21 - AIR CONDITIONING
- 21-00 AIR CONDITIONING - GENERAL
- 21-21 AIR DISTRIBUTION AND RECIRCULATION
- 21-23 LAVATORY/GALLEY VENTILATION
- 21-26 AVIONICS EQUIPMENT VENTILATION
- 21-28 CARGO COMPARTMENT VENTILATION
- 21-31 PRESSURE CONTROL AND MONITORING
- 21-41 COCKPIT AIR HEATING
- 21-43 CARGO COMPARTMENT HEATING
- 21-50 AIR COOLING
- 21-51 FLOW CONTROL AND INDICATING
- 21-55 EMERGENCY RAM AIR INLET
- 21-58 CONDITIONED SERVICE AIR SYSTEM (CSAS)
- 21-61 PACK TEMPERATURE CONTROL
- 21-63 COCKPIT AND CABIN TEMPERATURE CONTROL