Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier Model DHC-8-102, -103, -106, -201, -202, -301, - 311, and -315 airplanes. This proposed AD would require operators to install torque tube catchers on the control columns of the flight controls. This proposed AD is prompted by the discovery that a single malfunction of the torque tube could result in both flight control columns being supported by only one self-aligning bearing. We are proposing this AD to prevent the torque tube from fouling against the underfloor control cables, which could result in reduced controllability of the airplane.