Question

Stick fixed neutral point is defined at 40% of chord. Choose appropriate location of Stick free neutral point.

(a) 0.39

(b) 0.8

(c) 0.65

(d) 0.5

I have been asked this question in class test.

Question is taken from Stick-Free Stability in division Stability, Control, and Handling Qualities of Aircraft Design

Answer 1

The correct option is (a) 0.39

To elaborate: Typically, stick free neutral point is located at 2-5% ahead of stick fixed neutral point.

Stick free neutral point = 2 to 5 % ahead of stick fixed = 0.02*0.4 to 0.05*0.4 ahead of stick fixed = 0.008 to 0.1 ahead of stick fixed neutral point

Hence, neutral point location of stick free = 0.4-(0.008 to 0.1) = 0.392 to 0.39.

Hence, Correct answer from the given options Will be 0.39.