Airworthiness Directives; The Boeing Company Model 777-200 and -300 Series Airplanes

Résumé

We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 777-200 and -300 series airplanes. This proposed AD would require replacing certain single-tabbed bonding brackets in the airplane empennage with two-tabbed bonding brackets. This proposed AD would also require, for certain airplanes, installing new bonding jumpers, and measuring the resistance of the modified installation to verify resistance is within specified limits. This proposed AD was prompted by reports of two failures of the single- tabbed bracket on the rudder. We are proposing 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.