Honeywell MK VIII, MK XXII manual Description And Operation, General System Description

EGPWS LINE MAINTENANCE MANUAL

2 DESCRIPTION AND OPERATION

2.1 GENERAL SYSTEM DESCRIPTION

The purpose for the Enhanced Ground Proximity Warning System (EGPWS) is to help prevent accidents caused by Controlled Flight Into Terrain (CFIT), obstacles, or severe windshear. The Enhanced Ground Proximity Warning Computer (EGPWC) accepts a variety of aircraft sensors and system inputs and applies alerting algorithms to provide the flight crew with aural messages and visual annunciations when the boundaries of alerting envelopes are exceeded. A graphic depiction of terrain and obstacles within the range selected on an EFIS or Weather Radar display may be configured for enhanced situational awareness with respect to terrain and obstacles. Figure 2-1provides an overall system block diagram.

Figure 2-1: Enhanced Ground Proximity Warning System

The EGPWS is comprised of the following:

•Aircraft sensors and systems providing input signals

•The Enhanced Ground Proximity Warning Computer (EGPWC)

•Flight deck audio systems (speaker and interphone)

•Alert lamps and/or EFIS or EICAS displays (for alert and system status messages)

•EFIS Navigation Display (ND), Multi-Function Display (MFD), or Weather Radar Indicator for display of terrain

•Switching relay(s) when required for switching display inputs from weather display to terrain display

•GPS antenna for direct connection to EGPWC with internal GPS sensors

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