Airworthiness Directives; Boeing Model 757 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to all Boeing Model 757 series airplanes. For certain affected airplanes, this action requires repetitive testing of the secondary brakes of the horizontal stabilizer trim actuator (HSTA). For all affected airplanes, this action requires repetitive overhauls of the primary brake and differential assembly of the HSTA, which would constitute terminating action for the repetitive testing of the secondary brake. This action is necessary to prevent grease contamination on the primary HSTA brake and consequent loss of the primary brake function, which, in combination with the loss of the secondary HSTA brake function, could result in loss of control of the airplane. This action is intended to address the identified unsafe condition.
Airworthiness Directives; Bombardier Model DHC-8-400 Series Airplanes
The FAA is adopting a new airworthiness directive (AD) for certain Bombardier Model DHC-8-400 series airplanes. This AD requires inspecting the electrical connectors of the fire extinguisher bottles for the forward and aft baggage compartments and for the auxiliary power unit and engine nacelles to determine if they are connected correctly; and doing related investigative and corrective actions, if necessary. This AD is prompted by reports of the electrical connectors for the fire bottles in the forward and aft baggage compartments being cross connected. We are issuing this AD to detect and correct cross connection of the fire extinguisher bottles, which could result in failure of the fire bottles to discharge and consequent inability to extinguish a fire in the affected areas.