What is the Taxi Mass (TM) of an aircraft?

The Taxi Mass (TM) of an aircraft is defined as the mass of the aircraft before engine start. This measurement is critical as it considers everything onboard at that specific moment, including the aircraft's structure, fuel, passengers, cargo, and any additional equipment that is not yet in operation.

Understanding this concept is particularly important for flight planning and ensuring that the aircraft is within weight limits prior to any taxiing activities. As such, it serves as a foundational element in calculating other vital mass metrics, such as takeoff mass and landing mass.

It is essential to note that the Taxi Mass is established before any engines are started because engine operation can introduce several variables affecting the aircraft's weight, such as fuel flow regulations or the need to account for additional systems being activated.