Service difficulty report · Attach Fitting · Boeing 747422

Difficulty date
July 31, 2004
Submitted
August 10, 2004
Operation
Air carrier
Aircraft
N187UA
Make and model
Boeing 747422
Aircraft serial
26876
Aircraft time
45,724 hours, 5,556 cycles
Engine
Pwa PW4056
System (JASC)
5751 · Ailerons
Part
Attach Fitting
Condition
Cracked
Location
Wing To Aileron
Stage of operation
IN
How discovered
9
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

FOUND APPROX 7.5 INCH VERTICAL CRACK ON THE 2ND FROM OUTBOARD FWD WING TO AILERON HINGE ATTACH FITTING SUPPORT STRUCTURE FOR RIGHT. THE NR 2 RIGHT OUTBOARD AILERON HINGE FITTING HAD BEEN REPLACED DUE TO PRIOR CRACKING. DURING REPLACEMENT A SLIGHT MIS-ALIGNMENT OF THE FITTING WITH THE AILERON INDUCED A SIDE PRELOAD. THIS SIDELOAD CAUSED A CRACK IN THE REPLACED FITTING.