Leveling and Tilting the Light Head (LHA)

Prerequisites / Safety Notes

• Work only when authorized and with proper lockout/tagout procedures if required.
• Handle the Photosensor harness on the Primary unit with extreme care to avoid stress or damage.
• Use appropriate PPE (gloves, eye protection) when working around energized equipment.

Step-by-Step Instructions

1. Remove the Top Cover
   • Carefully remove the top cover of the LHA.
   • Caution: On the Primary unit, avoid stressing or pulling on the photosensor harness.
2. Set Dip Switches to Test Mode 1
   • Configure dip switches as follows:
     • SW1-6: ON
     • SW1-8: ON
     • SW2-8: OFF
   • This mode allows the system to operate while ignoring Tilt or Communication failures.
3. Loosen Mounting Hardware
   • Remove the top flange nuts on each mounting leg (front and rear legs).
   • Leave the lower flange nuts in place for initial adjustments.
4. Energize the System
   • Use the circuit breaker in the PDU
5. Perform Horizontal Leveling
   • Press the LEVEL button on the control/display panel to initiate horizontal leveling.
   • Using the lower flange nuts on the two front legs, adjust the LHA until the display reads 0.00 (perfect level).
6. Set Glide Slope Tilt/Angle
   • Press the GLIDE button.
   • Using the lower flange nut on the rear leg, adjust the tilt/angle of the LHA until the display shows the desired angle in Decimal Degrees
7. Secure and Fine-Tune
   • Reinstall and hand-tighten the upper flange nuts on all legs.
   • Make minor adjustments as needed to maintain the display reading of 0.00 (level) or the exact desired glide slope angle.
   • Fully tighten all upper flange nuts once satisfied.
8. Save the Configuration
   • Press SET repeatedly until the display reads SAVE.
   • The LHA is now calibrated to detect deviations from the desired glide slope.
9. Return to Normal Operation Mode
   • Reset all dip switches to Normal mode:
     • SW1 positions 6, 7, and 8: OFF
     • SW2: All OFF
     • SW1 positions 1–5: Set to normal field settings (as per site configuration).
   • The system will now resume full operational functionality, including tilt and communication monitoring.
10. Final Steps
    • Replace and securely fasten the top cover.
    • Verify system status on the display/control panel.
    • Perform a functional check or log the calibration if required by maintenance procedures.

Additional Notes

• Always confirm the desired glide slope angle matches airport specifications
• If system does not function as it should recheck dip switch settings.
• Document all adjustments, including before/after readings and any deviations noted.

 

Airport Lighting Company | L-880(L), L-881(L) Precision Approach Path Indicator Lights (PAPI)