Bubi352
2nd Jun 2009, 21:24
After looking at the POH of a Cessna 172S NAVIII, I am having a little confusion with best power vs best economy. Maybe someone can shed the light on this for me.
First, when I look under section 5 of the POH - cruise performance - it says at the top under conditions "Recommended Lean Mixture At All Altitudes". Both best power and best economy are recommended lean techniques. This being said, I do not see anywhere on the POH how much fuel savings will I make if I used best economy versus best power. All it says is a 4% increase in range for a 3 knot penalty. Am I missing something?
Second, if I am at 65% best power or 65% best economy, are they any differences?
Finally, this is what confused me and that's also related to question #2. If I reached my cruising altitude and I start leaning for best economy. I can expect a change in RPM which will change my BHP. Do you increase back the RPM after leaning back to its original value to get back the loss in BHP or do you keep it the way it is?
First, when I look under section 5 of the POH - cruise performance - it says at the top under conditions "Recommended Lean Mixture At All Altitudes". Both best power and best economy are recommended lean techniques. This being said, I do not see anywhere on the POH how much fuel savings will I make if I used best economy versus best power. All it says is a 4% increase in range for a 3 knot penalty. Am I missing something?
Second, if I am at 65% best power or 65% best economy, are they any differences?
Finally, this is what confused me and that's also related to question #2. If I reached my cruising altitude and I start leaning for best economy. I can expect a change in RPM which will change my BHP. Do you increase back the RPM after leaning back to its original value to get back the loss in BHP or do you keep it the way it is?