# SDR CALA0700030

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 23, 2007
- Submitted: January 24, 2007
- Operation: Air carrier
- Aircraft: [N77006](https://openairdocs.org/aircraft/N77006), registered now
- Make and model: Boeing 777224
- Aircraft serial: 29476
- Aircraft time: 38,968 hours, 4,472 cycles
- System (JASC): [2897 · Fuel System Wiring](https://openairdocs.org/jasc/2897)
- Part: Connector
- Part number: 280W00021
- Condition: Burned
- Location: Nr 1 Boost Pump
- Stage of operation: IN
- How discovered: O
- Nature of condition: M
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA0700030

## Discrepancy

NR 1 MAIN FUEL TANK FORWARD BOOST PUMP FOUND INOPERATIVE.  PUMP WAS PLACARD INOPERATIVE.  MX FOUND PUMP TO BE EXTREMELY HOT DURING TROUBLESHOOTING.  CONNECTOR COULD NOT BE REMOVED & WIRING HAD MELTED OFF PUMP.  APPROX 6 INCHES OF WIRING HARNESS WAS BURNED & CONNECTOR WAS BURNED.  RELATED CIRCUIT BREAKER HAD NOT POPPED.  BOOST PUMP CONNECTOR PINS BURNED. ARCING OF PINS HAS BEEN ADDRESSED IN BOEING SERVICE BULLETIN 777-28-0028. VENDOR TEARDOWN FOUND THAT THE PRIMARY CAUSE OF THE PIN FAILURE TO BE CONTAMINANT INGRESS/PRESENCE. CONTAMINANT COMBINED WITH FRETTING DAMAGE TO GOLD LAYER OF PINS RESULTS IN GALVANIC CORROSION DAMAGE BETWEEN THE PINS AND AIRCRAFT FEMALE SOCKETS.

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