Original Issue November 1, 2019
Revision 1 November 19, 2019
(Note: This SEL is provided for information. Please refer to AD 2020-03-16)
The carry-thru spar can develop corrosion and cracks. Corrosion can propagate and lead to crack development. A crack in the carry-thru spar can progress to a point that a structural failure of the carry-thru spar can occur, resulting in loss of airplane control and/or wing separation.
Non-compliance with this service letter may result in undetected corrosion and crack(s) in the carry-thru spar, which can result in structural failure of the carry-thru spar.
This service document provides instructions and repair criteria to do a detailed inspection of the carry-thru spar to inspect for corrosion and/or cracks.
See attached PDF.