Which of the following is NOT a consideration for APU operational time?

The consideration that is not relevant to APU operational time is the wingspan of the aircraft. The APU (Auxiliary Power Unit) is primarily concerned with the operational environment and requirements for its performance and reliability. Factors such as temperatures and fuel levels are critical because they directly influence how long the APU can operate effectively. High temperatures might lead to overheating, while adequate fuel levels are necessary for the APU to function continuously.

Maintenance intervals are also essential, as they dictate how often the APU should be serviced to maintain optimal performance and prevent failure. However, the wingspan of the aircraft does not affect the APU's operational time, as it relates more to the aircraft's maneuverability, loading capabilities, and general design rather than to the APU's function or requirements. Thus, while the other factors are directly tied to the APU's usage and efficiency, wingspan does not play a role in determining how long the APU can operate.