operational guidance
in 912 / 914 Technical Questions
8 years ago
I am buying a new plane with a Rotax engine and constant speed 3 blade prop. I have some very basic questions since I'm unfamiliar with high rev engines:
Propellers are efficient at low RPM, but engines bog down if they run too low RPM. Does Rotax have a recommendation table for RPM and FF or MP for fast, normal and econ cruise settings to help quantify the optimal combinations? For example, 4000RPM at full throttle would be legal, but both wasteful and harmful. I see no guidelines.
Does operating the engine at max continuous 5500 for long cruise, or at lower power settings for econ cruise have an effect on wear or engine reliability? Is there any wisdom in running the engine at lower RPMs?
My old TCM engine had tables for max, 75%, 65% and 55% rpm/MP/FF settings and I don't see that here. Could you tell me the values associated with those percentages for the 912ULS? Does Rotax consider those percentages useful as targets for normal, economy or loitering RPMs?
Thank you for any advice you can offer.
Propellers are efficient at low RPM, but engines bog down if they run too low RPM. Does Rotax have a recommendation table for RPM and FF or MP for fast, normal and econ cruise settings to help quantify the optimal combinations? For example, 4000RPM at full throttle would be legal, but both wasteful and harmful. I see no guidelines.
Does operating the engine at max continuous 5500 for long cruise, or at lower power settings for econ cruise have an effect on wear or engine reliability? Is there any wisdom in running the engine at lower RPMs?
My old TCM engine had tables for max, 75%, 65% and 55% rpm/MP/FF settings and I don't see that here. Could you tell me the values associated with those percentages for the 912ULS? Does Rotax consider those percentages useful as targets for normal, economy or loitering RPMs?
Thank you for any advice you can offer.
