Flight Instruments

Question 0

What happens when the ED fails?

Answer 0

Its image is automatically transferred to the #1 MFD, provided that MFD 1 rotary switch is set to NAV or SYS, IAS from ADC 1 less than 50 KIAS or is invalid, and PFD is not selected to MFD 1. The crew can manually display this information on the #2 MFD using the ESCP.

Question 1

Describe the ADUs.

Answer 1

The Air Data Units gather information from the pitot static probes, air temperature probes, index control panels, PSEU, and ADC test switch. This information is used for pressurization, flight guidance and control, navigation, indication, Vmo Warning, and Powerplant Operation.

Question 2

Describe an ADC test.

Answer 2

1. Confirm EFIS ADC SOURCE is NORM, ALT IAS & IVSI FAIL Flags are out on both PFDs, and a valid SAT is displayed on the ED.
2. TEST and observe:
   • Baro Setting 29.23”
   • Baro ALT 14,360
   • Vmo 284
   • KIAS 285 - red
   • Overspeed warning horn after 5 seconds
   • SAT -15°C on ED (only when testing #1 SYS)
   • WTG # FAIL (as appropriate) on ED
   • PITCH TRIM & ELEVATOR FEEL Caution Lights
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