Description (AMM 34-42-01)

A-  The ground proximity warning computer (GPWC) is rack-mounted on shelf No. 4 of electronic equipment rack E2.  The GPWC consists of seven assemblies:  processor/memory, input/output, BITE display, FMC, power  supply, harness and chassis.            

B-  The computer receives glide slope deviation, barometric altitude rate,  radio altitude, gear and flap logic, airplane position and flight path   acceleration information from other airplane systems.  The input signals  are processed and signals are provided to warning devices if the airplane                 enters an unsafe flight path

The ground proximity warning system (GPWS) provides the pilots with aural and visual warning of potentially dangerous flight paths relative to the ground. The PWS processes signals from digital analog adaptor No. 1, VHF NAV receiver No. 1, radio altimeter No. 1, digital air data computer No. 1, inertial reference unit No. 1, digitial tall warning computers 1 and 2, flight  nagement computer, flap warning switches, anding gear logic shelf and the landing gear lever. The GPWS is operational when load control centers P18 and P6 are energized and the following system circuit breakers are closed: ground proximity warning, No. 1 air data, No. 1 VHF navigation, No. 1 inertial reference, No. 1 digital analog adapter, stall warning, flight management, flight interphone, and EFIS.