We propose to supersede an existing airworthiness directive (AD) that applies to all The Boeing Company Model 777-200, -200LR, - 300, and -300ER series airplanes. The existing AD currently requires repetitive inspections for cracking of the elevator actuator fittings. Since we issued that AD, the manufacturer has developed a modification that was approved as an optional terminating action to the currently required repetitive inspections. We have been advised that the modification procedures include certain incorrect torque values. This proposed AD would require, for previously modified airplanes, repetitive inspections for movement of the fittings or fastener heads, and eventual replacement of certain bolts (including related investigative and corrective actions if necessary). For all airplanes, this replacement, with corrected torque values, would terminate the requirements of the AD. This proposed AD would also remove certain airplanes from the applicability. We are proposing this AD to detect and correct a cracked actuator fitting or incorrectly installed bolts to the actuator fitting, which could lead to the elevator becoming detached and unrestrained, and a consequent unacceptable flutter condition and loss of control of the airplane.
Agency Contact: Melanie Violette, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, WA 985057-3356; phone: 425-917-6422; fax: 425-917-6590; email: firstname.lastname@example.org.
This is a proposed regulation. Comments were due on September 17, 2012.