Where is bleed air taken from on a turbine engine?

• A. From the turbine exhaust
• B. From the ambient inlet air
• C. From the final or highest pressure stage of the compressor
• D. From the engine oil cooler

Answer: (C)

Bleed air comes from the compressor section of a turbine engine. To get air at enough pressure for pneumatic systems (like starting, environmental control, and anti-ice), the air is taken from the discharge of the final, highest-pressure stage of the compressor. This location provides clean, high-pressure air that can later be cooled to a usable temperature before it’s sent to the aircraft systems. Tapping from the ambient inlet would be too low in pressure, from the turbine exhaust would introduce hot exhaust gases and contaminants, and from the engine oil cooler would contaminate the air with oil. Some engines also bleed from intermediate stages for specific operating conditions, but the high-pressure stage bleed is the typical source for required high-pressure airflow.