AD 2004-05-21 69 FR 11299

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Bombardier airplanes as listed above. This action requires lubrication of the flap actuators, repetitive measurements ("checks") of the backlash of the flap actuators, determination of the next backlash measurement interval, and replacement of discrepant actuators with new or overhauled actuators if necessary. This action is necessary to prevent the mechanical disconnection of a flap actuator, which, if followed by failure of the flap panel's second actuator due to increased loading, could result in flap asymmetry and consequent loss of controllability of the airplane. This action is intended to address the identified unsafe condition.