Which type of grain is preferred in aircraft-quality wood?

In the context of aircraft-quality wood, straight grain is preferred due to its superior strength and stability. Straight-grained wood tends to have a uniform texture and is less likely to contain knots or other imperfections that can compromise the integrity of the material. This straight grain alignment allows for predictable and consistent mechanical properties, which are crucial in aviation applications where reliability and performance are paramount.

Using straight-grained wood minimizes the risk of warping and splitting, characteristics that can lead to failure under stress. In contrast, other grain types, such as spiral, curly, or wavy, may introduce variations in strength and stability, making them less suitable for aviation purposes. For instance, spiral grain can lead to unpredictable performance under load, while curly grain and wavy grain can affect flexibility and strength. Therefore, straight grain is specifically chosen for its structural advantages, ensuring that the aircraft components made from it maintain their integrity under various conditions.