This document provides guidelines for the process used to establish the equivalency of TTE and related procedures other than that recommended by the OEM. Figure 1 is provided to assist in establishing when an equivalency determination is necessary. Primarily, this report is concerned with equipment specified or recommended for the purpose of performing specific tasks concerning the airworthiness of an article (e.g., avionics, hydraulics, pneumatics, mechanical devices, etc.). However, this process may be used to establish the equivalency to any OEM-recommended tool or device. In those instances where the airline or repair station uses the OEM recommended equipment, no proof of equivalency is necessary.

Purpose of the Document

The goals of ARINC 668 are:

• To provide uniform guidance for airlines and repair stations in developing their processes and documentation for determining functional equivalency of TTE and related procedures used in maintaining aircraft and their associated components. This applies to both generic and application specific equipment.

• To define the roles and responsibilities for the organizations involved.

TTE is defined as any tooling, test apparatus, or other device that provides a means of testing, measuring, or aiding in maintaining aircraft or components during maintenance procedures as outlined and required by a controlling document.