When assessing wood defects, which is a primary concern?

When evaluating wood defects in aviation applications, knots and splits are a primary concern due to their significant impact on the wood's structural integrity and mechanical properties. Knots can create localized stress concentrations that might weaken the material, making it inappropriate for load-bearing applications. Similarly, splits, which are fractures in the wood, can compromise its strength and durability. In the context of aviation, where reliability and safety are paramount, any potential weaknesses introduced by these defects must be carefully considered.

While surface finish, color, and grain direction can affect aesthetics and some functional characteristics, they do not pose the same level of risk to structural integrity as knots and splits do. For example, a wood piece could have an excellent surface finish and attractive color but still be unsuitable for structural use if it contains serious defects like knots or splits. Therefore, assessing knots and splits is essential when determining the wood's suitability for aviation applications.