SDR 2003UALA00626

Service difficulty report · Indicator · Boeing 737322

Difficulty date: August 13, 2003
Submitted: August 19, 2003
Operation: Air carrier
Aircraft: N311UA
Make and model: Boeing 737322
Aircraft serial: 23672
Aircraft time: 46,866 hours, 25,266 cycles
Engine: Ge CFM56*
System (JASC): 2751 · Trailing Flap Position Indicating System
Part: Indicator
Condition: Inoperative
Location: Te Flap
Stage of operation: CL
How discovered: O
Nature of condition: O
Precautionary procedure: A

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

What was found

RETURN TO FIELD DUE TO A FLAP POSITION INDICATOR. FLAP SYSTEM MALFUNCTION WAS CAUSED BY INTERNAL FAILURE OF THE FLAP POSITION INDICATOR. THE INDICATOR WAS REPLACED AND THE FLAP SYSTEM WAS TESTED FOR PROPER OPERATION. THE INDICATOR PASSED A BENCH TEXT, HOWEVER AMTS BELIEVED THE BRUSH TENSION WAS TOO HIGH. UPON DISASSEMBLY, THE BEARING AND SHAFT WERE FOUND MISALIGNED. THIS RESULTED IN THE BRUSHES CONTACTING THE SLIP RING AT AN ANGLE APPROXIMATELY 20 DEGREES FROM PERPENDICULAR.