Airworthiness Directives; The Boeing Company Airplanes

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-400, 747-400D, and 747-400F series airplanes; Model 757 airplanes; and Model 767-200, -300, -300F, and - 400ER series airplanes. This AD was prompted by reports of uncommanded autopilot engagement events resulting in incorrect stabilizer trim adjustment during takeoff. This AD requires, depending on the model/ configuration, installing an on-ground stabilizer autotrim inhibit system, relays and related wiring to open and close the flight control computer (FCC) analog output, and new operational program software (OPS) into the FCCs. We are issuing this AD to address the unsafe condition on these products.