27 Dec What is EFIS
Electronic Flight Instrument Systems (EFIS) were developed in an effort to improve the safety and operation of complex and complicated computer systems and controls aboard aircrafts.
These systems aid in reducing user error, reduce risks of misinterpretation of data, and aid with focusing a pilot’s attention on those matters requiring immediate attention or priority.
Also known as a ‘flight deck’, an EFIS is in essence an instrument display system using digital technology as opposed to manual or electromechanical feedback and measurements.
The majority of EFIS systems are comprised of what is known as a PFD, or primary flight display, an EAD, or electronic attitude direction indicator, and lastly, an EHSI or electronic horizontal situation indicator.
Primary Flight Display (PFD)
A Primary Flight Display, as the name suggests, is the main instrument display system referenced most often by the pilot for flight-relevant information. Although layouts vary based on make and model, the display unit generally combines several flight parameters and measurements into a centralized display to enhance focus and situational awareness.
Conventionally, the center of a PFD is comprised of a central altitude indicator (AI) and flight detector, with vertical speed references on the right, along with vertical deviation indicators. A compass reference is usually positioned at the bottom, with autothrottle and/or autopilot positioned across the top of the instrument panel.
Electronic Attitude Direction Indicator (EAD)
Originating as a ‘gyro horizon’ or ‘artificial horizon’, the modern attitude indicator (AI) is an in-flight instrument display that provides the pilot with information regarding the orientation of the aircraft in relation to the Earth’s horizon.
On display is a small digital replica of the aircraft, mimicking the actual aircrafts position relative to the horizon, and is commonly used during low visibility or other meteorological flight conditions. On the EAD display, attitude is communicated in a unit of degrees.
Electronic Horizontal Situation Indicator (EHSI)
The electronic horizontal situation indicator (EHSI) aims at delivering directional information with the use of two intuitive navigational aids that provide the pilot with vital information regarding the heading of the aircraft.
In concert with the PFD, the EHSI commonly is used to display relevant information in ILS, VOR, MAP and PLAN modes.
PLAN – displays a fixed map of the selected flight plan
MAP – displays the aircraft’s flight against the backdrop of a moving map in real-time. The MAP also displays both inactive and active navigational aids, in addition to known airports, waypoints and weather radar information (if selected) to be displayed in the background.
Some EHSIs may also provide information depicting air traffic, distance and arrival times, wind direction and speed, heading flown, ground speed, and other useful information.
Electronic Flight Instrument Systems (EFIS) – a critical tool for pilots
Historically, in-flight instrumentation was electromechanical and displayed across a dashboard with various individual instruments. Today, modern PFDs are digitalized and computerized, offering a more robust, feature-rich, intuitive, and easy to interpret and manage display of information useful for pilot navigation and safety.
These displays improve in-flight operation, reduce the chance of pilot error, and enable more efficient use of information.