FAA Commercial Pilot Airplane (CAX)RegulationsEasy
A commercial pilot is conducting a flight for compensation or hire. The aircraft is equipped with a transponder. According to regulations, how often must the transponder be inspected and found to comply with 14 CFR Part 91, Appendix F?
- AAfter any major repair or alteration to the transponder system.
- BEvery 12 calendar months.
- CEvery 24 calendar months.
- DOnly when the aircraft is used for IFR operations in controlled airspace.
Show answer & explanationAnswer & explanation
Correct answer: C. Every 24 calendar months.
14 CFR 91.413(a) explicitly states that no person may use an ATC transponder unless it has been tested and inspected within the preceding 24 calendar months and found to comply with Appendix F of Part 43.
Why the other options are wrong
- A. While a major repair/alteration might necessitate re-inspection, the 24-calendar-month interval is a standing requirement regardless.
- B. This is the interval for the altimeter and static system inspection, not the transponder.
- D. The transponder inspection interval is not dependent on specific operational use, but rather a calendar requirement for its functionality.
Transponder Inspection Interval
An ATC transponder must be inspected and found to comply with 14 CFR Part 91, Appendix F, within the preceding 24 calendar months.
- Required for all aircraft using an ATC transponder.
- Interval is 24 calendar months.
- Must comply with Part 43, Appendix F.
Memory trick: Two years for the transponder, two years for its squawk.