This packet contains learning modules designed for a self-paced course in aircraft environmental systems mechanics that was developed for the Air Force. Learning modules consist of some or all of the following materials: objectives, instructions, equipment, procedures, information sheets, handouts, workbooks, self-tests with answers, review section, tests, and response sheets. Topics covered in the learning modules are the following: air conditioning system, temperature control system, air supply, wiring, anti-icing system, maintenance management, inspection system, maintenance system, technical order system, aircraft hardware, Ohm's Law, series circuits, parallel circuits, series-parallel circuits, relays, DC motors, temperature-controlling bridge circuits, temperature control circuits wiring, alternating current, capacitance, inductance, AC motors, solid state devices, magnetic amplifiers, trainer aircraft air conditioning systems, decade resistors, fighter bleed air systems, temperature control panel, windshield temperature control circuit, rain removal system, and refrigeration system. (KC)