Airworthiness Directives; McDonnell Douglas Model DC-8 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-8 series airplanes that have been converted from a passenger- to a cargo-carrying ("freighter") configuration. This amendment requires, among other actions, modification of the main deck cargo door structure and fuselage structure; modification of a main deck cargo door hinge; modification of the main deck cargo floor; and installation of a main deck cargo 9g crash barrier. These actions are necessary to prevent opening of the cargo door while the airplane is in flight or collapse of the main deck cargo floor, and consequent rapid decompression of the airplane including possible loss of flight control or severe structural damage. These actions are intended to address the identified unsafe condition.