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Pilot's Handbook of Aeronautical Knowledge
Flight Instruments
Electronic Flight Display (EFD)

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Pilot's Handbook of Aeronautical Knowledge

Preface

Acknowledgements

Table of Contents

Chapter 1, Introduction To Flying
Chapter 2, Aircraft Structure
Chapter 3, Principles of Flight
Chapter 4, Aerodynamics of Flight
Chapter 5, Flight Controls
Chapter 6, Aircraft Systems
Chapter 7, Flight Instruments
Chapter 8, Flight Manuals and Other Documents
Chapter 9, Weight and Balance
Chapter 10, Aircraft Performance
Chapter 11, Weather Theory
Chapter 12, Aviation Weather Services
Chapter 13, Airport Operation
Chapter 14, Airspace
Chapter 15, Navigation
Chapter 16, Aeromedical Factors
Chapter 17, Aeronautical Decision Making

Appendix

Glossary

Index

Chelton’s FlightLogic (top) and Avidyne’s Entegra (bottom) are examples of panel displays that are configurable.
Figure 7-14. Chelton's FlightLogic (top) and Avidyne's Entegra
(bottom) are examples of panel displays that are configurable.

Air Data Computer (ADC)
Electronic flight displays utilize the same type of instrument
inputs as traditional analogue gauges; however, the processing
system is different. The pitot static inputs are received by an
ADC. The ADC computes the difference between the total
pressure and the static pressure, and generates the information
necessary to display the airspeed on the PFD. Outside air
temperatures are also monitored and introduced into various
components within the system, as well as being displayed on
the PFD screen. [Figure 7-15]

The ADC is a separate solid state device which, in addition to
providing data to the PFD, is capable of providing data to the
autopilot control system. In the event of system malfunction,
the ADC can quickly be removed and replaced in order to
decrease down time and maintenance turn-around times.

Altitude information is derived from the static pressure port
just as an analogue system does; however, the static pressure
does not enter a diaphragm. The ADC computes the received
barometric pressure and sends a digital signal to the PFD to
display the proper altitude readout. Electronic flight displays
also show trend vectors which show the pilot how the altitude
and airspeed are progressing.

Teledyne’s 90004 TAS/Plus Air Data Computer (ADC)
Figure 7-15. Teledyne's 90004 TAS/Plus Air Data Computer (ADC)
computes air data information from the pitot-static pneumatic
system, aircraft temperature probe, and barometric correction
device to help create a clear picture of flight characteristics.

Trend Vectors
Trend vectors are magenta lines which move up and down
both the ASI and the altimeter. [Figures 7-16 and 7-17] The
ADC computes the rate of change and displays the 6-second
projection of where the aircraft will be. Pilots can utilize
the trend vectors to better control the aircraft's attitude. By
including the trend vectors in the instrument scan, pilots are
able to precisely control airspeed and altitude. Additional
information can be obtained by referencing the Instrument
Flying Handbook or specific avionics manufacturer's training
material.

Airspeed trend vector.
Figure 7-16. Airspeed trend vector.

ADC computes the rate of change and displays the 6-second
projection of where the aircraft will be. Pilots can utilize
the trend vectors to better control the aircraft's attitude. By
including the trend vectors in the instrument scan, pilots are
able to precisely control airspeed and altitude. Additional
information can be obtained by referencing the Instrument
Flying Handbook or specific avionics manufacturer's training
material.

 

7-14