FAA-2010-0564
This AD is effective September 10, 2013.
Adoption of procedures based on Notice of Proposed Rulemaking (NPRM) on July 8, 2010 wherein helicopters with certain blade grips installed require creating a component history card or equivalent record for each grip; determining and recording the total hours TIS for each grip; visually inspecting the upper and lower tangs of the grip for a crack; inspecting the grip buffer pads for delamination and if delamination is present, inspecting the grip surface for corrosion or other damage; inspecting the grip for a crack using UT and fluorescent penetrant inspection methods; and establishing a retirement life for certain grips.
The NPRM was prompted by reports of three in-flight failures of grips, P/N 204-011-121-009 and 204-011-121-121, installed on Bell Model 212 helicopters. The failures resulted from cracks originating in the lower blade bolt lug. The cracking was attributed to subsurface fatigue, corrosion and mechanical damage. Grips with these same P/Ns are eligible for installation on certain restricted category helicopters. Grips, P/N 204-3 044-121-005 and 204-044-121-113, are also affected if they were ever installed on a Model 205B or UH-1N helicopter. The proposed requirements were intended to prevent failure of the grip, separation of a main rotor blade, and subsequent loss of control of the helicopter.
http://www.rotor.com/rotornews/Aug13/2013-13-06.pdf