Which UAS is noted for having a flight duration of over 16 hours?

The correct answer is the Global Hawk, which is a high-altitude, long-endurance unmanned aerial system (UAS) capable of staying aloft for more than 16 hours. This impressive flight duration allows it to conduct extensive surveillance and reconnaissance missions without the need for frequent landings or refueling, making it a strategic asset in both military and intelligence operations.

The Global Hawk's extended endurance is primarily attributed to its design, which includes a highly efficient engine, aerodynamic features, and the ability to operate at high altitudes. This enables it to cover vast areas and gather critical intelligence over prolonged periods in a single mission.

In contrast, while the RQ-5A Hunter, Predator, and Reaper UAS all have significant capabilities, none provide the same level of extended flight duration as the Global Hawk.