Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Bombardier Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 airplanes. This proposal would require a one-time inspection to determine the serial numbers of the elevator and aileron servos of the drive assemblies of the automatic flight control system, and follow-on corrective actions if necessary. This action is necessary to prevent separation of the screws from the autopilot clutch assembly of the SM-300 servo, which could result in uncommanded engagement of the autopilot servo and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.