What effect does high density altitude, as compared to low density altitude, have on propeller efficiency and why?
A
Efficiency is increased due to less friction on the propeller blades.
B
Efficiency is reduced because the propeller exerts less force at high density altitudes than at low density altitudes.✓ Correct Answer
C
Efficiency is reduced due to the increased force of the propeller in the thinner air.
Explanation
At high density altitude the air is thinner, so the propeller, which works by accelerating a mass of air, has less air to act on and produces less thrust; PHAK Chapter 11 lists reduced propeller efficiency among the effects of high density altitude. Thin air does not make the propeller exert more force.
Related performance questions
(Refer to FAA-CT-8080-2H, Figure 38.) Determine the approximate landing ground roll distance. Pressu...(Refer to FAA-CT-8080-2H, Figure 38.) Determine the total distance required to land over a 50-foot o...(Refer to FAA-CT-8080-2H, Figure 35.) Determine the approximate manifold pressure setting with 2,450...(Refer to FAA-CT-8080-2H, Figure 8.) What is the effect of a temperature increase from 35 to 50°F on...(Refer to figure 8.) What is the effect of a temperature decrease and a pressure altitude increase o...
Keep practising
Study more FAA Private Pilot questions, or take a timed practice quiz.