What does an MTR with a number 3 signify?

An MTR, or Military Training Route, designated with a number 3 indicates that the routes are intended for use at altitudes above 1,500 feet AGL (Above Ground Level). This classification is significant as it helps both military and civilian pilots understand the operational parameters of the training routes. MTRs number 3 are typically utilized for higher altitude maneuvers, allowing aircraft to engage in training exercises and operations safely without interfering with low-altitude air traffic.

The focus on these routes being above 1,500 feet AGL is essential for maintaining safety and airspace management, ensuring that military training does not conflict with other low-altitude airspace users. Understanding these designations helps in flight planning and enhances situational awareness for all pilots operating in the vicinity of these designated routes.