# 109 controllable pitch propeller



## bart1727 (Aug 18, 2011)

Hi all.
i would know one stuff about bf109.
When does bf 109 had got automatic pitch propeller?
I think it s since bf 109 emil it s auto pitch prop but in COD game (cliff of dover) in bf 109 manuel it s written it s manuel pitch propeller but he has a auto prop pitch button in cokpit.
WTF ???????? lool
THKS all ^^.


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## stona (Aug 18, 2011)

The Bf109E had a manual pitch control. It was not a constant speed unit. Infact there was no propeller governor. British pilots who flew the Emil were amazed by this,it is unusual for an aircraft of this type.The pilot must set the pitch to give the r.p.m. desired for any condition of flight. There is a pitch indicator in the cockpit (looks a bit like a clock face) which was connected to the electric motor which altered the pitch. The pitch could be set anywhere between 22.5 degrees to 90 degrees (fully feathered).
Steve


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## Ivan1GFP (Aug 18, 2011)

Did later versions have a constant speed prop?

- Ivan.


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## Ratsel (Aug 18, 2011)

As for the Emils Auto-prop pitch, the earliest reference I can find is the December 1939 E-1 and E-3 manual, which notes already that there are some planes 'mit Verstellautomatik', ie. auto prop pitch.


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## stona (Aug 19, 2011)

I think Ratsel's post refers to L.Dv. 556/3 BF 109 E Flugzeughandbuch, of 16 December 1939. The handbook refers to the operation of the "Luftschrauben Verstellautomatik".It also notes that some aircraft are without this automatic system. Accounts from pilots at the time would suggest that many aircraft did not have any automatic control.
It may simply depend which propeller system was fitted.There were two used on the Bf109E,both from VDM. The 9-11081A used a manual pitch control and the 9-11081E had the automatic system.
For the F series,and carried on afterwards, an automatic option was fitted as standard but the manual option was retained.

From a British report on the Bf109F.

" The airscrew has now been fitted with a constant speed unit of novel design. The r.p.m. at which the airscrew is controlled depends on the position of the throttle lever.With the throttle lever fully forward the unit is set to control at 2,600 r.p.m. When the throttle lever is moved back the r.p.m.automatically fall an appropriate amount.
The constant speed unit can be cut out by the pilot and the airscrew pitch controlled in the same way as on the Me 109E"

Here's another excerpt from the R.A.E. report on Pingel's F-2

"The constant speed airscrew is fully automatic and requires no operation
by the pilot, as r.p.m. and pitch setting are governed by the throttle opening
and engine load. This is a great advantage in combat, being one thing
less for the pilot to worry about. He can, however, control the pitch
manually in the event of failure of the automatic control."

Steve


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## bart1727 (Aug 19, 2011)

thks all to reply and specially Stona


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## stona (Aug 19, 2011)

One final point on the manual option. U.S.pilots who tested a G-6 found that they preferred to land with manual control of the propeller pitch. The British test pilots did not do this nor as far as I can establish was it common practice for Luftwaffe pilots. I think it was an option,not an emergency fall back in case the automatic control failed as suggested in the Farnborough (R.A.E.) report.
Steve


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## Ivan1GFP (Aug 19, 2011)

From what I have read, the Spitfire Mk.I didn't have a constant speed propeller either.

- Ivan.


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## stona (Aug 19, 2011)

The first 77 Spitfires had the two bladed fixed wooden airscrew. After this the MkI was fitted with a de Havilland, three bladed,two pitch,metal propeller. So you are correct to say they did not initially have a constant speed unit,though some did have the Rotol CSU fitted. Rotol was a joint venture between Rolls Royce and The Bristol Aircraft Company.
Back in 1935, following the success of their own Comet racer, de Havilland acquired a licence from Hamilton Standard in the United States for a variable-pitch propeller mechanism.
As of 24/6/40 de Havilland started converting all Spitfires,Hurricanes and Defiants in service to accept a constant speed unit.
De Havilland manufactured the relevant parts,including those to adapt the Merlin engine to drive the hydraulic pump. They did not need to change the blades but did have to increase their pitch range. The time allowed to convert a squadron was ten days and in less than a month,by 20/7/40,all Spitfire squadrons had been converted.
On 16/8/40 every Spitfire and Hurricane in service,over 1000 aircraft,had been converted.

The spinners fitted to all these aircraft would have been familiar to their German adversaries. They were VDM spinners,manufactured by Constant-Speed Airscrews Ltd in Warwick. They had bought the licence before the war.

Cheers
Steve


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## Mossie (Jun 14, 2012)

Could someone explain to me how the propeller pitch indicator FL.18503 worked. I found that 10 mins on the clock = 1 degree of pitch and that for the Bf109E1 it has a range of 22.5 to 90 degrees (feathered). With two hands and no numbers it does seem a bit odd.


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## razor1uk (Jun 16, 2012)

Mossie, that is actually very good question, myself along with you, and others (particularly those whom are also within the IL-2 flyers/players community) I am sure too would also wish to know, hopefully some kind and knowledgable 'bod' can explain that 

I believe you deserve a junior members virtual pint for it as well M 8) muhuhahaha


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## stona (Jun 16, 2012)

You are basically correct. 10 mins is equal to 1 degree of pitch or,another way, 1 hour is equal to 6 degrees.
Off the top of my head I think I remember that the normal procedure was for the indicator to read 12.30 at 22.5 degrees pitch.
Cheers
Steve


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