AD FAA-2021-0312

The FAA proposes to adopt a new airworthiness directive (AD) for certain De Havilland Aircraft of Canada Limited Model DHC-8-102, - 103, and -106 airplanes; Model DHC-8-201 and -202 airplanes; Model DHC- 8-301, -311, and -315 airplanes; and Model DHC-8-400, -401, and -402 airplanes. This proposed AD was prompted by reports that mounting nuts attaching the rudder actuator bracket to the vertical stabilizer have been found cracked or missing due to hydrogen embrittlement. This proposed AD would require a one-time inspection of the rudder actuator bracket mounting nuts, and corrective actions if necessary. The FAA is proposing this AD to address the unsafe condition on these products.