ABSTRACT
Repairs to adhesive-bonded aluminum aircraft structure are required as a result of mechanical damage on the manufacturing or flight line and also as a result of in-service problems. The in-service repair of adhesive-bonded aluminum aircraft structure has, as its primary concern, the safety and dependability of the aircraft. The aircraft operator is given a structural repair manual by the aircraft manufacturer, which usually conservatively estimates the damage tolerance of the adhesive-bonded structures. Aluminum adhesive-bonded structure on aircraft in commercial service rarely fails in a cohesive manner. The autoclave is used for repair purposes when the amount of damage to an adhesive-bonded part is extensive enough to require partial or complete rebuilding. New developments within the United States to ensure the environmental stability of the bonding surface consist of anodizing in a solution of phosphoric acid. The use of primers is recommended to improve durability and to minimize contamination prior to adhesive cure.
