Action
Final rule.
Summary
We are superseding Airworthiness Directive (AD) 2009-05-09 for Bell Model 412, 412CF, and 412EP helicopters. AD 2009-05-09 required reidentifying each affected part-numbered main rotor yoke (yoke) on its data plate, reducing the retirement life of the reidentified yoke, and revising the Airworthiness Limitations section of the maintenance manual or the Instructions for Continued Airworthiness (ICAs) accordingly. This new AD retains the requirements of AD 2009-05-09 with the exception of the P/N marking location. This AD was prompted by fatigue analysis that shows the retirement life should be reduced on certain yokes. We are issuing this AD to correct the unsafe condition on these helicopters.