I think that fits in well with your realistic approach to this TL. And it's good to have the clunky OTL canopy being replaced as almost anything would be an improvement. A sliding hood certainly would be. Will the redesigned canopy include the single piece armored windscreen? The OTL P-38 used a windscreen with an armored glass slab mounted behind it. A single all in one armored windscreen is simpler with improved optics and is less prone to fogging up.
I think that fits in well with your realistic approach to this TL. And it's good to have the clunky OTL canopy being replaced as almost anything would be an improvement. A sliding hood certainly would be. Will the redesigned canopy include the single piece armored windscreen? The OTL P-38 used a windscreen with an armored glass slab mounted behind it. A single all in one armored windscreen is simpler with improved optics and is less prone to fogging up.
Ch.5 - Model 422 / P-38F Finalized (Feb 1942)
10 February 1942
Burbank, California, USA
In the weeks since the accident with 009, Kelly Johnson’s team had made significant progress on the P-38 Improvement Program. The updated airplane, now known internally as Model 422 but which the Air Corps had already designated P-38F, had several successful test flights since its repair in late December. Milo Burcham had taken over primary testing duties while Ralph Virden recovered from his injuries, but since Virden’s return the two pilots had traded duties on the aircraft.
Kelly’s canopy engineers had worked closely with process designers from DuPont and had solved the windshield mold issues and were able to re-design it with integral armored glass in a single piece. A representative from Imperial Chemical Industries—who was already stateside on behalf of the British Government—provided invaluable input from work they had done with Supermarine. The team applied this experience and was able to prototype a new single piece center sliding canopy. The first design had disappointed Kelly because of the off-set required for the sliding portion to clear the rear frame so he had worked directly with them to develop a new off-set locking mechanism. The device works by using a locking-lever in the cockpit to the pilot’s left which, when lifted (to the UNLOCK position), raises the rear corner of sliding canopy by about ¾ of an inch in its track. This provides ample clearance for the canopy to then back and over the rear glass. By raising the lever past the UNLOCK stop it pulls spring-pins clear of the track and disconnects the entire central canopy which can then be jettisoned for emergencies.
The sliding center canopy prevented the radio aerials from connecting to their previous position at the forward frame of the rear glass so they added a small post at the rear of the canopy assembly to which they could connect.
Kelly was pleased with the end result and both pilots praised the nearly unobstructed visibility it offered.
After the early December test flights, including the accident flight, the Army had sent over new priorities for the project and with the Air Corps now directly managing the manufacturing facilities those initiatives had received maximum effort.
The first priority was getting the manufacturing tooling and jigs completed for Model 422 production, which had been scheduled to start in April. With the Model 222 P-38E nearing the end of its production cycle in a few weeks, Kelly needed to be sure that the factory was ready for a quick and smooth transition to production of the new airplane.
Similar to the new canopy, the center-section leading edge alterations were being tooled up as sub-assemblies complete with the glycol and oil radiators installed. Also included in the assembly were the reserve fuel tanks, both Right and Left, which would fill the space between the radiator exit ducts and the main structural spar. The rest of the center wing assembly—everything from the main spar to the inboard Fowler Flaps--was unchanged from the previous model airplanes.
The current engineering challenge was from a memo from Ben Kelsey, whom Kelly learned had recently been given a temporary promotion to Lieutenant Colonel. The message was in direct response to both 009’s turbine failure and poor charge cooling identified in other performance tests of current block airplanes and contained the High Priority order that alternate inter-cooler installations be examined.
Kelly’s team had met several times to discuss the issue before they finally settled on halting work on the cowling design and instead open up the existing lower nacelle to airflow so they could install a core-type inter-cooler in the place previously occupied by the oil radiators. Although there was some concern over the space required for the air ducts a few quick measurements and test fittings settled those fears.
Over the past several weeks the design teams had come up with a suitable installation which required only a minor alteration to the intake on the nacelle. After getting the specific measurements and determining how best to run the ductwork, just a week earlier Kelly had sent the specification off to Garrett AiResearch so they could build the inter-coolers and they were now waiting for the first pair to test. Meanwhile the team was hard at work designing the installation specifications and were prepping 009 for fitment once the inter-coolers arrived.
With the plan to remove the embedded inter-coolers from the leading edge of the outer wings yet another group of Kelly’s designers were drafting the new empty sub-assemblies which will replace them. They will be able to use most of the existing jigs for these, which should ease production, with only a few of the leading edge stringers being truly re-engineered.
