Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to adopt a new airworthiness directive (AD) for certain Agusta Model AB139 and AW139 helicopters. This proposed AD would require performing operational checks of both hydraulic systems. This proposed AD is prompted by an assessment of the hydraulic systems of the helicopter following an accident. The proposed actions are intended to prevent loss of hydraulic power to the flight controls and subsequent loss of control of the helicopter.