57-004 - Pacific Aerospace Cresco 08-600 Aircraft - Excessive Wear found in Wing Rear Spar to Fuselage Attach Fittings

ATA Chapter: 57

Subject:

CAA have received a defect report of a finding of significant damage in the wing rear spar to fuselage attach fittings on a Cresco aircraft caused by movement of the bolts.

Applicability:

All Cresco 08-600 aircraft.

Purpose:

CAA have received a defect report of a finding of significant damage in the wing rear spar to fuselage attach fittings on a Cresco aircraft caused by movement of the bolts. For further detail refer to the photos below.

Background:

The defect report states that the bolt holes in the wing rear spar to fuselage fittings were found to be beyond maximum allowable oversize, which required a modification to correct. It was also found that the bolt heads had created 0.034” and 0.039” indentations in the spar attach fittings. The defect report stated that early detection of spar attachment wear and damage was prevented due to the application of a thick flexible sealant to the bolt heads and fittings.

Recommendation

Maintenance engineers are reminded of the importance of following the appropriate instructions for continuing airworthiness (ICA) when applying sealants and compounds to structural components, and when preparing any area for inspection.