Cruise rpm

[JetPilot]

Since this is becomming a discussion, I did my research on this. First, after a pretty good search, there are ZERO publications limiting cruise of 912 engines below 5000 RPM. Second, there are several covering many RPM's, INCLUDING crusing below 5000 RPM. Here it is straight from the Rotax operators manual:

http://www.rotax-aircraft-engines.co...kus/d04670.pdf

Page 5-3 Revision April 01 2010

" RUN THE ENGINE ACCORDANCE WITH THE FOLLOWING TABLE "

They list RPM's of

5800 RPM
5500 RPM
5000 RPM
4800 RPM
4300 RPM

The graphs on the previous pages cover the full RPM range from 2500 to 5800 RPM.

There is a service letter Rotax SL-912-016 that warns against " HIGH ENGINE LOAD WITH LOW RPM " and a couple other things.

http://www.rotax-aircraft-engines.co...kus/d04670.pdf

http://www.rotax-aircraft-engines.co...kus/d04645.pdf

Everything in these recent Rotax publications agrees with what I said in my first post.

Mike