Aiki_Aviator
Well Known Member
I have recently spent a day with a LAME covering of the 100 hourly engine maintenance schedule and processes and part of this was the adjusting of the mixture.
The item that arose was that the correct adjusting of the mixture was achieved through setting the engine to idle (i.e. approx 650 RPM for the IO-540) and then upon setting mixture to cutoff the RPM should rise between 30-50 RPM before shutting down.
This was all good, however I was wondering is there any reason that we set the RPM on shut down to approx 1200RPM for normal operations before shutting mixture rather than to idle? I have not found any reason for this other than convention.
Given we have the ability to use engine monitoring like saavyanalysis which would correctly monitor the shut down RPM, we could have this information available and the mixture adjusted into the correct range very easily without needing to subject the engine to ground running and multiple restarts if we just shut the engine down on idle and noted the RPM outputs over time with minor adjustments as we went along.
Any thoughts and information welcome.
The item that arose was that the correct adjusting of the mixture was achieved through setting the engine to idle (i.e. approx 650 RPM for the IO-540) and then upon setting mixture to cutoff the RPM should rise between 30-50 RPM before shutting down.
This was all good, however I was wondering is there any reason that we set the RPM on shut down to approx 1200RPM for normal operations before shutting mixture rather than to idle? I have not found any reason for this other than convention.
Given we have the ability to use engine monitoring like saavyanalysis which would correctly monitor the shut down RPM, we could have this information available and the mixture adjusted into the correct range very easily without needing to subject the engine to ground running and multiple restarts if we just shut the engine down on idle and noted the RPM outputs over time with minor adjustments as we went along.
Any thoughts and information welcome.