AD NUMBER: 2018-19-23
PRODUCT: 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, 757-200PF, and 757-300 series airplanes.