Who must determine the suitability and durability of materials used in a Part 23 airplane?

The suitability and durability of materials used in a Part 23 airplane is the responsibility of the applicant. In the context of aircraft manufacturing and certification, the applicant is typically the individual or entity seeking to gain type certification for the aircraft. This includes ensuring that all materials used in the construction of the aircraft meet the relevant safety standards and design criteria set forth by the FAA.

The applicant must provide comprehensive data and evidence that demonstrate the materials used can withstand the operational environments and stresses encountered during flight. This is critical to ensuring the overall airworthiness of the aircraft. By determining the suitability and durability of materials, the applicant submits their findings and analyses as part of the certification process, allowing them to meet regulatory requirements and confirm the aircraft’s safety.

While the aircraft manufacturer and FAA play significant roles in the oversight and regulation of these processes, it is ultimately the applicant's responsibility to ensure that the chosen materials are appropriate for the intended design and usage of the aircraft.