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View Full Version : Questions about 109E and Spitfire @ Hurricane mark I



Freiwillige
08-13-2009, 01:52 PM
Question 1.
I know that during the Battle Of Britain Most 109E's had manual only pitch. Was the E-4 the first to be manufactured with Auto pitch or were they retrofitted in the field? Was it a constant speed prop or like the later Bf-109F's fully automated into the engine management system?

Question 2.
At the height of BOB July and August what percentage of Spitfire and Hurricane squadrons were converted from two speed props to Constant speed props?

Freiwillige
08-13-2009, 01:52 PM
Question 1.
I know that during the Battle Of Britain Most 109E's had manual only pitch. Was the E-4 the first to be manufactured with Auto pitch or were they retrofitted in the field? Was it a constant speed prop or like the later Bf-109F's fully automated into the engine management system?

Question 2.
At the height of BOB July and August what percentage of Spitfire and Hurricane squadrons were converted from two speed props to Constant speed props?

Xiolablu3
08-13-2009, 02:16 PM
I am pretty sure that all FRONTLINE Spits and Hurris were converted to constant speeds before the 'official' BOB started.

I think its the two bladed model 'Dunkirk' Mk1 which has the non-constant speed prop isnt it?

Freiwillige
08-14-2009, 03:01 AM
I am pretty sure that field conversions were going on at the height of the battle making Spit mk1's into Mk1 A's

hop2002
08-14-2009, 03:59 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">At the height of BOB July and August </div></BLOCKQUOTE>

The height of the BoB was mid August to mid September. July was relatively quiet. As an illustration, German fighter losses:

1 - 7 July - 12
8 - 14 July - 28
15 - 21 July - 12
22 - 4 Aug - 10
5 - 11 Aug - 45
12 - 18 Aug - 157
19 - 25 Aug - 46
26 - 1 Sep - 111
2 - 8 Sep - 129
9 - 15 Sep - 61
16 - 22 Sep - 21
22 - 29 Sep - 69

So the week 12 - 18 August saw more German fighter losses than the 6 previous weeks combined.

As to when the Spitfires and Hurricanes were converted, work began in June. Every Spitfire and Hurricane in Fighter Command, including those in storage, had been converted by 16 August.

I'd assume priority was given to 11 Group, with fighters in the north being done next, and those in storage last.

Looking at the figures, and assuming 11 Group was converted during July, you have about 10% of fighter losses occurring during the period when 11 Group was equipping with CS props. That would suggest about 5% of the fighting was carried out by 2 pitch Spitfires and Hurricanes. That's a very rough estimate, of course.

yuuppers
08-14-2009, 05:30 AM
A great post on 100 octane fuel use during BoB. This should put to rest any arguments from the nay sayers once and for all.

http://www.ww2aircraft.net/for...af-pt-2-a-20108.html (http://www.ww2aircraft.net/forum/aviation/use-100-octane-fuel-raf-pt-2-a-20108.html)

Kurfurst__
08-14-2009, 08:55 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Freiwillige:
Question 1.
I know that during the Battle Of Britain Most 109E's had manual only pitch. Was the E-4 the first to be manufactured with Auto pitch or were they retrofitted in the field? Was it a constant speed prop or like the later Bf-109F's fully automated into the engine management system? </div></BLOCKQUOTE>

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. 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; this latter is confirmed by oral accounts of Bf 109E pilots.

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. '

VDM documentation shows the following propellor types used for the Bf 109E :


Bf 109E ohne Automatik : 9-11081A (DB601A and N)
Bf 109E mit Automatik : 9-11081E (DB601A and N)


So obviously both automatic and manual (two types of the latter existed - 1. pitch controller lever on the dashboard and 2. pitch controller thumb switch on the throttle) prop pitch controls were around by late 1939. How many aircraft were fitted with each is difficult to tell, but obviously both automatic and manual control systems were used in the Batttle.

It would seem that the Verstellautomatik was replacing the old manual system completely by November 1940:
http://www.kurfurst.org/Engine...01_RPM_increase.html (http://www.kurfurst.org/Engine/Boostclearances/DB601_RPM_increase.html)

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
Question 2.
At the height of BOB July and August what percentage of Spitfire and Hurricane squadrons were converted from two speed props to Constant speed props? </div></BLOCKQUOTE>

During the Battle of France and the very start of the Battle in July, they had two-pitch airscrews, and in case of the first 78 Spitfires built, fixed propellers.

As Hop noted, they started the work in the end of June/early July. By mid August, something like 1000+ aircraft was retrofitted. They went from station to station, demonstrated the changing process to the groundcrew on a number of aircraft, and let them finish the process then. I think I have it somewhere how long it did take to finish one station, but its fairly safe to say that when the skirmish started in July, almost all had two-pitch airscrews, but by when the German offensive started proper on Adlertag, almost all had a constant speed props. Spitfires had priority over Hurricane Squadrons though.

Freiwillige
08-14-2009, 10:06 AM
Danke Kurfurst!