Summary
We propose to supersede Airworthiness Directive (AD) 2013-01- 02, which applies to 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 Model 757- 200, -200PF, and -300 series airplanes. AD 2013-01-02 requires replacing the control switches of certain cargo doors. Since we issued AD 2013-01-02, additional un-commanded cargo door operation has been reported. This proposed AD would require replacement of certain cargo door control switches with a new improved switch; installation of an arm switch in certain cargo doors; operational and functional tests; and applicable on-condition actions. This proposed AD would also add airplanes to the applicability. We are proposing this AD to address the unsafe condition on these products.