Altimeter and Transponder Certification

For VFR operations, the FAA requires (FAR 91.413) all transponder-equipped aircraft to be inspected every two years to verify the proper operation of the transponder and associated altitude-reporting equipment. Transponders systems that don't meet minimum requirements and are out of alignment can cause significant problems with ATC radar systems, including incorrect altitude readout, duplicate targets or no target at all. The tests are fairly simple and can be performed on the ramp in about 30 minutes. FAR 43, Appendix F, describes the transponder inspection requirements.

In addition to the transponder tests described above, IFR aircraft are required (FAR 91.411) to have their altimeter and static system inspected and certified every two years. These tests are more involved and usually requires the removal of the altimeter and altitude encoder for bench testing and adjustment. The altimeter is subjected to a series of tests to insure it meets the minimum requirements for accuracy and repeatability. The altitude encoder is checked against the primary altimeter and adjusted as required to insure data correspondance. After the equipment has been inspected and reinstalled in the aircraft, a static system leak check is performed. Leaks in the static system can cause significant errors in the altitude reporting equipment and are sometimes difficult to locate. FAR 43, Appendix E, describes the altimeter system inspection requirements.

Ferrer Aviation Services, LLC, is authorized by the FAA to perform these tests at your location.

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