The FAA has issued a special airworthiness information bulletin (SAIB) warning the owners of Beechcraft Debonairs, Bonanzas, and Barons about the potential for corrosion on the wing leading edge hinge pin. According to the FAA, the problem appears to be caused by an accumulation of deicing fluid in the area of the pin.
The Sept. 15 SAIB recommends inspection of the front spar leading edge lower hinge pin area for corrosion while the under wing access panels are off during the annual inspection. If corrosion is found, owners are advised to contact Beechcraft Customer Support for instructions.
Corrosion issues have been found on a dozen aircraft so far, including two Bonanza G36s. Affected models include 35-33; 35-A33; 35-B33; 35-C33; 35-C33A; E33; E33A; F33; F33A; G33; 36; A36; G36; A36TC; B36TC; S35; V35; and V35B, B55, C55, D55, E55, and 58 airplanes.
While all of the corrosion issues found so far have involved aircraft with deicing equipment, the American Bonanza Society has followed the issue closely and is urging its members to inspect wing leading edge hinge pins at each annual inspection, regardless of whether the aircraft is equipped for deicing.