Avionics displays
EFIS and Pilot/Flight Deck Interfaces
The layout, controls, displays and amount of automation in flight decks have evolved
tremendously in commercial aviation. What is sometimes termed the "classic" flight deck, which includes the
B-727, the DC-10, and early series B-747, is typically characterized by dedicated flight displays, where one
piece of data is generally shown on a dedicated gauge or dial as the form of display. These aircraft are
relatively lacking in automation. All of these aircraft are further characterized by the relative simplicity
of their autopilot, which offers one or a few simple modes in each axis. In general, a single instrument
indicates the parameter of a single sensor. In a few cases, such as the Horizontal Situation Indicator, a
single instrument indicates the "raw" output of multiple sensors. Regardless, the crew is generally
responsible for monitoring the various instruments and realizing when a parameter is out of range. A simple
caution and warning system exists, but it covers only the most critical system failures.
The first generation of "glass cockpit" flight decks, which include the B-757/767,
A-310, and MD-88, receive their nickname due to their use of cathode ray tubes (CRTs). A mix of CRTs and
instruments was used in this generation of flight deck, with instruments used for primary flight information
such as airspeed and altitude. EFIS installations have the following components:
displays, controls and data processors. A key innovation in these flight decks was the
"map display" and its coupling to the Flight Management Systems (FMS). This enabled the crew to program their
flight plan into a computer and see their planned track along the ground, with associated waypoints, on the
map display. Accompanying the introduction of the map display and FMS were more complex autopilots (added
modes from the FMS and other requirements). This generation of aircraft also featured the introduction of an
integrated Caution and Warning System, usually displayed in a centre CRT with engine information. A major
feature of this Caution and Warning System was that it prioritized alerts according a strict hierarchy of
"warnings" (immediate crew action required), "cautions" (immediate crew awareness and future action
required), and "advisories" (crew awareness and possible action required)."
Electronic flight instrument systems
The second generation of "glass cockpit" flight decks, which include the B-747-400,
A-320/330/340, F70/100, MD-11, and B-777, are characterized by the prevalence of CRTs (or LCDs in the case of
the B-777) on the primary instrument panel. CRT/LCDs are used for all primary flight information, which is
integrated on a few displays. In this generation of flight deck, there is some integration of the FMS and
autopilot - certain pilot commands can be input into either the FMS or autopilot and automatically routed to
the other.
Primary Flight Displays PFDs and secondary flight displays SFDS
There are varying levels of aircraft systems automation in this generation of flight
deck. For example, the MD-11 fuel system can suffer certain failures and take corrective action - the crew is
only notified if they must take some action or if the failure affects aircraft performance. The caution and
warning systems in this generation of flight decks are sometimes accompanied by synoptic displays that
graphically indicate problems. Some of these flight decks feature fly-by-wire control systems - in the case
of the A320/330/340, this capability has allowed the manufacturer to tailor the control laws such that the
flying qualities of these various size aircraft appear similar to pilots. The latest addition to this
generation of flight decks, the B-777, has incorporated "cursor control" for certain displays, allowing the
flight crew to use a touchpad to interact with "soft buttons" programmed on these flight displays.
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