Question

The Free Elevator Factor (FEF) primarily indicates

• A. The reduction in stick-free longitudinal stability compared to stick-fixed stability
• B. The increase in elevator deflection due to pilot input
• C. The maximum nose-up trim angle of the aircraft
• D. The ratio of tail lift to wing lift

Hint:

Generally, \[ \boxed{ \text{Stick-fixed stability} > \text{Stick-free stability}. } \] The Free Elevator Factor accounts for the reduction in stability caused by the elevator floating freely under aerodynamic loads.

Answer 1

The Correct Option is A

Step 1: Recall the meaning of Free Elevator Factor (FEF). When the elevator is free to float, the longitudinal stability of the aircraft decreases compared to the stick-fixed condition. The Free Elevator Factor (FEF) is used to account for this reduction in stability.

Step 2: Identify the correct statement. The Free Elevator Factor primarily represents \[ \boxed{ \text{the reduction in stick-free longitudinal stability compared to stick-fixed stability.} } \] Therefore, \[ \boxed{\text{Option (A)}} \] is correct. Thus, \[ \boxed{(A)} \] is the correct answer.