The aspect of all this engineering that Kelly was proud of was just how easy it has been to replace components of the airplane. The only part of the model 422 which could not be easily fit onto a model 222 was the extended gondola and canopy, everything else from the altered radiator installation and leading edge extension to the work on the inter-coolers, was completed as full sub-assemblies that can be bolted directly onto any of the existing model 222 airplanes.
At the end of the day, Kelly was happy to forward his Model 422 engineering and production status report on the Air Corps. This was shaping up to the air-plane he always knew it could be.
Burbank, California, USA
In the weeks since the accident with 009, Kelly Johnson’s team had made significant progress on the P-38 Improvement Program. The updated airplane, now known internally as Model 422 but which the Air Corps had already designated P-38F, had several successful test flights since its repair in late December. Milo Burcham had taken over primary testing duties while Ralph Virden recovered from his injuries, but since Virden’s return the two pilots had traded duties on the aircraft.
Kelly’s canopy engineers had worked closely with process designers from DuPont and had solved the windshield mold issues and were able to re-design it with integral armored glass in a single piece. A representative from Imperial Chemical Industries—who was already stateside on behalf of the British Government—provided invaluable input from work they had done with Supermarine. The team applied this experience and was able to prototype a new single piece center sliding canopy. The first design had disappointed Kelly because of the off-set required for the sliding portion to clear the rear frame so he had worked directly with them to develop a new off-set locking mechanism. The device works by using a locking-lever in the cockpit to the pilot’s left which, when lifted (to the UNLOCK position), raises the rear corner of sliding canopy by about ¾ of an inch in its track. This provides ample clearance for the canopy to then back and over the rear glass. By raising the lever past the UNLOCK stop it pulls spring-pins clear of the track and disconnects the entire central canopy which can then be jettisoned for emergencies.
The sliding center canopy prevented the radio aerials from connecting to their previous position at the forward frame of the rear glass so they added a small post at the rear of the canopy assembly to which they could connect.
Kelly was pleased with the end result and both pilots praised the nearly unobstructed visibility it offered.
After the early December test flights, including the accident flight, the Army had sent over new priorities for the project and with the Air Corps now directly managing the manufacturing facilities those initiatives had received maximum effort.
The first priority was getting the manufacturing tooling and jigs completed for Model 422 production, which had been scheduled to start in April. With the Model 222 P-38E nearing the end of its production cycle in a few weeks, Kelly needed to be sure that the factory was ready for a quick and smooth transition to production of the new airplane.
Similar to the new canopy, the center-section leading edge alterations were being tooled up as sub-assemblies complete with the glycol and oil radiators installed. Also included in the assembly were the reserve fuel tanks, both Right and Left, which would fill the space between the radiator exit ducts and the main structural spar. The rest of the center wing assembly—everything from the main spar to the inboard Fowler Flaps--was unchanged from the previous model airplanes.
The current engineering challenge was from a memo from Ben Kelsey, whom Kelly learned had recently been given a temporary promotion to Lieutenant Colonel. The message was in direct response to both 009’s turbine failure and poor charge cooling identified in other performance tests of current block airplanes and contained the High Priority order that alternate inter-cooler installations be examined.
Kelly’s team had met several times to discuss the issue before they finally settled on halting work on the cowling design and instead open up the existing lower nacelle to airflow so they could install a core-type inter-cooler in the place previously occupied by the oil radiators. Although there was some concern over the space required for the air ducts a few quick measurements and test fittings settled those fears.
Over the past several weeks the design teams had come up with a suitable installation which required only a minor alteration to the intake on the nacelle. After getting the specific measurements and determining how best to run the ductwork, just a week earlier Kelly had sent the specification off to Garrett AiResearch so they could build the inter-coolers and they were now waiting for the first pair to test. Meanwhile the team was hard at work designing the installation specifications and were prepping 009 for fitment once the inter-coolers arrived.
With the plan to remove the embedded inter-coolers from the leading edge of the outer wings yet another group of Kelly’s designers were drafting the new empty sub-assemblies which will replace them. They will be able to use most of the existing jigs for these, which should ease production, with only a few of the leading edge stringers being truly re-engineered.
