Descent Power Settings

[BaBene 0]

Hi,

 

I was wondering why the AFE sets the power settings of the plane to 26" MAP and 2200 RPM. I couldn't find a recommendation in the POH. Using this settings it is kind of hard to lose altitude and / or speed in level flight. The 26" MAP seems to be a little bit high for my taste, is it okay to reduce this? What is the minimum manifold pressure? Can I reduce the thrust to idle? What is the reasoning behind this high manifold pressure setting?

 

Any answer would be appreciated

 

Best regards,

 

Benjamin Isbarn

[downscc 1,327]

What is the reasoning behind this high manifold pressure setting?

 

Don't forget that these are geared engines, if you allow the prop to turn the engine instead of engine turning prop you are going to have serious repair costs.  You have to stay way ahead of this airplane, descent planning is an art that takes hours to learn.

 

I'm pretty sure this power setting is what was recommended by one of the DC-6 pilots on the testing team.

[scandinavian13 5,192]

 

 

The 26" MAP seems to be a little bit high for my taste, is it okay to reduce this?

 

If you like buying new engines...

 

The weather isn't to my taste on Monday, but certain parts of life you have to just accept and deal with.

 

 

 

What is the minimum manifold pressure?

 

Wonder why we chose 26 inches...?  :wink:

 

In all seriousness, the main factor you want to watch is that you're providing positive thrust. An indication on the BMEP gauge is a good start.

 

 

 

Can I reduce the thrust to idle?

 

On very short final, sure. Before that? Really not a good idea.

 

Have a read here:

http://www.douglasdc3.com/sohn/3.htm