HSI/ FDI/ EFDS Flashcards
Function of the FDSDC?
Generates a damped UHF-DF or OTPI bearing signal for display on HSI
What is the function of the FDSC?
Generates ILS glideslope and localizer information for display
Provides fly-to-point steering from computer
What is bearing pointer 1 on all 3 HSI’s?
Pilot bearing
What is bearing pointer 2 on all HSI’s?
Flight station: copilot bearing
NAV/COMM: NAV/COMM bearing
What is the purpose of the NAV/COMM heading marker?
Shows any mismatch angle between the INS heading outputs
Where is the HSI test panel?
On the Forward NAV-J box.
Good indications of pilot HSI test.
- NAV flag is masked from view
- Heading Dial and Course Arrow indicate 180*
- To-from arrow points same direction as Course Arrow
- Distance counter displays 555 on all HSI’s
- Bearing pointer 1 points to top of all HSI’s
- Bearing pointer 2 doesn’t move
- FDI sphere indicates 30* pitch down and 30* left roll
- Gyro flag comes into view.
Good indications of copilot HSI test.
Same as pilot test except:
- Distance counter does not indicate
- Bearing pointer 2 on pilot and copilot HSI’s points to top
- Bearing pointer 1 does not move
Good indications of NAV/COMM HSI test.
Same as pilot except:
- Distance counter does not indicate
- Bearing pointer 1 doesn’t move
- Bearing pointer 2 points to top of HSI
- Heading bug points to top of HSI
Function of vert gyro.
Provides a backup attitude reference for FDIs and FDSC.
Location and function of the ARA-50 amplifier.
- Rack F1
- Amplifies signal from UHF-DF/OTPI antenna and sends to receiver
Where is the OTPI receiver?
Receiver 20 of ASCL receivers.
Function of the ECAs.
Receive synchro information and amplifies it to sufficient power to be displayed.
Function of the NAV-J box.
- Routes NAV, attitude, and status signals
- Switching of NAVAID, heading, and attitude as selected
- 26 Vac synchro excitation voltage for equipment that generates analog signals
How do you initiate diagnostic mode for the MFDs?
Press the PUSH TEST for 2 seconds and within 5 seconds:
- Press HDG knob for 2 seconds for EFDI
- Press BRG knob for 2 seconds for EHSI