The aspect of all this engineering that Kelly was proud of was just how easy it has been to replace components of the airplane. The only part of the model 422 which could not be easily fit onto a model 222 was the extended gondola and canopy, everything else from the altered radiator installation and leading edge extension to the work on the inter-coolers, was completed as full sub-assemblies that can be bolted directly onto any of the existing model 222 airplanes.
At the end of the day, Kelly was happy to forward his Model 422 engineering and production status report on the Air Corps. This was shaping up to the air-plane he always knew it could be.
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Lockheed is exploring cabin pressurization with Model 522 (XP-49--I have always found it curious how IOTL they jumped from the "export" P-38 as 322 to the XP-49 as 522, then went back and used 422 with nacelle redesign on the P-38J) but haven't yet progressed to a point of testing it and certainly are certainly not ready to production in six or seven weeks. The goal right now is to make the current airplane as good as it can possibly be with minimal effort and get it into the war ASAP, just as in OTL. Pressurization is on the docket for development but there is not immediate need.
Garrett, at this time, just builds radiators (the Oil Radiators already in use on the P-38 were from AiResearch). His work on turbines and cabin pressurization comes later...although maybe there is opportunity to collaborate.
The original cockpit heater is still in place. The cold cockpit issues really didn't come to fore until they started getting combat experience with it. IOTL the eventual solution was two-fold: add an electrical outlet for a "Bunny suit" and re-route the gun heat to the cockpit (the gun compartment was then electrically heated). This was almost adequate. Luckily, there are nice hot Prestone/glycol radiators now installed right next to cockpit on the ATL Model 422 which should make it easier to scavenge some extra heat for the cockpit when the time comes for it. While they are no where near as hot as heater cores off the engine would be, it might be possible to get some more warm air off them.
I've never understood the fascination with sliding. Why didn't they just hinge it on one side, like the Germans did?
Except for that question you probably can't answer,
well done, again. Those drawings are detailed enough a modeller could easily reproduce the *Model 422, if inclined. (I don't have anything like the skill required, but I can dream.)The advantage of sliding is two-fold: first it eases access and allows entry from either side; and, they can (usually) be opened in flight which allows airflow through the cockpit. I say usually because I am not certain if the revisions to TTL P-38 will correct the buffetting when the side windows were open. I need to spend more time figuring that out.
Fair enough. Maybe I'm too conditioned to jets & wondering why you'd want to open the canopy, except to step outside.
The XP-49 had a side-opening canopy, possibly suitable for pressurization, and less framey. I don't think we have the wind tunnel facilities at the AH research lab to determine the viability of an open canopy in flight.
Just out of curiosity could the P-38 be armed with 2 or 4 more 50 cal. Machine guns instead of the one 20mm gun, 50 cal. Configuration? I am thinking if at least one Lightning variant has the standard armament it will make it easier on the supply chain. Perhaps send a six or eight gun P-38 to China with Chennault? OTL Chennault did not want to deal with a two engine fighter but a another 8 gun fighter like the Thunderbolt is too good of a plane to pass over especially if it has range. But first I should ask could the Lightning handle the weight and ammo or would we be sacrificing range for the guns?
First, we'll need a tunnel. Then, we'll need some fanboys. But they're in the wrong forum.
There really isn't enough room in the nose for 8 guns and the 4 + 1 combo of the standard load out has a better weight of fire than 6 .50's. The best option to improve the firepower would probably 4 x 20mm (or 5 if you can fit them) but then you loose duration of fire due to holding less ammunition.
There was an experiment with 8 .50s in the nose; unfortunately, the details are scarce: picture
Granted, 4 cannons proposal sounds great, even a 3 cannon + extra ammo.
A P-38 with three 20mm could serve as a mini-Beaufighter. Skip the A-36 and debut the Mustang strictly as a fighter.
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Wow, thanks for sharing that, I had never heard of that.
I think belly guns on the sides of the center fuselage under the wings, two per side, could work. The placement will help avoid too much shift in center of gravity so the weight won't be too hard to handle. You could even go Mossie style an use 20mm.
Hrm. Are those large gun pods in the underwing payload position? would it have been better to use two of the blister pods such as used on the B-25/A-26 later in the war? 2 machine guns at 300 rounds per gun and can be mounted on the hull or on a bomb pylon.
EDIT: sorry, saw all the guns on second glance. I immediately saw the gun pods and thought you were referring to those.
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