📘14 CFR §91.413 – ATC Transponder Tests and Inspections

🚩 Overview

ATC transponders enhance radar identification, position tracking, and safety. To ensure accuracy and reliability, the FAA mandates periodic transponder tests and inspections.

---

✅ Key Operational Requirements

📡 1. Required Tests and Inspections

• Transponders must be tested and inspected every 24 calendar months to ensure accurate operation and compliance with FAA standards.

🔧 2. Authorized Inspection Personnel

• Transponder tests and inspections must be performed by:

  • Certified repair stations.

  • Appropriately rated mechanics (holding necessary avionics or transponder certifications).

📋 3. Documentation

• Following each inspection, documentation must be entered in the aircraft’s maintenance logbooks, detailing:

  • Type of inspection.

  • Date performed.

  • Results of the test (Pass/Fail).

  • Identification and certification number of the authorized individual or repair station.

🚫 4. Operational Compliance

• Aircraft with transponders may not operate unless these required tests and inspections are current and properly documented.

---

🛩️ Example Scenario

You're preparing for a flight in Class C airspace, requiring an operable Mode C transponder. Before departing, confirm your aircraft’s transponder inspection was completed within the last 24 calendar months, verifying the logbook entries clearly show the inspection date, pass status, and inspector details.

---

📌 CFI Pro Tips

• Logbook Checks: Train students to habitually verify transponder inspection dates and records during their preflight planning, emphasizing their responsibility for compliance.

• Awareness and Compliance: Explain clearly how these inspections impact legal aircraft operation and the potential safety implications of non-compliance.

---

📚 Further Reading and Official References

• 14 CFR §91.413 (Full FAA Regulation): https://www.ecfr.gov/current/title-14/chapter-I/subchapter-F/part-91/subpart-E/section-91.413

• FAA Advisory Circular AC 43-6D (Transponder and Altimeter Tests): https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43-6D_CHG_1.pdf

• FAA Aeronautical Information Manual (AIM) – Transponder Operation: https://www.faa.gov/air_traffic/publications/atpubs/aim_html/chap4_section_1.html