According to the manual's 1946 edition (par.19-20), Spitfires with 60-70 series of Merlins got an automatic RPM control with an "override lever" at some point in their production. In the manual the aircraft are divided into "early" and "later", and the only reference I found is that Mk.IXs with Merlin 61 and 63 never got it (par.35-36).
So, what remains is that: 1) Spitfires got the override lever somewhere along the production; 2) It was late enough to only affect LF IX, HF IX and Mk.XVI (modifications that appeared from 1943 onward);
The primary question is when (even if approximately) the automatic RPM control was implemented into production.
So, what remains is that: 1) Spitfires got the override lever somewhere along the production; 2) It was late enough to only affect LF IX, HF IX and Mk.XVI (modifications that appeared from 1943 onward);
The primary question is when (even if approximately) the automatic RPM control was implemented into production.
