109s autoprop - did it ever existed?

[JG53Frankyboy]

well, the manual system you have in CoD now and a "one lever" system where each rpm was "locked" to a special ATA setting, such combinations were called "Leistungszustand".The automatic controlled the propeller pitch to achive that.,

This automatic could still be 'overwritten' manually by the pilot if desired.

[JG14_Jagr]

When you see how complex and pilot intensive all that is you can see why the Fw190 was such a difference animal with the "automatic" engine controls..

[IvanK]

Auto function in the case of the 109E came in to general operational use in late 1940. The earliest reference I have seen is Sep 18 1940 when it was being tested in a machine of II/JG53. The 109E in the RAF museum Hendon was Field Modded to AUTO it is an E3B I believe. It was brought down on 27 Nov 1940. Steinhilper's book "A Spitfire on my tail" refers specifically to Manual prop pitch technique still being used as late as Sept 1940. There is a translated OKL document discussing the introduction of AUTO on the 109E its subject header is "Increasing the revs of engine types DB601A and DB601N. It is hand dated 14Th Nov 1940.

Here is an image of the translated document :

[Kurfurst]

Originally Posted by IvanK

Auto function in the case of the 109E came in to general operational use in late 1940. The earliest reference I have seen is Sep 18 1940 when it was being tested in a machine of II/JG53. The 109E in the RAF museum Hendon was Field Modded to AUTO it is an E3B I believe. It was brought down on 27 Nov 1940. Steinhilper's book "A Spitfire on my tail" refers specifically to Manual prop pitch technique still being used as late as Sept 1940. There is a translated OKL document discussing the introduction of AUTO on the 109E its subject header is "Increasing the revs of engine types DB601A and DB601N. It is hand dated 14Th Nov 1940.

I note it here, too before someone starts a new myth..

The information regarding the date of availibilty of the auto function is wrong.

The Bf 109E1 and E-3 manual of December 1939 already notes the automatic system (Verstellautomatik), and gives different operating instructions to those planes with the old manual system ("Options 1 and 2") and the auto prop pitch system.

Auto and manual props pitch systems also had differently designated VDM propellor type numbers.

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

[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.

[IvanK]

By general operational employment I am referring to general Squadron use, i.e. How many aircraft were equipped with it and at what date. Most publications on the 109 refer to Auto as a late 1940 introduction.

the JG53 account above is a typical example... "17 Sept 1940". As are the references to it in the book Messerschmit BF109 Recognition Manual by Marco Fernandez-Sommerau page 103:

"A significant improvement from mid 1940 was the adoption of an electro-mechanic automatic pitch regulator ..."

The AJ Press publication on the "ME 109" Pt 1 page 46 refers to it being tested in "Summer 1940".

The RAF and French test reports on the E3. The RAF handling notes on the E3 all refer to the non auto version.... though I presume these are all based on the same aircraft.

The Translated document referring to its initial introduction of auto.... "has been introduced" , though I accept the hand written date on the document isn't iron clad.



Steinhilper's book "Spitfire on my tail" refers to manual prop pitch use in Sept 1940 and the difficulty on training new pilots on the technique to use it to maximise performance.

So I am not so sure its "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." Late 1940 production I would agree with as I would for earlier aircraft being retro fitted.

The general thrust from various sources is that general operational (i.e. squadron) use of auto didn't occur until late 1940. Thats not to say that Auto didn't exist conceptually or limited use prior to then. Based on the general knowledge it would seem that Manual was the most common system until at least Sept 1940 i.e. the Main accepted time line of the Battle of Britain.

In the end we are then discussing how all this info translates to COD use. So far the E3 and E3B are the Manual system. I would anticipate the E4 and later models when they come to be equipped with the Auto system. A datal based system could also be applied to E3's allowing Auto use post Sept/Oct 1940 ? . An intermediate step might also include the Rocker switch on the throttle with Manual as well.

Kurfurst what is the exact date of the Handbook and or its last amendment date from which you refer ?

[Pluto]

... I remeber in the old IL2 you could change from automatic pitch to manual pitch control in the ME109, even the early Emils.
But it was not advisable to control pitch manually, it quickly turned too high and busted your engine, so I always flew the 109 with auto-pitch-control.

Which one is more realistic, I dont know, anyway you get used to both.

[JG53Frankyboy]

not only Prien is talking of this testing of a automatik in his JG53 History book.



Also Steinhilper is mentioning in his book how the pilots handled thier manual propellers in their 109s.

[ATAG_Doc]

"the automatic device..."

What's that thing called again?