FAA Commercial Pilot Airplane (CAX)RegulationsEasy
A commercial pilot is conducting a flight for compensation or hire. The aircraft is equipped with a transponder. When must this transponder be inspected and tested for proper operation?
- AOnly at the time of the annual inspection.
- BWithin the preceding 24 calendar months.
- CWithin the preceding 36 calendar months.
- DWithin the preceding 12 calendar months.
Show answer & explanationAnswer & explanation
Correct answer: B. Within the preceding 24 calendar months.
According to 14 CFR 91.413(a), no person may use an ATC transponder unless, within the preceding 24 calendar months, the transponder has been tested and inspected and found to comply with appendix F of part 43 of this chapter.
Why the other options are wrong
- A. While it can be done during an annual, it is a separate inspection requirement with its own 24-calendar-month interval, not tied solely to the annual.
- C. 36 calendar months is incorrect; there is no such interval for transponder inspections.
- D. 12 calendar months is the interval for annual inspections and ELT inspections, not transponders.
Transponder Inspection Interval
An ATC transponder must be inspected and tested for proper operation within the preceding 24 calendar months.
- Required every 24 calendar months.
- Ensures compliance with performance standards.
- Governed by 14 CFR 91.413.
Memory trick: Transponders get their check-up every two years, like a biennial health check.