Hi All,

can you advice me where to find a 912 ULS table stating the RPM / Manifold Pressure depending on altitude?

As far as I've understood the combination of RPM and MAP should change depending on altitude when you are driving a constant speed propeller.

Or am I wrong?



  • Re: Manifold pressure at different altitude

    by » 8 months ago

    The engine is not afraid of heights!  All that matters is the RPM and the MAP.

    Section 5 of the Operators manual shows that you can go WOT at 5500 and above, and anything goes as long as the MAP is below 26"

    Meaning that once you are above ~5000 ft., the skies the limit. 

    You could COARSE Up (Down) to 4000 rpm and WOT and still never be able to make much over 25".


    From the Manual...  5000rpm and 27.2" will produce 75% power.

    You could set the prop for 5000rpm and set the throttle to anything that keeps the MAP below 27.2.

    This would be doable at Sea level, but might not be possible even at WOT above 3000 ASL.


    Check out THIS thread.


    Bill Hertzel
    Rotax 912is
    North Ridgeville, OH, USA
    Clicking the "Thank You" is Always Appreciated.

You do not have permissions to reply to this topic.