AIR - GENERAL - DESCRIPTION AND OPERATION

** ON A/C NOT FOR ALL

1. General

The air system includes primary, secondary (bypass) and parasitic (cooling and pressurizing) airflows and the systems used to control the airflow.

A. Engine Section
The airstream that flows through the engine supplies the propulsion airflow (secondary and primary airflow) or the ambient air to the air systems.

(1) Engine anti-icing (Ref. AMM D/O 75-10-00-00).

(2) Cooling (Ref. AMM D/O 75-20-00-00):

(a) High Pressure Turbine (HPT) Active Clearance Control (ACC) system (Ref. AMM D/O 75-21-00-00).

(b) Low Pressure Turbine (LPT) Active Clearance Control (ACC) system (Ref. AMM D/O 75-22-00-00).

(d) Electronic Engine Control (EEC) cooling blower system (Ref. AMM D/O 75-24-00-00).

(3) Engine Control

(a) Variable Bleed Valve (VBV) system (Ref. AMM D/O 75-31-00-00).

(b) Variable Stator Vane (VSV) system (Ref. AMM D/O 75-32-00-00).

B. Nacelle Section
The nacelle section supplies cooling and ventilation air for engine accessories installed along the fan and core casing. The distribution and circulation of the air makes sure that the components do not exceed their temperature limits.

[Rev.10 from 2021] 2026.04.01 03:13:57 UTC