An electronic flight instrument system (EFIS) is a flight deck instrument display systemlocated at the flight cockpit in the lower deck after the windshield. It is poweredelectronically and produce digital output. The electronic display unit system consists of 3 different display units, the PrimaryFlight Display(PFD), Navigational Display(ND) and EICAS / ECAM based on theengine manufacturer.
There is one PFD and ND each for the first officer and captain.However, the EICAS/ECAM are shared between both crews. EFIS installations vary greatly. A light aircraft might be equipped with one display unit,displayed flight and navigation data whereas a wide-body aircraft is likely to have sixor more display units. Purpose of Electronic Flight Instrument System (EFIS) The purpose of an Electronic Flight Instrument System (EFIS) in an aircraft is todisplay output flight data in a CRT or LCD screen to monitor the progress of theaircraft’s flight and the correct function of all aircraft’s parts and system.
As well asdisplay essential information to aid the flight crew to operate the aircraft in a safe andefficient way. The EFIS units aid the pilot in controlling of the aircraft and making decision duringflight to the intended destination, by providing the flight information and navigationalinformation of the flight performance. Operations and functions of each unit of EFIS 1. AirDataInertialreferenceunit The inertial reference unit is connected to the aircraftsensors all around the aircraft to produce flight and airdata. The sensors include pitot static tube and ring lasergyroscope.
The whole system can be split into 2 units,the air data unit and inertial reference unit. In the airdata unit, the pitot static tubes are used with air datamodules to convert air pressure into electrical signalmagnitudes to the Inertial reference unit through databuses. With the calculation of Airspeed, Mach number,temperature and barometric pressure altitude. The AirData Inertial reference unit then compiles theinformation and process it to send to the next phase todisplay the result. 2. Navigationaldata Navigational Data is a common block of data that gives navigational information toguide the aircraft to reach the intended destination safely and efficiently throughavailable or decided routes and communication.
Normally, updated every 28 daysfor its contents to be current. The data taken from different sensors and instrumentsaround the aircraft. Such as weather radars, transponders, and etc. The navigationdata consist of the weather data, instrument landing system data, flight path data,traffic collision alerting system data, and etc, which aids the aircraft to navigatesproperly.
3. EFISControlPanel EFIS control panel helps to give manual control to the pilot to select the settingsand control the displays by choosing what information to be displayed in the CRTor LCD displays. They provide the pilots with the controls to the displays such asbrightness, range and mode settings in maps and to show preferred data and toenter data. 4. PrimaryFlightdisplay(PFD) A primary flight displays (PFD) is an instrument dedicated to flight information. It isa representation of “steam gauge” instruments, combined on one compact display,to help simplifying the pilot’s workflow and streamlining cockpit layouts. Theflexibility in the system makes it possible to display at any given moment only theinformation required for the present flight phase. 5.
Navigationdisplay(ND) The navigation displays (ND) displays navigational and weather information frommultiple systems. The second display on each pilot’s main instrument panel cannow be used for to replace the conventional Horizontal Situation Indicator (HSI) toa Navigation Display (ND). the aircrew can overlay different information over a mapor chart. The ND overlay information such as the aircraft’s current route plan,weather information from either on-board radar or lightning detection sensors orground-based sensors, restricted airspace and aircraft traffic. It can be used toview other non-overlay type of data such as current route plan and calculatedoverlay-type data such as the glide radius of the aircraft, the given current locationover terrain, winds, and aircraft speed and altitude.
ND can also display informationabout aircraft systems, such as fuel and electrical systems and changes the colouror shape of the data to alert the aircrew of hazardous situations. Pilots have five modes of presentation 1) Instrument Landing System (ILS) ? Displays course and localizer deviation. 2) VHF Omnidirectional Range(VOR) ? Points to the selected VOR course. 3) Navigation(NAV) ? Shows all the necessary information in rose mode. 4) ARC ? Limited to forward 90 degrees sector. 5) PLAN ? Specific to the route visualization. Only the programmed route isdisplayed with all the waypoints in flight plan.
6. EICAS/ECAM The Engine Indications and Crew Alerting System displays information about theaircraft’s systems, such as its fuel, electrical and engines. EICAS displays aredesigned to mimic traditional round gauges while supplying digital readouts of theparameters. It improves the situational awareness by allowing the aircrew to viewcomplex information in a graphical format and alerts aircrews to hazardoussituations. Proper care must be taken when designing EICAS to ensure that theaircrew are always provided with the most important information. 7. WarningandCautionlight The Warning alerts are always displayed in red, and also flashes to capture theattention of the flight crew together with an aural alert. If the attitude or airspeeddisplay fail, the EFIS loses the system valid signal to the display and scalemarkings will be removed as well as the displaying of the associated warning flags.
Cautionary and warning alerts may flash for few seconds before becoming steady,to draw the flight crews’ attention. Location and Placement Control PanelWarning and Caution LightEFIS display units References En.wikipedia.org.(2018).Electronicflightinstrumentsystem.onlineAvailableat:https://en.
wikipedia.org/wiki/Electronic_flight_instrument_system Accessed 15Jan. 2018. Skybrary.aero.
(2018).ElectronicFlightInstrumentSystem-SKYbraryAviationSafety. online Available at:https://www.
skybrary.aero/index.php/Electronic_Flight_Instrument_SystemAccessed 15 Jan. 2018.