EXTERNAL GEARBOX MODULE The external gearbox module is an aluminum alloy casting. It is installed below the LP compressor case. The gearbox transmits power from the engine to drive the accessories mounted on the gearbox front and rear faces. During starting, the gearbox also transmits power from the air starter motor to the engine. The components installed on the forward face are: - pneumatic starter - EEC dedicated alternator- centrifugal breather assembly - hydraulic pump number 1 The components installed on the rear face are: - Integrated Drive Generator (IDG) - input drive bevel gears - oil pump - fuel pump- hydraulic pump number 2NOTE: for maintenance purposes, hand turning of the HP rotor system is achieved through the centrifugal breather assembly.