34-26-00  ELECTRONIC FLIGHT INSTRUMENT SYSTEM Back

A. System Function

The Electronic Flight Instrument System (EFIS) gives the flight crew the primary display of:
  • Attitude and heading
  • Airspeed, Vertical speed and altitude
  • Flight Director (FD) modes and flight guidance commands
  • Navigation data
The display and remote controllers let the flight crew set as applicable the course, heading, airspeed and attitude of the aircraft (to fly the aircraft to a set flight path).

B. System Components

The primary components of the system are the:
  • Two Electronic Horizon Situation Indicators (EHSI) (Ref. Fig. 2)
  • Two Electronic Attitude Director Indicators (EADI) (Ref. Fig. 2)
  • Two Symbol Generators (SG) (Ref. Fig. 3)
  • Two display controllers (Ref. Fig. 1)
  • Two remote controllers (Ref. Fig. 1)

C. System Operation

Each SG gets input data from the related aircraft systems and changes the data into video and deflection signals. The SG sends the video and deflection signals to the EHSL and EADI to give the displays. An Avionics-Standard Communications Bus (ASCB) gives communication between each SG for cross-side data switch operation and comparison monitor fucntions.

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