This document outlines the engineering evaluation appropriate for modifying or replacing components of a previously certified seat when the certification process is based on qualification to the requirements of AS8049, which includes dynamic testing. The engineering evaluation presented in this document may be used to determine if a modification (including replacement of a component) is a minor change with respect to meeting the dynamic testing requirements described in AS8049. Whenever a modification is considered, the ability to meet all requirements of the applicable Federal Aviation Regulation (FAR) must be verified. For example, this would include the capability to meet requirements such as flammability and flotation. Analysis and/or test data supporting the ability of the new materials and/or configuration to meet the applicable requirements must be submitted with the change documentation.