Pilot Exam Coach

US Private Pilot

Switch to Canada PSTAR
Radio communicationsQuestion 812 of 934

A pilot sets the wrong altimeter setting. How does this affect the altitude that the transponder sends to ATC?

  1. The transmitted altitude shifts by the same error
  2. The transponder stops sending altitude until the pilot corrects the altimeter setting
  3. It does not change the transmitted altitude, but changes the true altitude flown
  4. ATC receives the altitude corrected for the altimeter error
Show answer

Correct answer: It does not change the transmitted altitude, but changes the true altitude flown

Altitude encoders are preset to standard pressure. A wrong setting changes the true altitude flown, not the transmitted altitude.

Source: Aeronautical Information Manual (FAA, Basic with Change 3, 9 July 2026), AIM 4-1-20 Transponder and ADS-B Out Operation, page 223

Practice radio communications

Questions last reviewed: 18 October 2026