SDR 2005UALA01076

Service difficulty report · Transformer · Boeing 737322

Difficulty date: October 2, 2005
Submitted: October 11, 2005
Operation: Air carrier
Aircraft: N378UA
Make and model: Boeing 737322
Aircraft serial: 24653
Aircraft time: 45,078 hours, 31,150 cycles
Engine: Ge CFM56*
System (JASC): 2430 · DC Generating System
Part: Transformer
Condition: Overheated
Location: Nr 1
Stage of operation: IN
How discovered: O
Nature of condition: O
Precautionary procedure: K

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

What was found

NR 1 TRANSFORMER, RECTIFIER WAS FOUND TO HAVE OVERHEAT DAMAGE. FOUND GRND PWR CB-S BURNT. COVER OVER ALL THREE TRANSFORMER-RECTIFIER UNITS WAS BURNED, DUE TO SUSPECTED OVERHEAT IN ONE OR MORE TRS. ALL THREE TRS REPLACED, AS WAS THE BATTERY, BATTERY CHARGER, TR1 CIRCUIT BREAKER C806, AND GROUND SERVICE CIRCUIT BREAKER C813. ALL UNITS REPLACED PRECAUTIONARY. AS OF 10/25 NO SHOP FINDINGS AVAILABLE FOR ANY OF THE REMOVED UNITS.