From what altitude does the jet route system start?

The jet route system begins at an altitude of 18,000 feet Mean Sea Level (MSL). This is significant in air traffic management as it establishes a clear separation between high-altitude jet operations and the lower airspace, which is occupied by general aviation and other aircraft that may not operate at those higher altitudes.

At 18,000 feet MSL and above, aircraft are typically flying on federally designated airways that facilitate efficient and safe navigation for jet traffic. These routes are specifically designed to accommodate high-speed, high-altitude flights, which are commonly utilized by commercial airlines and other jet aircraft. This also marks the transition into controlled airspace where specific air traffic control procedures and regulations come into effect, contributing to enhanced safety and organization within the airspace system.

In contrast, altitudes below 18,000 feet are generally regarded as lower airspace, which serves a different set of flight operations and may have different rules and regulations that apply to aircraft flying within that region. Understanding this altitude is crucial for pilots and air traffic controllers alike for maintaining the flow of air traffic and ensuring the safety of all airspace users.