Which FAA-approved adhesive is commonly used in wood aircraft structures?

Resorcinol adhesive is commonly used in wood aircraft structures because it offers excellent strength and durability, making it well-suited for the rigorous demands of aviation applications. This adhesive forms a strong bond that is both water-resistant and capable of withstanding varying temperatures, which is vital for aircraft that are subject to changing environmental conditions during flight. Furthermore, resorcinol is recognized by the FAA, ensuring that its properties meet the necessary safety and performance standards crucial for aviation use.

In contrast, while other adhesives like epoxy, polyurethane, and contact adhesives have their specific advantages in various applications, they may not provide the same level of performance or regulatory approval for structural uses in aviation as resorcinol adhesive does. For instance, epoxy is often used for composite materials or in bonding other substrates, but it might not be as commonly recognized for wood structures in aviation. Polyurethane adhesives often have flexibility advantages but may not achieve the same strong bonds required for structural integrity. Contact adhesives, while useful for specific bonding tasks, do not typically provide the necessary strength and durability for critical load-bearing applications like those found in aircraft construction.