Audemus, Inc.

FAA 91.411 & 91.413 Aircraft Inspections

What Are 91.411 and 91.413 Inspections?

These are two important FAA regulations that require regular testing of key systems on your aircraft.

14 CFR 91.411 – Altimeter and Static System Inspection

This regulation requires that your aircraft’s altimeter (the instrument that tells you how high you’re flying) and the static pressure system (the small ports and tubes on the outside of the plane that measure air pressure) be tested for accuracy every 24 months. It also checks the device that automatically sends your altitude to air traffic control. If you fly on instruments or in controlled airspace, this inspection is required to stay legal.

14 CFR 91.413 – Transponder Inspection

This regulation requires testing of your aircraft’s transponder — the electronic box that makes your plane visible on radar and tells controllers who you are and how high you’re flying. It must also be inspected every 24 months. The check ensures your transponder is working properly and sending accurate information to air traffic control.

Why These Matter

These two inspections work together to make sure your plane is correctly reporting its altitude and identity. Accurate altitude information is critical for safety — it helps prevent mid-air collisions and allows air traffic controllers to safely guide aircraft. Without current 91.411 and 91.413 certifications, most aircraft cannot legally fly under instrument rules or in busy controlled airspace.

Our Part 145 Repair Station performs both of these required inspections using properly calibrated equipment in full compliance with FAA standards.