Service difficulty report · Drive Unit · Boeing 747238B

Difficulty date
April 26, 1996
Submitted
March 26, 2000
Operation
Air carrier
Aircraft
N159UA
Make and model
Boeing 747238B
Aircraft serial
21140
Engine
Pwa JT9D7J
Part
Drive Unit
Condition
Failed
Location
Nr 1 Le Flap
Component
Allied Signa · 12624841
Stage of operation
CL
Nature of condition
F, J
Precautionary procedure
A

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

What was found

NR 1 LEADING EDGE FLAP FAILED TO RETRACT. *S/D* DRIVE UNIT FAILED TO RETRACT PNEUMATICALLY OR ALTERNATELY AFTER TAKEOFF. DISASSEMBLY OF THE FAILED UNIT REVEALED A FAILED AIR ROTOR BEARING. ADDITIONALLY THE ALTERNATE DRIVE MOTOR FAILED, PROBABLY DUE TO EXTENDED OPERATION OF THE DRIVE UNIT AFTER THE PNEUMATIC MODE FAILURE.