Composite materials offer many advantages over conventional materials in structural reinforcement and repair of aging aircraft. Composite repair patches are usually boron/epoxy or carbon/epoxy laminates adhesively bonded to the aluminum substrate where damage, such as fatigue or stress corrosion cracking, exists or is anticipated. Such patches are thin and lightweight, conform to curved surfaces and have high directional strength and stiffness. They can be installed relatively easily without causing damage to the existing structure and they do not cause any problems with fretting, corrosion, undesirable structural changes or balance.