This information report provides general guidance for the design considerations, qualification in endurance, strength and fatigue of landing gear using composite components as principle structural elements.

The information discussed herein includes the development and evaluation of design data considering: the potential for imbedded manufacturing defects, manufacturing process variations, the component operating environment, potential damage threats in service, rework and overhaul, and inspection processes.

This AIR mainly discusses the use of thick composites for landing gear structural components. Considerations and recommendations provided in this AIR may therefore differ greatly from considerations and recommendations found in widely accepted composite design references such as CMH-17 and Advisory Circulars such as AC 20-107(B).

Purpose

The purpose of this AIR is to provide general guidance in the qualification of composite components for landing gears. Compliance with this report is not considered approval for installation on any category aircraft or helicopter

The Certifying Authority for the platform for which the equipment is intended should be consulted for concurrence with the approaches proposed herein as an acceptable qualification demonstration for composite landing gear components.

Application

This AIR is applicable to the qualification of the composite landing gear structural elements in strength, fatigue and endurance. The current version of this document focuses on the use of Polymer Matrix Composites, but might also be applicable for other composite materials such as Metal Matrix Composites although they are not explicitly discussed herein.

Compliance with this information report by manufacturers, installers, and users may be used as a means of assuring that the equipment will have the minimum capability to satisfactorily perform its intended function(s).

Composite Design References

In the development of this AIR, close interaction is sought with other composite guideline development such as within the CMH-17 and AC 20-107 committees.

It should be noted that the majority of documentation on composite materials concerns thin walled structures. The application in landing gear principle structural element primarily focuses on thick walled structures.

Further development of this AIR

It is recognized that the guidance provided in this document on composite application to a landing gear principle structural element is general in nature and limited in scope. It is the intent that this document will be further developed over time where active feedback from industry and authority specialists is sought to expand the scope to other category aircraft and provide more specific guidance to composite component development in landing gear principle structural elements.