AVIONICS UNIT 2

Flight deck displays technologies An electronic flight instrument system

(EFIS) is a flight deck instrument display system in which the display technology used is electronic rather than electromechanical.

PFD , MFD, EICAS, CRT, LCD The complex electromechanical attitude

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

EFIS installations vary greatly. A light aircraft might be equipped with one display unit, on which are displayed flight and navigation data. A wide-body aircraft is likely to have six or more display units.

An EFIS installation will follow the sequence:

Displays

Controls

Data processors

DISPLAY

FDDT(A380)

PDF 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 colour or shape of the display or by providing audio alerts.

The PFD displays all information critical to flight, including calibrated airspeed, altitude, heading, attitude, vertical speed and yaw.

Single display instead of six different analogue instruments

Replaces ADI(altitude indicator) LCD,CRT are used

PDF

MFD

Displays navigational and weather information from multiple systems.

MFDs can also display information about aircraft systems, such as fuel and electrical systems . As with the PFD, the MFD can change the colour or shape of the data to alert the aircrew to hazardous situations.

MFD

EICAS Displays information about the aircraft's systems,

including its fuel, electrical and propulsion systems (engines).

EICAS improves situational awareness. 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.

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.

CONTROL PANELS

The pilots are provided with controls, with which they select display range and mode (for example, map or compass rose) and enter data (such as selected heading).

Command clashing. Error correction. Verification of data with onboard

computer. Cross check.

Data processor

Different data obtained by the sensors is checked and verified and displayed on the system.

All the data obtained is accurate and cross verified

The calculation and done in a series of algorithms.

Other parameters Human factors.

(clutter , colour) Clutter- its states the priorities of emergencies, when an

equipment is removed. Colour- states the different states in aircraft attitude. Advancements( highly came in use after 1980 in Boeing

and airbus. Recent advances in computing power and reductions in

the cost of liquid-crystal displays and navigational sensors (such as GPS and attitude and heading reference system) have brought EFIS to general aviation aircraft. Notable examples are the Garmin G1000 and Chelton Flight Systems EFIS-SV.

CRT (cathode ray tube)

1. Three Electron guns (for red, green, and blue phosphor dots)2. Electron beams3. Focusing coils4. Deflection coils5. Anode connection6. Mask for separating beams for red, green, and blue part of displayed image7. Phosphor layer with red, green, and blue zones8. Close-up of the phosphor-coated inner side of the screen

LCD (liquid crystal display)

Polarizing filter film with a vertical axis to polarize light as it enters.

Glass substrate with ITO electrodes. The shapes of these electrodes will determine the shapes that will appear when the LCD is turned ON. Vertical ridges etched on the surface are smooth.

Twisted nematic liquid crystal. Glass substrate with common

electrode film (ITO) with horizontal ridges to line up with the horizontal filter.

Polarizing filter film with a horizontal axis to block/pass light.

Reflective surface to send light back to viewer. (In a backlit LCD, this layer is replaced with a light source.)

TOUCH SCREEN

HUD (head up display)

HMD(helmet mounted display)

Scorpion HMCS IHADSS

JHMCS

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