Flight Instruments

200 210 220 230 240 250 260 270 58 140 120 70 U Y 1 1 0 00 2 10 10 6710 30.30 00:03:29 65 U 80 X V S 60 10 2320B 10 W S 40 70 N E MA239 5800’ IFR APPR ANG 239 A 239 2.3NM Figure 8-15. 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. 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. EFDs also show trend vectors, which show the pilot how the altitude and airspeed are progressing. Trend Vectors 150 Trend vectors are magenta lines that move up and down both the ASI and the altimeter. [Figures 8-16 and 8-17] 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 Figure 8-14. Chelton’s FlightLogic (top) and Avidyne’s Entegra to better control the aircraft’s attitude. By including the trend (bottom) are examples of panel displays that are configurable.140 vectors in the instrument scan, pilots are able to precisely control airspeed and altitude. Additional information can be obtained Air Data Computer (ADC) by referencing the Instrument Flying Handbook or specific EFDs utilize the same type of instrument inputs as traditional avionics manufacturer’s training material. analogue gauges; however, the processing system is different. 130 The pitot static inputs are received by an ADC. The ADC Airspeed trend vector computes the difference between the total pressure and the 1 static pressure and generates the information necessary to 150 display the airspeed on the PFD. Outside air temperatures are also monitored and introduced into various compo1nent2s 0 140 within the system, as well as being displayed on the PFD screen. [Figure 8-15] 130 1 9 120 The ADC is a separate solid state device that, in addition to 9 providing data to the PFD, is capable of providing data to the autopilot control system. In the event of system malfunction, 1the 10 110 ADC can quickly be removed and replaced in order to decrease 100 downtime and decrease maintenance turn-around times. 90 Altitude information is derived from the static pressure port TAS 120KT just as an analogue system does; however, the static press1ure 00 Figure 8-16. Airspeed trend vector. 8-14 90