What does the basic empty weight include in weight and balance computations?

The basic empty weight is a critical term in weight and balance computations as it provides a baseline for determining how much additional weight the aircraft can carry, including passengers and cargo. The correct answer highlights that the basic empty weight encompasses the airframe, engine(s), and any installed optional equipment. This includes every element that is permanently attached to the aircraft, such as avionics, seats, and other features that influence the aircraft's performance but do not include operational fuel or payload.

Understanding this definition is crucial for pilots and aircraft operators because it allows them to accurately assess the aircraft's performance under varying load conditions and ensures safety by preventing overloading. Knowing the basic empty weight helps in calculating the maximum allowable weight and ensures the aircraft remains within safety limits during operation. This comprehensive view is essential for flight planning and ensuring compliance with regulations pertaining to weight and balance.