• Runway Flag: Notes:

  The runway flag and symbol are biased out-of-view when a VOR frequency is tuned. Tuning an ILS frequency causes the Runway Flag to bias in-to-view. With a valid localizer signal, the Runway Flag will bias out-of-view, and the runway symbol will come into view. The runway symbol moves left and right to indicate localizer deviation, and starts to rise as the airplane descends below 200 feet radio altitude.

  
  Runway Flag-in-view:

  1.Place the HSI selector switch on the glareshield in the VOR/ILS position and observe the NAV flag on the HSI directly below the ADI with the RUNWAY flag in-view:
  
  2.If the NAV flag is NOT-IN-VIEW on the HSI, then the problem is with the ADI. To further verify do one or both of the following:
  
  2a.Move the VHF Nav XFR switch on the P5 overhead panel to "Capt On Aux" or "F/O On Aux" and observe the Runway flag. If it stays in-view with a different NAV source then its the ADI at fault.
  
  2b.Run the ILS self-test on the VHF nav control panel and observe the indications on both the ADI and HSI. IF the ADI Runway flag is in-view throughout the test but the HSI Nav flag is not then the ADI is bad.
  
  3.If the Runway Flag on the ADI and the NAV Flag on the HSI below are BOTH-IN-VIEW, then you have a source problem. Do the following to verify:
  
  3a.Move the VHF Nav XFR switch on the P5 overhead panel to "Capt On Aux" or "F/O On Aux" and observe the Runway flag on the ADI and Nav flag on the HSI. If both flags pull from view, then the normal source feeding those indicators is at fault. Proceed to trouble shoot the VHF Nav receiver.
  
  ADI INFORMATION:

  

  
  Circuit Breakers:

  ADI #1: P18-2 = B1.

  ADI #1 ALTN: P6-1 = C8.

  ADI #2: P6-1 = B8.

  ADI #2 ALTN: P18-2 = B2.

  Instrument Transformer 2: P6-1 = A12.

  Instrument Transformer 1: P18-2 = A1.

  VHF NAV LOC 1: P18-1 = A1.

  VHF NAV LOC 2: P6-1 = A-15.

  
  Additional Notes:

  On those aircraft that have only 2 VHF Nav receivers, the VHF Nav XFR switch is labeled "Both On 1" or "Both On 2." The results previously described using the XFR switch should be the same.

  
  The vertical movement of the runway symbol is controlled by the on-side Radio Altimeter R/T unit. The RUNWAY flag circuit does not look at the radio altitude signal, only the localizer input and the indicator itself.
  
  Applicable deferrals 34-17=VHF ILS System.

Training Only