Handling of STC's for Small Airplane Power Increase

by Bob Llewellyn
(Clifton, Quensland, Australia)

AC23-12 provides guidance on structural substantiation of Part 23 airplane modifications involving engine power increases. Is there any corresponding guidance on handling substantiation requirements?

ANSWER: I am not aware of any, but this question might be best answered by an engineering representative. Click here to download the DER Directory where you can find a list of Powerplant DER’s, or click here to locate an FAA Aircraft Certification Office nearest you.

AC 23-12 has been cancelled, so I am assuming that the information contained in that AC can be found in other guidance material published such as:

AC 23-13A – Fatigue, Fail-Safe, and Damage Tolerance Evaluation of Metallic Structure for Normal, Utility, Acrobatic, and Commuter Category Airplanes

AC23-16A – Powerplant Guide for Certification of FAR Part 23 Airplanes

AC 23-19A – Airframe Guide for Certification of FAR Part 23 Airplanes

AC23-21 – Airworthiness Compliance Checklists Used to Substantiate Major Alterations for Small Airplanes

You can download these Advisory Circulars at the FAA’s Website by clicking here.

FAA Order 8110.48 is also a good source of information about STC's for small aircraft. Click here to download FAA Order 8110.48