109s autoprop - did it ever existed?

[Kurfurst]

Originally Posted by IvanK

Do you have documentation Kurfurst that shows operational employment of the Auto function rather than early test data ? I would be happy to be proven wrong.

The first known documentation of automatic propellor pitch (Luftschauben Verstellautomatik) control appears in late 1939, in the L.Dv. 556/3 (Entwurf) BF 109 E Flugzeughandbuch, promulageted 16 December, 1939, Berlin.

This is the operational handbook for the Bf 109E, not some test report. It instructs the pilots how to use the systems of the aircraft.

The Handbook takes numerous notes on the operation of the Luftschauben Verstellautomatik in various conditions, and also notes that some aircraft are without this automatic system. Ie.

Page 17, I. Startferigmachen, Step 7.
' Prüfe, ob Luftschrauben-Verstellautomatik eingeschaltet ist (Kippschalteran linker Rumpfwand; Selbstschalter in Schalttfel. '

Page 18, IV. Flug, C. Betriebsdaten.
' Bei Flugzeugen ohne Luftschrauben-Verstellautomatik, Luftschraubensteigung durch Daumenschalter am Gashebel oder Verstellschraubeschalter am Gerätebrett so einstellen, daß die verstehend angegeben Werte für Drehzahl und Ladedruck eingeschalten werden. 1,3 ata und 2400 U/min nicht überschreiten!'
' Für Sperrflug Luftschrauben-Verstellautomatik auschalten, (Kippschalter an linker Rumpfwand) und Luftschraubensteigung durch Daumschalter am Gashebel oder Verstellscraubenschalter am Gerätebrett einstellen.'

Page 20, V. Landung, Step 2., and VI. Verhalten in besonderen Fällen, A. Durchstarten, Step 1:
' Bei Flugzeugen ohne Luftschrauben-Verstellautomatik, Luftschraubensteigung durch Daumenschalter am Gashebel oder Verstellschraubeschalter am Gerätebrett auf 12 Uhr. '

Page 21, VI. Verhalten in besonderen Fällen, C. Versagen der Luftschrauben-Verstellautomatik, Step 1.
' Luftschrauben-Verstellautomatik durch Kippschalter an linker Rumpfwand auschalten. '

Page 21, VI. Verhalten in besonderen Fällen, D. Notlandung, Step 3.
' Luftschaube in Segelflug : Luftschrauben-Verstellautomatik durch Kippschalter an linker Rumpfwand auschalten, und Luftschraube durch Daumenschalter am Gashebel oder Verstellschraubeschalter am Gerätebrett in Segelflug bringen. '

I have indicated in my post general operational employment not that it didn't exist in some form prior to that.

General operational employment - ie. that its not only 'experienced with' or something like that - is indicated by the fact that they issued an operating manual about how to use it. Obviously the system was installed into aircraft. The manual came in December 1939, although AUTO might have been around earlier, but we are not aware of it.

Of course the 109E has been in production for over a year by that time, with more than a thousend produced, so I presume that many that were produced during 1938 and some in 1939 only had the manual system, and these aircraft were still in use with some Gruppen, for example the noted use in II/JG 53.

IMO two random accounts (one from I./JG 52, one from II./JG 53) do not cast any serious doubt that a system that was introduced at least 10 months before was not yet in general operational use. It shows that I./JG 52 and II./JG 53 did not had it, for some time.
Its rather safe to assume that all new production aircraft had it (for example Emils produced in 1940), while the older machines were gradually retrofitted with the system.