DESCRIPTION AND OPERATION
A. The Electronic Flight Instrument System (EFIS) is one of five major subsystems of the Flight Management System (FMS). The other four major subsystems are: the Flight Management Computer System (FMCS), the Digital Flight Control System (DFCS), the autothrottle system (A/T), and the Inertial Reference System (IRS).
B. The EFIS provides displays for most of the airplane's navigational systems. The major displays provided by the EFIS are: color displays of pitch and roll; navigational maps; weather; radio altitude and decision height; and autopilot and flight path information. The EFIS also provides displays of: airspeed; ADF/VOR bearings; ILS data; and stall warning information.
C. AIRPLANES WITH OPERATIONAL TCAS; the EFIS also displays TCAS data.
D.The Electronic Flight Instrument system consists of the following components: two Symbol Generators (SGs), two Control Panels, two Electronic Attitude Director Indicators (EADIs), two Electronic Horizontal Situation Indicators (EHSIs), two Remote Light Sensors, an Electronic Flight Instrument (EFI) transfer switch, and two EFIS transfer relays (Fig. 1).
E. On airplanes with EFI/IRS switch annunciation, there are also two instrument transfer annunciator lights.
(1) The control panels for the captain and first officer are located on the left and right side of the aft electronic panel.
(2) The EADIs and EHSIs are located on captain's and first officer's instrument panels.
(3) The remote light sensors are mounted on the glareshield.
(4) The EFI transfer switch is located on the pilot's overhead panel.
(5) The instrument transfer annunciator lights are located on the captain's and first officer's instrument panels directly above the ALTITUDE ALERT light.
F. The source of attitude and heading data to the EFIS symbol generators can be selected using the IRS transfer switch on the pilot's overhead panel. The IRS transfer switch enables the operator to select IRS - L or IRS - R as the input system to an EFIS symbol generator.
G. A basic confidence test of the EFIS can be performed by pressing the TEST switch on the front of the EFIS symbol generator. In addition, the EFIS can be thoroughly checked using FMS BITE. The FMS BITE allows the EFIS to be checked for inflight faults, ground faults, current faults, and the status of the discretes associated with the system