Trying to understand the MBG

[xvii-Dietrich]

In the FW 190 D-9, there is a MBG (Motorbediengerät) emergency handle. It is red, and labelled with "Notzug für Bedien-Getr.".

 

According to the DCS FW 190 D-9 manual (page 68... sorry, I couldn't find a version number on the document to report), it states:

 

This handle is connected via cable to the aircraft’s "Motorbediengerät" (MBG). In normal position the MBG operates in automatic mode. In case of emergency, the handle can be pulled to allow the engine to operate at higher boost pressure than normal.

If at all possible, the handle should be pulled when the throttle is in Idle setting.

Speed control remains automatic.

Please take extra care to watch engine speed and boost. The engine must be loaded only as far as absolutely necessary in "Notzug" mode.

When flying in "Notzug" mode, boost pressure of 1.55 ATA should never be exceeded!

When flying in "Notzug" mode, engine speed of 2,700 RPM should never be exceeded!

Now, if I use the MBG handle, it seems to make no difference to my speed. For example:

 

Throttle   ATA   RPM   MBG   Speed km/h
 ~90%    1.37  3000   off    ~565
 ~90%    1.71  3000    on    ~565
 100%    1.92  3250   off    ~590
  100%    1.95  3250    on    ~590

Tests were done in level flight at low altitude, with the aircraft trimmed as carefully as possible. In all cases, the MW50 was switched on and there was good MW50 pressure.

 

While the ATA certainly jumps up when the MBG handle is pulled out, I am experiencing no change in aircraft speed and the RPM remains the same.

 

Also, the manual says never to exceed ATA 1.55 and RPM 2700. But... I fly at RPM 3000 without any problems.

 

 

I've also checked these threads:

 

 

https://forums.eagle.ru/showthread.php?t=128818

 

https://forums.eagle.ru/showthread.php?t=134922

 

 

 

But they a) seem old and b) again report RPMs that are quite low compared to what I use normally. They also don't really answer the MBG question.

 

 

 

 

 

 

 

So, could someone please explain how the MBG is supposed to be used, and what I should be doing if I want to get maximum speed (even if only temporarily) in level flight? Thanks.

[rogonaut]

want to know too :)

[saburo_cz]

I always thought that this handle, "Notzug für Bedien-Getr.", should be pull only when emergency situation occurs, when MBG (Motorbediengerät) fails or is damaged.

 

When I pull it, I will lost automatic engine regulation and will control engine like with "throtle lever conected with propeller RPM control lever" directly without any fine tuning according to temperature, altitude/pressure(s) and etc.

Just because I will cut off MBG that way.

And that is why there are these low limits for engine running with lever pulled...

[Flying-Kane]

Hi gents,

 

saburo is right. Pull the handle when the MBG is damaged and the automatic regulation is out of order.

 

You can find it in the german Luftwaffe engine manual of the Jumo 213A-1.