SDR CALA2025081907940

Service difficulty report · Control Unit · Boeing 7879

Difficulty date: August 18, 2025
Submitted: August 19, 2025
Operation: Air carrier
Aircraft: N28987
Make and model: Boeing 7879
Aircraft serial: 66146
Aircraft time: 21,941 hours, 2,119 cycles
System (JASC): 3350 · Emergency Lighting
Part: Control Unit
Condition: Faulted
Location: Zone 200
Stage of operation: IN
How discovered: C
Nature of condition: L
Precautionary procedure: K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

DURING OPS CHK FOR EMERGENCY LIGHT, FOUND NO FLOOR PROXIMITY LIGHTS COME ON SEAT 11D, 12D, 11F, 12F. REMOVED AND REPLACED WELS CONTROL UNIT (WCU 24) IAW AMM A-33-51-07-01A-720A-A. REQUIRES SOFTWARE INSTALLATION STEP 1.D. INSTALLED SOFTWARE ON WELS CONTROL UNIT REF AMM 33-51-07-01A-720A-A STEP 1 D. OPS CHECKED GOOD.

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