Economical Repair of Damaged and Discrepant Holes in Metals and Composites

Damaged or discrepant holes in metal and composites aircraft are time consuming and expensive to repair. Bushing the hole back to nominal size using press or shrink fit bushings; often in conjunction with doublers or local riveted patches, are not very effective and can change the local stiffness of the structure. Using a cold expanded high interference ForceMate repair bushing is a more cost effective alternative that has the advantage of not altering the local stiffness or dynamic response of the repair location while locally cold working the surrounding material to enhance the life and damage tolerance of the repair. A ForceMate2 panel repair method has been adapted to repair elongated or oversized holes in thin panel structures or removable access panels. This paper describes the methods and discusses testing and evaluation done to qualify the repairs in structural or panel repair applications.