در ویکی پدیا در مورد EFIS  چنین می خوانیم :

An electronic flight instrument system (EFIS) is a flight deck instrument display system that displays flight data electronically rather than electromechanically.


An electronic flight instrument system (EFIS) is a flight deck instrument display system that displays flight data electronically rather than electromechanically. 


An EFIS normally consists of a

primary flight display (PFD), 

multi-function display (MFD), and

an engine indicating and crew alerting system (EICAS) display. 


Early EFIS models used cathode ray tube (CRT) displays, but liquid crystal displays (LCD) are now more common.


 The complex electromechanical attitude director indicator (ADI) and horizontal situation indicator (HSI) were the first candidates for replacement by EFIS.


 Now, however, few flight deck instruments cannot be replaced by an electronic display.

Primary flight display (PFD)[edit]

On the flight deck, the display units are the most obvious parts of an EFIS system, and are the features that lead to the term glass cockpit. 

نمایان ترین بخش سیستم EFIS مربوط به مانیور  PFD می باشد.


The display unit that replaces the ADI is called the primary flight display (PFD).

این سیستم جایگزین سیستم ADI  می باشد.


 If a separate display replaces the HSI, it is called the navigation display.


آنچه که PFD نمایش می دهد عبارت است از :

 The PFD displays all information critical to flight, including

calibrated airspeed,

 altitude,

 heading,

 attitude, 

vertical speed 

and yaw. 


The PFD is designed to improve a pilot's situational awareness by integrating this information into a single display instead of six different analog instruments, reducing the amount of time necessary to monitor the instruments. 

مزیت و یا فلسفه وجودی PFD این است که به جای وجود 6 عدد نمایش گر ، تنها یک نمایشگر وجود داشته باشد تا خلبان با یک نگاه بتواند به راحتی همه موارد را در نظر داشته باشد.



PFDs also increase situational awareness by alerting the aircrew to unusual or potentially hazardous conditions —


 for example, low airspeed, high rate of descent — by changing the color or shape of the display or by providing audio alerts.



The names Electronic Attitude Director Indicator and Electronic Horizontal Situation Indicator are used by some manufacturers.[1]


However, a simulated ADI is only the centerpiece of the PFD. 

centerpiece  : مرکزی


Additional information is both superimposed on and arranged around this graphic.

Multi-function displays can render a separate navigation display unnecessary.

 Another option is to use one large screen to show both the PFD and navigation display.


The PFD and navigation display (and multi-function display, where fitted) are often physically identical.


 The information displayed is determined by the system interfaces where the display units are fitted.


Thus, spares holding is simplified: the one display unit can be fitted in any position.


LCD units generate less heat than CRTs;


 an advantage in a congested instrument panel.


 They are also lighter, and occupy a lower volume.


Multi-function display (MFD)[edit]

The Navigation Display (ND) of a Boeing 737NG Aircraft.

The MFD (multi-function display) displays navigational and weather information from multiple systems.


 MFDs are most frequently designed as "chart-centric", where the aircrew can overlay different information over a map or chart.






Examples of MFD overlay information include 

the aircraft's current route plan,

 weather information from

 either on-board radar or lightning detection sensors or

 ground-based sensors, 

e.g., NEXRAD, 

.restricted airspace and

 aircraft traffic. 



The MFD can also be used to view other non-overlay type of data

(e.g., current route plan) and calculated overlay-type data, e.g., the glide radius of the aircraft, given current location over terrain, winds, and aircraft speed and altitude.


MFDs can also display information about aircraft systems, such as

 fuel and electrical systems (see EICAS, below). 


As with the PFD, the MFD can change the color or shape of the data to alert the aircrew to hazardous situations..


Engine indications and crew alerting system (EICAS) 

/ electronic centralized aircraft monitoring (ECAM)[edit]







EICAS (Engine Indications and Crew Alerting System)

 displays information about the aircraft's systems, including its

 fuel, 

electrical and

 propulsion systems (engines).


 EICAS displays are often designed to mimic traditional round gauges while also supplying digital readouts of the parameters.


EICAS improves situational awareness by allowing the aircrew to view complex information in a 

graphical format and also by

alerting the crew to unusual or hazardous situations. 


For example, if an engine begins to

 lose oil pressure, the EICAS might sound an alert, switch the display to the page with the oil system information and outline the low oil pressure data with a red box.


 Unlike traditional round gauges, many levels of warnings and alarms can be set. 


Proper care must be taken when designing EICAS to ensure that the aircrew are always provided with the most important information and not overloaded with warnings or alarms.


ECAM is a similar system used by Airbus, which in addition to providing EICAS functions also recommend remedial action.


EFIS provides pilots with controls that select display range and mode (for example, map or compass rose) and enter data (such as selected heading).



Where other equipment uses pilot inputs, data buses broadcast the pilot's selections so that the pilot need only enter the selection once. 


For example,

 the pilot selects the desired level-off altitude on a control unit.


The EFIS repeats this selected altitude on the PFD,


 and by comparing it with the actual altitude (from the air data computer) generates an altitude error display.


 This same altitude selection is used by the automatic flight control system to level off, and by the altitude alerting system to provide appropriate warnings.


The EFIS visual display is produced by the symbol generator.


This receives data inputs from the

 pilot, 

signals from sensors, and 

EFIS format selections made by the pilot. 



The symbol generator can go by other names, such as display processing computer, display electronics unit, etc.


The symbol generator does more than generate symbols.


 It has (at the least) 

monitoring facilities,

 a graphics generator and a 

display driver.[2]



Inputs from sensors and controls arrive via data buses, and are checked for validity. 


The required computations are performed, and the graphics generator and display driver produce the inputs to the display units.


Like personal computers, flight instrument systems need power-on-self-test facilities and continuous self-monitoring. 


Flight instrument systems, however, need additional monitoring capabilities:

  • Input validation — verify that each sensor is providing valid data
  • Data comparison — cross check inputs from duplicated sensors
  • Display monitoring — detect failures within the instrument system