Definition
The natural behavior of a system, such as an aircraft or control surface, after a disturbance, when no further input is applied. The system is left to respond on its own, and how it returns to (or fails to return to) its original condition reveals its stability characteristics.
Plain English
What happens to an aircraft on its own after you nudge it and then let go. You stop providing input and watch how it behaves by itself.
Context Anchor
Seen in aircraft stability and control discussions, especially when describing how an airplane behaves after turbulence or after the pilot releases a control pressure.
Derivation
From 'free' (released, without restraint) and 'response' (reaction). Together: the reaction of a system that has been released from input and is reacting on its own.
Why Pilots Care
Reveals whether the pilot truly understands the material rather than simply recognizing correct answers.
Intuition Check
Free response does not mean a spoken answer or a pilot answering in their own words. Here, “free” means the aircraft is reacting on its own after the original disturbance, with no continued input.
Example Sentence 1
After displacing the elevator and releasing it, the instructor asked the student to observe the aircraft's free response to see whether it returned to level flight.
Example Sentence 2
Practice tests with free response items helped the student prepare for the oral exam portion of the checkride.