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The P-38 didn't suffer from bad turbocharger controls..
That is not what the Americans were saying at the time Greg, and it is nothing specific to the P38, it
applies to many Allied aircraft of the time too, but a twin engine with turbos places particularly
high demand on controls.
Wright-Field correspondance 31st March 1945, in connection with BMW801D Kommandogerat.
Archive File:
NARA - P301937 - Single Lever Throttle Control for P38 - Visit to Allison
View attachment 567651
Note that the P-38, unlike most other turbosupercharger equipped aircraft, had no direct control over the turbosupercharger. There was a linkage in the throttle controls that also worked with the turbo and that was it, other than other normal engine controls. In contrast, in the P-47 the pilot had the ability to adjust the turbo, being instructed to set the controls so that the turbo overspeed light blinked off and on, and of course on the bombers they had turbo controls.
When they added a manifold pressure regulator to the later V-1710 engines that caused problems. The engine manifold pressure regulator and the turbo regulator would fight each other, leading to a jerky flight. While no doubt unpleasant for the fighters, for the photo recon Lightnings this was a serious problem. You need smooth and steady flight for good pictures. So at the 9th Photo Recon Squadron, and probably at other recon units, the manifold pressure regulators were removed.
Generally speaking, Allison V-1710 equipped fighters had no supercharger controls at all. Even with the P-63C with its auxiliary supercharger, the pilot had no control over the speed of the auxiliary unit nor even if it was operating at all. On the P-63C they eliminated the prop controls and had the throttle set up to take care of that adjustment automatically.
On the F4U, F6F, and P-61 airplanes the pilot could make many more adjustments to the supercharger stages, which must have been a real pain in combat.
Am I to believe that United States aircraft engineers never investigated automated engine controls before they had a look the Kommandogerät ???
Yes, that is true and is what the P-63 pilot's manual says.
One of the disadvantages of mechanically driven supercharging was that it if automatic it usually had a specific speed shift point. For the Merlin P-51 and the Spit IX that was around 18,000 ft and was controlled by an aneroid device. German pilots knew that if they are careful to fight around that altitude the Allied pilots in Mustangs and Spits would be troubled with having to pull and push on the throttle frequently as their engines surged with power when the supercharger switched to high speed and then dropped back to low speed as the combat altitude varied. And if there were multiple P-51's or Spits in the fight, their unit cohesion was destroyed, since aneroid device setting always varied from airplane to airplane. The BF-109 had a fluid coupled supercharger drive and that eliminated such shift points, and I believe the FW-190D was the same way; the P-63 had that same feature as well.
Some of the P-51's escorting the B-29's had their spring loaded momentary "On" high speed supercharger switches replaced with regular toggle switches so they could defeat the automatic feature and use the high speed supercharger setting below the aneroid device setting. The Japanese knew to fight the Mustangs down around 15,000 ft, optimum altitude for their airplanes, but where the P-51 was starting to run out of steam.
Based on reading the various P-51 pilot's manuals I have on hand it appears that in late WWII or postwar the supercharger automatic switch was changed to one using ram air pressure. I assume that meant the switch occured at lower altitude if you were not going very fast.
The P-38 didn't suffer from bad turbocharger controls.
Note that the P-38, unlike most other turbosupercharger equipped aircraft, had no direct control over the turbosupercharger. There was a linkage in the throttle controls that also worked with the turbo and that was it, other than other normal engine controls. In contrast, in the P-47 the pilot had the ability to adjust the turbo, being instructed to set the controls so that the turbo overspeed light blinked off and on, and of course on the bombers they had turbo controls.
I would point out that "automatic mixture control" is still a switch, its just once you have SET rich or lean... it then ensures that is maintained.
I read that automatic boost control originated in airliners before the war.The maximum you can fly without supplementary oxygen is about 10,000 ft. Given that pre-war airliners were neither pressurized nor carried oxygen, flying higher than 10,000 ft was as high as you would go, normally. You do not need auto boost control for that.
The C-54 was a godsend for the route over the Hump. But it was designed as an airliner and had to wait until air supremacy had been secured over Burma, since the higher routes were not available to it.