Airworthiness Directives; Boeing Model 707-100 Long Body, -100B Long Body, -100B Short Body, -E3F, -300, -300B, and -300C Series Airplanes; Model 727-100 and -200 Series Airplanes; Model 737-200, -200C, -300, -400, and -500 Series Airplanes; Model 747-100B, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747SR, and 747SP Series Airplanes; Model 757-200 and 757-200PF Series Airplanes; and Model 767-200 and -300 Series Airplanes; Equipped With Observer or Attendant Seats

The FAA is superseding two existing airworthiness directives (AD), which apply to certain Boeing airplanes as specified above. Those ADs currently require inspection of the attachment of the shoulder restraint harness to the mounting bracket on certain observer and attendant seats to determine if a C-clip is used in the attachment, and corrective action if necessary. This new AD removes certain airplanes from the applicability of one existing AD and adds other airplanes. We also determined that this new AD refers to identical revisions of certain service information cited by another existing AD. This AD results from the determination that some airplanes had been inadvertently included in or excluded from the applicability of one existing AD and that certain additional new airplanes are now subject to the identified unsafe condition. We are issuing this AD to prevent detachment of the shoulder restraint harness of the attendant or observer seat from its mounting bracket during service, which could result in injury to the occupant of the seat.