Inspectability Criteria for Airframes Designed to Fatigue/Fail-Safe Requirements

This paper covers inspection programs which will become a part of small airplane certification and operation as a result of Amendment 7 to FAR 23. Amendment 7 adds fatigue evaluation to wings and associated structure, reference paragraph 23.572.

Paragraph 23.572 allows two basic methods of providing the required fatigue evaluation fatigue strength investigation or fail-safe strength investigation.

The fail-safe strength investigation allows compliance with the regulations without running long and expensive fatigue analyses and/or tests but must be supplemented with proper inspections for complete FAR 23 compliance. Designing for inspectability and inspection methods will be covered.