Boeing 737 Fuselage Structural Integrity Program

Early Boeing 737's were manufactured using a cold structural adhesive bonding process to attach internal doublers to the fuselage skin and to supplement rivets at the skin lap splices. The doublers carry loads and perform a fail-safe tear-stopping function. Failures of the adhesive bond have been found in some of the cold bonded components jeopardizing the design integrity of the fuselage pressure vessel. This paper examines the problem, service experience, and modifications currently being made to restore structural integrity; and relates these modifications to the other required elements in the current solution to the “Aging Aircraft Problem”.