AD FAA-2012-0804

We are superseding an existing airworthiness directive (AD) for certain The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes; and certain Model 757-200, -200PF, and -300 series airplanes. That AD currently requires replacing the control switches of the forward, aft, and nose cargo doors of Model 747 airplanes; and requires replacing the control switches of cargo doors 1 and 2 of Model 757 series airplanes. This new AD adds airplanes to the applicability and revises the initial compliance times for those airplanes. This AD was prompted by reports of problems associated with the uncommanded operation of cargo doors. We are issuing this AD to prevent injuries to persons and damage to the airplane and equipment.