Aviation Alert
Extracted From:
AC No. 43-16A
Alert No. 313
August 2004

Cessna; Model 340; Wing Attach Fitting; ATA 5741

The operator found two aircraft with intergranular corrosion on the wing attach fittings. One of the aircraft needed both wing forward fittings replaced. The second aircraft needed the left fitting replaced. Part of the wing root fairing can be removed. The wing root panel that covers the fittings is riveted on; therefore, the panel needs to be lifted/pried up a little to get a good look during inspection. The intergranular corrosion actually lifted a chunk of metal from the fitting.

The submitter stated that it appears water is getting trapped in the recess on top of the fittings. This area deserves special emphasis during inspections.

A search of the FAA Service Difficulty Reporting Program data base revealed two additional occurrences identified with a difficulty date of May 1, 1994, and May 5, 1998.

Aircraft total time: approximately 5,500 hours.