Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 777-200, -200LR, -300, and -300ER series airplanes. This proposed AD was prompted by reports of severe corrosion on bonding jumpers installed on the flight control surfaces. This proposed AD would require repetitive bonding jumper inspections for corrosion, sealant disbond, and insufficient sealant coverage, and corrective actions if necessary. This proposed AD also specifies an optional action of doing an inspection for corrosion damage of the bonding brackets, and corrective actions if necessary, which would terminate the repetitive inspections. For certain airplanes, this proposed AD would also require installing certain bonding jumpers and related ground clips and fasteners to the elevators, horizontal stabilizers, rudder, and vertical fin, removing certain bonding jumpers and installing new bonding jumpers, and replacing single-tabbed brackets with two-tabbed brackets. We are proposing this AD to detect and correct corrosion on bonding jumpers installed on the flight control surfaces, which, in the event of a lighting strike, could damage the actuator control electronics (ACEs) and result in the loss of the ability to command individual flight control surfaces or cause uncommanded motion of individual flight control surfaces.