airworthiness · Rule · Final rule; request for comments. · Published 2013-10-25 · Effective 2013-10-25 · 78 FR 63850
Document
Document number
2013-24937
Federal Register citation
78 FR 63850
Type
Rule
Action
Final rule; request for comments.
Category
airworthiness
Manufacturer
AgustaWestland S.p.A. (Agusta)
Publication date
2013-10-25
Effective date
2013-10-25
FAA docket
Docket No. FAA-2013-0881
Abstract
We are adopting a new airworthiness directive (AD) for Agusta Model A109A, A109A II, A109C, A109E, A109K2, A109S, AW109SP, A119, and AW119 MKII helicopters. The emergency AD was sent previously to all known U.S. owners and operators of these helicopters. This AD requires, before further flight, inspecting certain Thomas coupling nuts on the tail rotor drive shaft line for a crack and replacing all the nuts if any nut is cracked. Also this AD requires replacing all affected Thomas coupling nuts within 10 hours time-in-service (TIS) or 30 days, whichever occurs first. This AD was prompted by two incidents of cracking on the nuts that connect the flexible disc coupling (Thomas coupling) with the splined adapter on the tail rotor drive shaft. We are issuing this AD to correct the unsafe condition on these helicopters.