Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to supersede an existing airworthiness directive (AD) for Bell Helicopter Textron (Bell) Model 222, 222B, 222U, 230, and 430 helicopters. The existing AD currently requires inspecting parts of the main rotor hydraulic servo actuator (servo actuator) for certain conditions and replacing any unairworthy parts before further flight. Since we issued the AD, a new stainless steel piston rod has been manufactured. We propose requiring the installation of a servo actuator assembly with this piston rod and setting an interval for the next overhaul at 10,000 hours time-in-service (TIS) or 10 years, whichever comes first. The proposed actions are intended to detect pitting or penetration of the base metal of the piston rod that could lead to the piston rod's failure, the servo actuator's failure, and the loss of helicopter control.