As the altitude (OK, technically not the MSL but the pressure-altitude) increases the air get thinner at the power the engine can produce at a given RPM is lower... despite the carbs trying to compensate and get the right mixture as the altitude changes... and I'll have a lower indicated airspeed at the same throttle setting than at a lower altitude.
On other other hand air resistance (drag) is less, and, for example, at 8500 feet an accurate indicated airspeed of 100mph results in a true airspeed of of about 113mph.
So I will be traveling further in an hour of fuel consumption than at a lower altitude.
So is there an approximate altitude where the gain of true airspeed due to altitude with a Rotax 912 gets you the most miles per gallon?
For example, it's known the sweet spot on altitude efficiency for jet engines is about 35,000 feet, for turboprops (if I got this right) it's about 25,000 feet.
Any idea where it is for an aircraft powered by a Rotax 912?
A.
On other other hand air resistance (drag) is less, and, for example, at 8500 feet an accurate indicated airspeed of 100mph results in a true airspeed of of about 113mph.
So I will be traveling further in an hour of fuel consumption than at a lower altitude.
So is there an approximate altitude where the gain of true airspeed due to altitude with a Rotax 912 gets you the most miles per gallon?
For example, it's known the sweet spot on altitude efficiency for jet engines is about 35,000 feet, for turboprops (if I got this right) it's about 25,000 feet.
Any idea where it is for an aircraft powered by a Rotax 912?
A.
