This specification prescribes structural requirements that apply to all portions of the airframe regardless of component, system, or structure. The applicant for a design approval must seek individual guidance from their respective civil aviation authority (CAA) body concerning the use of this specification as part of a certification plan.

The structural requirements described in this specification cover strength (loads, factor of safety, strength and deformation, proof of structure, vibration and buffeting, canard or tandem wing configurations, windshields and windows, landing gear, testing of wings and control surfaces, pressurization tests); mass and mass distribution (load distribution limits, leveling means; materials, processes, and methods of fabrication (materials and workmanship, fabrication methods, material strength properties and design values; and protection of structure (fasteners, accessibility provisions, fire protection of engine mounts, and other flight structure). Also addressed are special factors of safety, including casting factors, bearing factors, fitting factors, and configuration based factors.

1.1 This specification addresses the structural requirements that apply to all portions of the airframe regardless of component, system, or structure.

1.2 This specification was originally conceived for small airplanes as defined in the F44 terminology standard but may find broader applicability. Use of the term aircraft throughout this specification is intended to allow the relevant CAA(s) to accept this standard as a means of compliance as they determine it to be appropriate, whether for small airplanes or for other types of aircraft.

1.3 The applicant for a design approval must seek individual guidance from their respective CAA body concerning the use of this standard as part of a certification plan. For information on which CAA regulatory bodies have accepted this standard (in whole or in part) as a means of compliance to their Small Airplane Airworthiness Rules (hereinafter referred to as “the Rules”), refer to ASTM F44 webpage (www.ASTM.org/COMMITTEE/F44.htm) which includes CAA website links.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.