 474th history.  The Group CO got the first J-25 with power assist and dive flaps on July 17, 1944.  Each of the squadrons had 4 L-1s at the end of October 44.  The rest were J-10, J-15 and J-25s

[Captain Virgil Hilts]

Wow that's pretty late.
Knowing that the very first P-38J's were being built in August, it must've taken forever to register, deliver and fill squadrons with them to have them enter service only by that time.

A P-38, built in Burbank California, had to be test flown, and certified. Then flown to the East coast. Then partially disassembled. Loaded on a ship, and taken across the big pond. Unloaded, semi-assembled, trucked to the depot, final assembled, tested again, and then delivered.

Also, P-38 production was slow, because it was single source, and Lockheed was also tasked with building B-17's. There were only two lines operating at best.