MIL-STD-2218, MILITARY STANDARD: THERMAL DESIGN, ANALYSIS, AND TEST PROCEDURES FOR AIRBORNE ELECTRONIC EQUIPMENT (20 MAY 1992) [SUPERSEDING MIL-T-23103]., This standard establishes requirements for thermal design and cooling analyses, thermal design verification tests, and preproduction qualification tests for airborne electronic equipment. These thermal design requirements are provided to ensure that the equipment will operate satisfactorily without manual adjustment under any mode of operation in the aircraft. It also establishes guidelines for test methods for verification testing of the thermal and cooling design and preproduction qualification temperature and humidity tests to ensure that the equipment meets its performance requirements and reliability criteria. This document defines a thermal design process establishing and validating the following: a. Equipment cooling methods and coolant flow requirements. b. Allowable component temperature and component power, based on derating requirements to achieve lowest component temperatures consistent with reliability and life cycle cost (LCC) requirements. c. A thermal design analysis which defines the temperatures, heat sources, heat paths and heat sinks of all temperature critical components for worst-case power, environmental temperature-altitude and coolant flow (where applicable) conditions. d. Thermal design, verification and preproduction qualification tests.