What must the pilot in command ensure regarding flight plans for USAF aircraft?

The pilot in command of USAF aircraft is required to file a flight plan for any flight involving these aircraft. This requirement ensures that the mission is conducted safely and with proper oversight. Filing a flight plan allows for effective coordination with air traffic control, enhances situational awareness, and ensures that search and rescue operations can be initiated swiftly if an aircraft fails to arrive at its destination. This process is essential regardless of the mission's nature or the weather conditions, emphasizing the commitment to safety and operational discipline within the USAF. The other options fail to recognize the stringent protocols that govern military aviation operations, where flight plans are vital for safety and mission success.