How often must an ATC transponder system be certified?

How often must an ATC transponder system be certified?

• A. Every 12 calendar months
• B. Every 18 calendar months
• C. Every 5 years
• D. Every 24 calendar months

Answer: (D)

ATC transponder certification is about confirming the transponder and its altitude reporting work reliably under radar interrogation. The standard interval is every 24 calendar months. This cadence keeps the unit checked for proper responses to Mode A/C/S interrogations, accurate altitude encoding, and overall electrical and antenna if issues that could affect surveillance. The other intervals don’t match the regulatory requirement, so they’re not the correct cadence. Therefore, the required certification is every 24 calendar months.

ATC transponder certification is about confirming the transponder and its altitude reporting work reliably under radar interrogation. The standard interval is every 24 calendar months. This cadence keeps the unit checked for proper responses to Mode A/C/S interrogations, accurate altitude encoding, and overall electrical and antenna if issues that could affect surveillance. The other intervals don’t match the regulatory requirement, so they’re not the correct cadence. Therefore, the required certification is every 24 calendar months.