SAIB ACE-99-01 —

No. ACE-99-01 October 21, 1998

Published by: FAA, AFS-610, P.O. Box 26460, Oklahoma City, OK 73125 This is issued for informational purposes only and any recommendation for corrective action is not mandatory.

Introduction: The purpose of this Special Airworthiness Information Bulletin (SAIB) is to alert owners/operators of all High Wing Piper Airplanes of possible corrosion problems with the strut attach fittings internal to the wing. The following is a list of model numbers for these aircraft: J-2, J-3, J3 series, J4 series, J5 series, PA-11 series, PA-12 series, PA-14, PA-15, PA-16 series, PA-17, PA-18 series, PA-20 series, and PA-22 series. This information is advisory in nature and not mandated by regulation.

Background: This SAIB is a result of an aircraft accident involving a Piper PA-18-150 Super Cub. The aircraft experienced a structural failure of the left wing strut attachment. Post accident examination revealed the cause of the failure to be corrosion of the forward lift strut attach fitting, part number 14192-000. This fitting attaches the outboard end of the lift strut to the wing spar and is composed of forward and aft halves.

Inspection of the forward half of the fitting is not possible without removing the wing leading edge covering. The inspectable part of this fitting is limited to the aft half through an access hole in the lower surface of the wing and the lower portion of both halves where they protrude from the wing. The accident aircraft had not been recovered since 1967 (the fabric still punched good) and the forward half of the fitting had not been inspected since at least that time. Pictures of the failed fitting do show however, that there was evidence of corrosion in the aft and lower areas of the fitting, indicating the likelihood of corrosion to the forward half as well.

Recommendation: Note: Based on currently available information, the FAA is only recommending the following actions. The FAA will continue this investigation and analyze any added information. Additional actions, such as the issuance of an Airworthiness Directive, may be required based on this analysis.

After reviewing the data surrounding this accident the FAA is recommending that owners/operators of the affected aircraft perform immediate inspections of the aft and lower portions of the subject fittings. Part numbers of the fittings are as follows; 11755-2 and 11755-3 for the PA-20 and PA-22 and 14192-000 for all other models. If any evidence of corrosion is detected, the forward portion of the subject fitting should also be inspected. The extent of the corrosion damage should be evaluated by an appropriately licensed mechanic and the parts repaired or replaced accordingly. These areas should then be inspected on a recurring basis during annual and/or 100 hour inspections.

For Further Information Contact: William O. Herderich, Aerospace Engineer, Atlanta Aircraft Certification Office, FAA-Small Aircraft Directorate, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349; Telephone (770) 703-6084; Facsimile (770) 703-6097; email: [email protected].