MISC LIGHTS

Question 1

PSEU LIGHT

Answer 1

[1sp - proximity switch problem - no go condition]

• Proximity Switch Electronic Unit Light
• Illuminated (Amber):
  
  • Ground:
    
    • a fault is detected in the PSEU OR
    • overwing exit lock failed to DISENGAGE when commanded
  • In Flight:
    
    • inhibited from THRUST LEVER ADVANCE for TAKEOFF until 30 SECONDS AFTER LANDING
• Does not immediately illuminate for a SINGLE FAULT (on recall only)
• PSEU light extinguishes when a parking brake is set or when both engines are shut down
• light is reset by MAINT via a BITE check or fault repair.
• Monitors: Takeoff Config, Landing Config, Landing Gear, Air/Gnd sensors

Question 2

GPS LIGHT

Answer 2

• Illuminated (Amber): [DUAL CHANNEL LIGHT]
  
  • indicates a SINGLE GPS failure (on recall) - has nothing to do with LOSS of SIGNAL
  • indicates a failure of BOTH GPS SENSORS (if light comes on automatically). GPS light will NOT go out after the MC and Caution Panel reset
• GPS DUAL FAILURE ISSUES:
  
  • position information now comes from radio (DME) and IRS sensor inputs
  • Look ahead terrain alerting and display unavailable due to position uncertainty
  • with GPS inop - expect ANP to grown when using DME/DME updating