airworthiness · Rule · Final rule. · Published 2012-04-10 · Effective 2012-05-15 · 77 FR 21402
Document
Document number
2012-8052
Federal Register citation
77 FR 21402
Type
Rule
Action
Final rule.
Category
airworthiness
Manufacturer
Sikorsky
Publication date
2012-04-10
Effective date
2012-05-15
FAA docket
Docket No. FAA-2011-1113
Abstract
We are adopting a new airworthiness directive (AD) for Sikorsky Aircraft Corporation (Sikorsky) Model S-92A helicopters. This AD was prompted by the discovery of tail rotor blade assemblies (blades) manufactured with mislocated aluminum wire mesh, leaving portions of the graphite torque tube (spar) region unprotected from a lightning strike. The actions are intended to detect mislocated blade wire mesh and to prevent spar delamination, loss of the blade tip cap during a lightning strike, blade imbalance, loss of a blade, and subsequent loss of control of the helicopter.