Why is moisture control critical in the use of wood for aviation?

Moisture control is essential in the use of wood for aviation primarily because it directly affects the wood's structural integrity and can prevent degradation. Wood is a hygroscopic material, meaning it absorbs and releases moisture depending on the environmental conditions. If moisture levels fluctuate excessively, the wood can swell, warp, or crack. These changes can significantly compromise the strength and reliability of wooden components in an aircraft, which must adhere to strict safety and performance standards.

Additionally, excessive moisture can lead to biological degradation, such as mold or rot, which further weakens the wood and can have severe implications in aviation, where structural failure is not an option. Maintaining proper moisture levels helps ensure that the wood maintains its desired mechanical properties, providing the necessary strength and durability required in aviation applications.