Multiengine Aerodynamics

Question 1

How is aircraft performance affected when an engine fails?

Answer 1

There is a loss of 50% of power which reduces climb performance by 80 to 90%.

Question 2

How is drag affected by a windmilling propeller?

Answer 2

At the smaller blade angles near the flat pitch position, the drag added by the propeller is large. A propeller windmilling at high speed in the low range of blade angles can produce parasite drag as great as the parasite drag of the entire airframe.

Question 3

How is drag affected by a feathered propeller?

Answer 3

When the propeller blade angle is in the feathered position, parasite drag from the propeller is at a minimum. In a typical multiengine airplane, the parasite drag from a single, feathered propeller is a small part the airplane’s total drag.