Where is information found on acceptable wood substitutes?

The correct answer is significant because AC 43.13-1B provides specific guidance on acceptable materials, including wood substitutes, for aviation applications. This advisory circular serves as a critical resource for maintenance personnel and those involved in the airworthiness of aircraft. It details practices, materials, and standards that are acceptable to ensure safety and compliance with Federal Aviation Administration (FAA) regulations.

The other resources mentioned do not focus specifically on materials like wood substitutes for aviation uses. While they may provide valuable information on various aviation standards and practices, AC 43.13-1B is distinct in its practical application to maintenance and airframe repairs, making it the appropriate reference for this context. This emphasis on material standards is essential for ensuring that any substitute used meets the necessary safety and performance criteria in aviation operations.