109 prop pitch (rpm) and the supercharger

[kohmelo]

Originally Posted by Crumpp

The pitch must be constantly adjusted to maintain rpm as the speed increases!

ummm... So he was only shifting his supercharger rpm? could you please explain to me how he did that.

[Crumpp]

that is non standard pitch management at high altitudes as described by a LW pilot who has actually been there

He does not say or do anything "non-standard". He just explains the right way to manage the pitch on the propeller is to constantly change it.

That is why you hear the pulsing of the pitch change. You hear that at any governor check on run up of a CSP equipped aircraft.

[Robo.]

Originally Posted by Crumpp

He does not say or do anything "non-standard". He just explains the right way to manage the pitch on the propeller is to constantly change it.

Oh yes he does indeed. Below the fth there was no point in overreving the engine for a speed gain. At higher altitudes, there apparently was. As I said, you completely missed the point of this conversation and Steinhilper did not maintain the rpm, he was changing it constantly into higher values (hence the term 'overreving'). I am sure every reader of this thread understood that by changing the rpm up and down you're not exactly 'maintaining' it.

The interesting technical fact here is the supercharger function regarding engine rpm, because this seems not to be modelled in the game yet and as far I can tell, the engine management described by BoB pilots won't work in game. The engine works just like below FTH.

[Crumpp]

Oh yes he does indeed.

I don't see it in any of the direct quotes.

[Robo.]

Originally Posted by Crumpp

I don't see it in any of the direct quotes.

He didn't say explicitly it was non standard, but that was the main reason he described it in his book. And the main reason we quote that part in here. I am sure that even you can see that. It would be good to have this modelled in the sim, don't you think?

[Crumpp]

He didn't say explicitly it was non standard, but that was the main reason he described it in his book. And the main reason we quote that part in here. I am sure that even you can see that.

Well, the only quotes I can find do not say a thing about non-standard or varying rpm.

They only talk about managing pitch.

[ACE-OF-ACES]

Originally Posted by Crumpp

Well, the only quotes I can find do not say a thing about non-standard or varying rpm.

They only talk about managing pitch.

Actully that is not correct..

Steinhilper talks about varying the pitch of the prop to increase the RPM of the engine..

Originally Posted by Ulrich Steinhilper

When we flew at that height, the engine only just gave enough pull and we constantly changed the propeller pitch and RPM to improve the performance. With a flat pitch we could increase the RPM of the engine and get more pressure from the super-charger. Then, by changing the pitch to a coarser setting, we could make up some speed.

Hope that helps! S!

[kohmelo]

Originally Posted by Steinhilper

Of special importance was teachign them how to change the pitch of their propeller to get maximum pull from the engine at high altitude.
A flat pitch would allow the enginer to rev up to its maximum so that the super-charger would deliver the maximum vlume o air to the cylinders and
produce optimum power; chnaging to coarser pitch would have that enginer power converted into more pull and consequently speed our rate of climb.
It was vital they mastered this technique if they were to keep uo in a battl climb or at high altitude.

Originally Posted by Technical Sheet Issued by the Quartermaster General Berlin 14th November 1940.

To increase the performance of the Me 109 an increase in the revs for a short time at heights over 5.5 km. will be in future be
permissable. For the DB 601 A engine the normal maximum revs are 2400.
Above full pressure height they may be for a short time be increased
from 2400 to 2600...

Originally Posted by Technical Sheet Issued by the Quartermaster General Berlin 14th November 1940.

...the excess revs can only be obtained by
means of the thumb switch after switching off the automatic device.
In doing this the danger of an additional impermissable increase in
the revs must be watched.

Sure I concure they are maintaining engine Rpm with pitch changes...

[Crumpp]

2400 to 2600...

Yep, they were allowed to increase rpm to 2600. In order to maintain that increased rpm overboost condition, they have to manage the pitch just as Steinhilper says!!


Absolutely NOTHING about changing rpm constantly......

[kohmelo]

Originally Posted by Crumpp

Yep, they were allowed to increase rpm to 2600. In order to maintain that increased rpm overboost condition, they have to manage the pitch just as Steinhilper says!!


Absolutely NOTHING about changing rpm constantly......

Above full pressure height they may be for a short time be increased
from 2400 to 2600...