enginehistory.org

[jjuutinen]

Just been wondering how far behind US engine makers were in introducing automatic engine controls to even ti their fighter engines. E.g. even late designs like the F8F had much higher pilot workload than comparable German aircraft.

[jschauer]

I can't answer that question, but I suspect the reason we didn't have it was due to mass production reasons, i.e. they didn't want to disrupt the production lines to add a new system or spend time testing the system. Look at the BA series of the R-3350 used in the B-29 as an example. It was a relatively new engine put in to production before all of the testing was completed. Another example was the building of the atomic bomb. The factories that produced the fission materials were built before they knew what was going to be put in the buildings. They had a general idea, but no definative plans.

[jjuutinen]

That explanation does work for the major series produced ones, but even late desigs when did not really have such urgency like the F8F, F7F failed to have the level of automation that was available in German aircraft by the beginning of the war. What is interesting is that aircraft with radials had fewer automatics than those with the Allison or the Merlin. The same difference applies to British designs. E.g. the Seafire 47 had fully automatic oil and coolant rads, mixture control (those with the Griffon 88 had no mixture lever) etc. Consider that the early Bf 109F was already a near true single engne lever airplane as the prop pitch change was by a throttle mounted toggle switch and a normal flight could be executed without touching the switch.

The Jumo 213 had also interesting engine controls. It had "charge mass" control. I.e. when e.g. the TO setting was selected, the rpm remained fixed but the boost varied according to the ambient temperature, allways delivering the same air mass to cylinders.