An electronic flight instrument system (EFIS) is a flight deck instrument display system located at the flight cockpit in the lower deck after the windshield. It is powered electronically and produce digital output. The electronic display unit system consists of 3 different display units, the Primary Flight Display(PFD), Navigational Display(ND) and EICAS / ECAM based on the engine 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 six or more display units.
Typical display of Electronic flight instrument system (EFIS) Purpose of Electronic Flight Instrument System (EFIS)
The purpose of an Electronic Flight Instrument System (EFIS) in an aircraft is to display output flight data in a CRT or LCD screen to monitor the progress of the aircraft’s flight and the correct function of all aircraft’s parts and system. As well as display essential information to aid the flight crew to operate the aircraft in a safe and efficient way. The EFIS units aid the pilot in controlling of the aircraft and making decision during flight to the intended destination, by providing the flight information and navigational information of the flight performance.
Block diagram of Electronic flight instrument system (EFIS) Operations and functions of each unit of EFIS
Air Data Inertial reference unit The inertial reference unit is connected to the aircraft sensors all around the aircraft to produce flight and air data. The sensors include pitot static tube and ring laser gyroscope. The whole system can be split into 2 units, the air data unit and inertial reference unit. In the air data unit, the pitot static tubes are used with air data modules to convert air pressure into electrical signal magnitudes to the Inertial reference unit through data buses. With the calculation of Airspeed, Mach number, temperature and barometric pressure altitude. The Air Data Inertial reference unit then compiles the information and process it to send to the next phase to display the result.
Navigational data Navigational Data is a common block of data that gives navigational information to guide the aircraft to reach the intended destination safely and efficiently through available or decided routes and communication. The data taken from different sensors and instruments around the aircraft. Such as weather radars, transponders, and etc. The navigation data consist of the weather data, instrument landing system data, flight path data, traffic collision alerting system data, and etc. Which aids the aircraft to navigates properly.
EFIS Control Panel EFIS control panel helps to give manual control to the pilot to select the settings and control the displays by choosing what information to be displayed in the CRT or LCD displays. They provide the pilots with the controls to the displays such as brightness, range and mode settings in maps and to show preferred data and to enter data.
Primary Flight display (PFD) A primary flight displays (PFD) is an instrument dedicated to flight information. It is a representation of “steam gauge” instruments, combined on one compact display, to help simplifying the pilot’s workflow and streamlining cockpit layouts. The flexibility in the system makes it possible to display at any given moment only the information required for the present flight phase.
Navigation display (ND) The navigation displays (ND) displays navigational and weather information from multiple systems. It is designed as “chart-centric”, the aircrew can overlay different information over a map or chart. The ND overlay information such as the aircraft’s current route plan, weather information from either on-board radar or lightning detection sensors or ground-based sensors, restricted airspace and aircraft traffic. It can be used to view other non-overlay type of data such as current route plan and calculated overlay-type data such as the glide radius of the aircraft, the given current location over terrain, winds, and aircraft speed and altitude. ND can also display information about aircraft systems, such as fuel and electrical systems and changes the colour or shape of the data to alert the aircrew of hazardous situations.
EICAS/ ECAM The Engine Indications and Crew Alerting System displays information about the aircraft’s systems, such as its fuel, electrical and engines. EICAS displays are designed to mimic traditional round gauges while supplying digital readouts of the parameters. It improves the situational awareness by allowing the aircrew to view complex information in a graphical format and alerts aircrews to hazardous situations. Proper care must be taken when designing EICAS to ensure that the aircrew are always provided with the most important information. Location and Placement