Carbon Fiber + Aluminum + Water = Corrosion. Are The Panels Properly Sealed?

October 2021

Carbon fiber is becoming very prevalent in the manufacturing of business aircraft. It is significantly lighter in weight and greater in structural strength than aluminum and steel. It is used to construct aircraft panels, fairings, floorboards, and afterbody skins, among other components. When in use, these components often are in contact and sealed to the aluminum fuselage and other aluminum structures.

Preventive Maintenance

If water is allowed to penetrate the seal between carbon fiber (panels, fairings, or floorboards) and aluminum (fuselage), it creates a battery-like environment and can becomes highly corrosive. To prevent exposure to moisture, it is good practice to visually inspect the edges of carbon fiber panels regularly to ensure they remain adequately sealed.

Bubbling paint along panel edges is a classic sign that corrosion is present. Do not ignore it. Corrosion that is ignored will not go away. It just continues to grow and cause extensive damage that will be expensive to repair.

Major Inspections

During any maintenance inspection or paint process where aircraft panels are removed, be aware of the procedures of how they are sealed when put back in place. A dry seal should be applied between the panels and the panels should be edge sealed. If the fairings are not removable then verify that they are sealed from the environment.

Finding corrosion during a visual check or major inspection is inevitable. Still, it doesn’t have to be detrimental if correctly identified and taken care of by a full-service MRO like Duncan Aviation.