Summary
We propose to adopt a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-8-400 series airplanes. This proposed AD was prompted by test reports showing that failure of a retract port flexible hose of a main landing gear (MLG) retraction actuator could cause excessive hydraulic fluid leakage. This proposed AD would require a detailed inspection for defects and damage of the retract port flexible hose on the left and right MLG retraction actuator, and replacement of the flexible hose if needed. We are proposing this AD to detect and correct defects and damage of the retract port flexible hose which could lead to an undamped extension of the MLG and could result in MLG structural failure, leading to an unsafe asymmetric landing configuration.