Summary
We propose to adopt a new airworthiness directive (AD) for the products listed above that would supersede an existing AD. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:
Several reports have been received about roll control problems due to frozen moisture on the aileron pulleys that are located in the LH [left-hand] and RH [right-hand] Main Landing Gear (MLG) wheel bays on the centre wing rear spar, under the wing to fuselage fairings. Investigation revealed that improper sealing of the aerodynamic seals of the Wing-to-Fuselage Fairings can cause rain-or washwater and de-icing fluids to leak onto the affected aileron pulleys. Exposure of the aileron pulleys to the leaked moisture in freezing condition can result in restricted aileron control movement (partly jammed) and/orhigher control forces. This condition, if not corrected, could lead to partial loss of control of the aircraft. * * *
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The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.