Which of the following types of wood is NOT commonly used in aircraft construction?

In aircraft construction, the types of wood commonly used include plywood, laminated wood, and solid wood, which are chosen for their specific properties that contribute to the strength and lightweight characteristics desired in aviation applications.

Hardwood, while it can certainly be utilized in various woodworking projects and certain specialized applications, is not typically used in aircraft construction due to its density and weight compared to other forms of wood. Aircraft materials must strike a balance between strength and weight, and hardwood generally does not meet the requirements as effectively as plywood or laminated wood, which are specifically engineered to provide the necessary durability without excessive weight. Plywood and laminated woods also offer additional benefits such as improved resistance to warping and cracking, which are critical in the dynamic environment of an aircraft.