Automatic Flight and instruments

Question 1

What are the components of the AHRS

Answer 1

Dual attitude and heading reference units
Dual AHRS controllers
Dual Flux valves

Question 2

What are the normal and reduced AHRS modes

Answer 2

Normal for attitude (TAS compensates for acceleration errors in the vertical gyro) and Slaved for heading (Flux valve used to establish the magnetic heading reference)

Reduced modes are Basic for attitude (loss of TAS data subject to drift and acceleration errors (VG/ERECT function used to correct the errors)
And Slaved DG mode, loss of Flux valve. Subject to drift and turn errors

Question 3

Following the application of power, how long does the AHRS take to initialize? What is important in this time?
How do you reset power to the AHRS

Answer 3

3 minutes
Aircraft should remain stationary during initialization
Main and auxiliary DC power recycled. Book says to use CBs but an engineer should do this.

Question 4

How many of the ED-800 displays da each symbol generator capable of displaying?

Answer 4

All 4. If a symbol generator fails, red the reversion mode IAW the checklist. The working symbol generator will display information on all screens

Question 5

What are some of the EADI amber caution and failure annunciators?

Answer 5

FD FAIL flight director failure
ATT2 both using the number 2 attitude source
SG2 using Symbol generator 2 for display
HDG, ATT, ILS are comparator cautions when the input data for the same type of data exceed certain parameters

Question 6

What do the AP, YD, HSI and NAV SEL buttons on the AFCS select?

Answer 6

AP and YD select which autopilot and yaw damper channels are selected. Also connects and disconnects the AP and FD
HSI selects which air data computer, navigation source (lateral and vertical navigation) for flight guidance computers are being used.
NAV SEL allows the active side to switch between nav sources i.e ground based to aux