How is lightning protection integrated into a composite aircraft structure?

How is lightning protection integrated into a composite aircraft structure?

• A. A layer of conductive material embedded in the composite
• B. An external metal skin
• C. A dedicated lightning protection system
• D. No protection is required

Answer: (A)

Lightning carries a lot of current and, in a composite, the resin matrix isn’t conductive. To protect the structure, a conductive path must be embedded into the laminate so the current can be spread out and carried away to ground rather than concentrating at a single point. The common approach is to integrate a layer of conductive material—like copper or aluminum foil or a woven mesh—directly within the composite layup. This embedded layer becomes part of the aircraft’s lightning path, providing a low-impedance route that redirects the current across a large area and toward bonding networks, reducing heating, resin damage, and fiber fracture. External skins or separate protection systems can be used in some designs, but the embedded conductive layer is the typical method that makes protection intrinsic to the composite structure.

Lightning carries a lot of current and, in a composite, the resin matrix isn’t conductive. To protect the structure, a conductive path must be embedded into the laminate so the current can be spread out and carried away to ground rather than concentrating at a single point. The common approach is to integrate a layer of conductive material—like copper or aluminum foil or a woven mesh—directly within the composite layup. This embedded layer becomes part of the aircraft’s lightning path, providing a low-impedance route that redirects the current across a large area and toward bonding networks, reducing heating, resin damage, and fiber fracture. External skins or separate protection systems can be used in some designs, but the embedded conductive layer is the typical method that makes protection intrinsic to the composite structure.