Bf-109 Elec. Propeller Pitch control, .. how it works?

Does that mean that torque was not transmitted while the engine was stopped?

Great to know!

So, is it going to get fixed for the next update Yo-Yo ?

And, a big THANK YOU to the OP - Otto - because thx to his persistence, and attention to detail, and after all, knowledge, we got that sorted out :thumbup:

Yes. Very hard to notice because at the rpm slow model is actual the aerodynamic forces are negligible.

So windmilling torque was not transmitted while the slow model was active?

Great to know!

 

So, is it going to get fixed for the next update Yo-Yo ?

 

And, a big THANK YOU to the OP - Otto - because thx to his persistence, and attention to detail, and after all, knowledge, we got that sorted out :thumbup:

you're welcome!! Jcomm :smilewink:

Speaking about pitch control issues, is the pitch automation logic correct? Try this:

1. Fly at 3 km

2. Throttle back at enter a shallow dive maintaining 500 km/h

3. Apply full throttle when altitude drops below 1 km

In the Fw-190 the power and RPM return immediately, after 1-2 seconds you have 3250 RPM. In the Bf-109 it takes 8-10 seconds for the prop to slowly adjust pitch to max RPM (2800). No other airplane in DCS has such sluggish prop pitch control.

I started noticing this through the sound of the prop recovering the RPMs... I found it strange because it was so faint... then noticed the PRMs were rather low, and though the engine had a problem, but then saw it slowly recovering...

Speaking about pitch control issues, is the pitch automation logic correct? Try this:

 

1. Fly at 3 km

2. Throttle back at enter a shallow dive maintaining 500 km/h

3. Apply full throttle when altitude drops below 1 km

 

In the Fw-190 the power and RPM return immediately, after 1-2 seconds you have 3250 RPM. In the Bf-109 it takes 8-10 seconds for the prop to slowly adjust pitch to max RPM (2800). No other airplane in DCS has such sluggish prop pitch control.

It feels bit slow yes. I don't have any facts about correct speed in my hands however.

You must just anticipate it a bit, start to add revs before you pull out of dive etc and it's fine. Dora for example had much more advanced "Bediengerät", i believe this is why it have much faster prop pitch changes.

Maybe Yo-Yo can confirm it works correctly?

Hydrolic actuators for P-51 and Dora are faster than electric one in 109. But I found that this speed rate is very convenient for manual control.

Yo-Yo How much faster? ..You are you talking about milliseconds, or tenths of a second?

VDM airscrew electric pitch control system, was capable to change the blade pitch angle at 3 degrees per second. The Hamilton Standart change pitch at 4 degrees per seconds.

Hydrolic actuators for P-51 and Dora are faster than electric one in 109. But I found that this speed rate is very convenient for manual control.

yes for manual control, the 109 has just about the perfect speed....

BUT Yo-Yo, could you please reconsider the damage model for both the P51 and 109 in regards of prop pitch damage? especially the AI planes manage every time to kill it with 1 single shot out of ridiculous angles, distances, and even more annoying from what seems impossible,directly on your six i.e.

its like for the AI your whole plane is the prop pitch automation.

Yo-Yo How much faster? ..You are you talking about milliseconds, or tenths of a second?

VDM airscrew electric pitch control system, was capable to change the blade pitch angle at 3 degrees per second. The Hamilton Standart change pitch at 4 degrees per seconds.

Don't forget that in the 109, lower power also means lower rpm, so the prop is coarser than the equivalent CSP. So as well as being slower, it's got further to travel.

If you set the lever to idle it goes to fine pitch again because the automatics does not maintain rpm lower than cruise.

Yo-Yo takes in mind the windmilling effect?

If you cut throttle to idle, that does not mean that the engine lowers the speed to idle speed immediately. If a Bf-109 IRL is flying at high speed, and cut the throttle, windmilling effect keep the inertia of the propeller, and the pitch angle in VDM airscrew will not be reduced suddenly, otherwise in proportion to the turning speed.

Electric pitch control was almost perfect, only a little bit slower than the Hydraulic hydromatic pitch control system.

you must not forget that the Americans also used the Curtis electric propeller pitch control in his P-39, P-47, P-51A, P-38, F4F, etc,etc.

Funny numbers... do you have proof links to the ORIGINAL docs?

You can purchase all VDM electric propeller manuals in this page if you needed.

http://www.luftfahrt-archiv-hafner.de/vdm.htm

Link

page 43 of any use?