Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to adopt a new airworthiness directive (AD) for Bell Model 407 helicopters. This proposed AD would require repetitive inspections of the tail rotor (TR) driveshaft segment assemblies and a torque check of the TR adapter retention nuts. This proposed AD is prompted by a report of an in-flight failure of the TR drive system. The proposed actions are intended to detect and correct an unsafe condition on these products.