Instrument Displays and Integration: EFIS, EICAS/ECAM and Standby Instruments
EFIS
An electronic flight instrument system replaces mechanical attitude, heading, airspeed and altitude displays with CRT or LCD screens. Typical layout: a primary flight display (PFD) in front of each pilot, showing attitude, flight director, airspeed, altitude, vertical speed, heading and navigation data; a navigation display (ND) showing route, weather and traffic. A symbol generator (display computer) drives the displays; a failure degrades to reversionary modes or to the standby instruments.
EICAS/ECAM
Engine indication and crew alerting systems (EICAS, ECAM) present engine parameters, system synoptics and alert messages. Understand the hierarchy: warning (red, immediate action), caution (amber, timely action), advisory (white/green, information). Messages may be suppressed in some phases (e.g. inhibit during take-off) to avoid distraction at critical times.
Glass cockpit and standby instruments
Modern flight decks integrate the flight management system, autopilot, autothrottle and displays. Electronic standby instruments (ESI) provide attitude, airspeed and altitude independent of the main symbol generators, usually with their own battery. Know the reversionary panel and how to select alternate display sources.
Traps
Questions may ask which display is lost when a symbol generator fails, or what remains available on the standby instrument. Remember that standby instruments have separate power and sensors - that is their purpose. Also know that alert inhibition during take-off does not mean the system is inoperative.
Worked example
If the captain's PFD fails, the usual response is to select the reversionary mode so that the remaining display shows the essential data, then refer to the standby instruments and QRH procedure. The first officer's PFD continues to operate normally.