PRODUCT: Certain The Boeing Company Model 777-200 and -300 series airplanes SUBJECT: Airworthiness Directive 2012-08-13 ACTION: Final Rule
SUMMARY: This AD was prompted by reports of two failures of the single-tabbed bracket on the rudder. This AD requires replacing certain single-tabbed bonding brackets in the airplane empennage with two-tabbed bonding brackets. This AD also requires, for certain airplanes, installing new bonding jumpers, and measuring the resistance of the modified installation to verify resistance is within specified limits.
The FAA is issuing this AD to prevent failure of the bonding jumper bracket, which could result in loss of lightning protection ground path, which could lead to increased lightning-induced currents and subsequent damage to composite structures, hydraulic tubes, and actuator control electronics. In the event of a lightning strike, loss of lightning ground protection could result in the loss of control of the airplane.