What altitude does the jet route system extend to?

The jet route system is designed to facilitate high-altitude flight primarily for jet aircraft, providing them with a safe and efficient navigation network. The correct altitude range for the jet route system extends up to Flight Level 450 (FL450), which corresponds to an altitude of approximately 45,000 feet. This height is suitable for high-speed, high-altitude jet operations, offering a structured route system that enhances traffic flow and safety at these elevations.

In contrast, other altitudes mentioned do not fit the operational requirements for jet routes. For instance, altitudes up to FL300 (approximately 30,000 feet) and FL400 (around 40,000 feet) are lower than the upper boundary for jet routes, which limits the operational scope needed for more advanced jet aircraft. Additionally, the option of up to 10,000 feet is well below the operational range of the jet route system, where the primary focus is on air traffic that operates significantly higher. Thus, the altitude of FL450 is essential for ensuring that jet aircraft can effectively utilize these routes, promoting efficient navigation and safety.