Action
Supplemental notice of proposed rulemaking (NPRM); reopening of the comment period.
Summary
This supplemental NPRM revises an earlier proposed airworthiness directive (AD), applicable to Dowty Propellers Models R354/4-123-F/13, R354/4-123-F/20, R375/4-123-F/21, R389/4-123-F/25, R389/4-123-F/26, and R390/4-123-F/27 propellers. That proposed AD would have required initial and repetitive visual inspections of propeller blade root outer sleeves for cracks, and removal before further flight of propeller blades with cracked blade root outer sleeves. That proposed AD resulted from mandatory continuing airworthiness information (MCAI) issued by the European Aviation Safety Agency (EASA) to identify and correct an unsafe condition on certain Dowty propellers. This supplemental NPRM revises the proposed AD to correct the listing of propeller models affected. This supplemental NPRM results from the discovery that we need to correct one of the propeller model numbers affected, and to remove an erroneous propeller model number. We are proposing this AD to prevent blade counterweight release, which could result in injury or damage to the airplane. The MCAI describes the unsafe condition as: