FAA seeks information on Piper wing spar corrosion

The agency is requesting information from aircraft operators on the maintenance history and inspection findings related to the airworthiness concern. AOPA requests that members who wish to submit technical and/or economic impact comments contact AOPA so the comments can be compiled and submitted formally to the FAA.

The airworthiness concern sheet was based on a report from a foreign operator of corrosion on the wing main spar lower cap at the wing station 36 rib that was found during maintenance. According to the notice, Piper Aircraft issued Service Bulletin 1244B to inspect the wing aft spar for corrosion. For the inspection, some aircraft required installation of an access panel.

“During installation of the access panel on a Piper Model PA-28-140, exfoliation corrosion was found on the wing main spar lower cap aft flange upper surface at the WS 36 rib,” the airworthiness concern sheet says, illustrating the problem with a photo.

The Piper airplane models listed in the airworthiness concern sheet use the same spar assembly. Some serial numbers were not manufactured with the access panel as installed per Service Bulletin 1244B.

“Without the access panel, corrosion, cracks or other damage may not be detected on the forward side of the aft spar or on the aft side of the main spar. If undetected or uncorrected, corrosion, cracks or other damage could lead to failure of the lower spar and result in loss of control of the airplane,” the  airworthiness concern sheet says.

Piper proposes to issue a new service bulletin calling for installation of the access panel and performing an initial visual inspection on the main spar for corrosion, cracks, or other damage—similar to Piper Service Bulletin 1244B, which can be reviewed at the Piper Aircraft website.

Members who wish to submit information to AOPA should in particular provide “information and supporting data on maintenance history, inspection findings on the area of concern, estimated costs of the access panel installation and inspection, and any other comments that you feel are necessary. Please be specific and detailed,” the FAA said.