Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 727 series airplanes that have been converted from a passenger to a cargo-carrying (``freighter'') configuration. This proposal would require limiting the payload on the main cargo deck by revising the Limitations Sections of all Airplane Flight Manuals (AFM), AFM Supplements, and Airplane Weight and Balance Supplements for these airplanes. This proposal also provides for the submission of data and analysis that substantiates the strength of the main cargo deck, or modification of the main cargo deck, as optional terminating action for these payload restrictions. This proposal is prompted by the FAA's determination that unreinforced floor structure of the main cargo deck is not strong enough to enable the airplane to safely carry the maximum payload that is currently allowed in this area. The actions specified by the proposed AD are intended to prevent failure of the floor structure, which could lead to loss of the airplane.