Title: Explain environmental control in aircraft.
Course: Aircraft Pilot Training I (20053-I) > Section: Examining Aircraft Instruments, Components, Systems, and Performance

Explanation should include the following:

- Bleed air heating systems are used on turbine-engine aircraft.
- Extremely hot compressor bleed air is ducted into a chamber where it is mixed with ambient or re-circulated air to cool the air to a useable temperature.
- The air mixture is then ducted into the cabin.
- This type of system contains several safety features to include
  - temperature sensors that prevent excessive heat from entering the cabin
  - check valves to prevent a loss of compressor bleed air when starting the engine and when full power is required
  - engine sensors to eliminate the bleed system if the engine becomes inoperative.

PLT137