What flight rules apply to Military Training Routes above 1,500 feet AGL?

Military Training Routes (MTRs) are established specifically for military aircraft to conduct training operations, often at higher airspeeds and altitudes than typical civil operations. When these routes are above 1,500 feet AGL (Above Ground Level), the flight operations predominantly adhere to Instrument Flight Rules (IFR).

Under IFR, pilots must operate in accordance with rules that are primarily designed for conditions where visibility is low or an aircraft is flying in controlled airspace. This allows for the safe integration of military operations into the national airspace while also ensuring that civilian air traffic can operate safely. MTRs are designated for military use but must still comply with the regulatory framework that governs flight operations, making IFR the appropriate set of rules for aircraft flying on these routes above 1,500 feet AGL.

Understanding this context clarifies why IFR is the pertinent choice: it ensures adherence to regulations that promote safety and efficiency in areas that might see a mix of military and civilian air traffic. Meanwhile, the other options refer to flight rules that may not accurately represent the necessary protocols for military operations on these designated routes.