Note: Be careful to avoid any double mass calculations, due to the fact that some masses are already included in other masses, e.g. baggage and catering masses are included in TL and DOM respectively.

Take-off mass (TOM) is the mass of the aeroplane at the start of the take-off run. It is equal to the Zero Fuel Mass (ZFM) plus the take-off fuel (T/O fuel).

ZFM is the total mass of the aircraft not considering the usable fuel and is equal to the Dry Operating Mass (DOM) plus the traffic load (TL).

DOM is the basic empty mass and the variable load (VL). The VL consists of the crew, their baggage and any removable equipment required for the flight, such as catering, service equipment, food, lavatory chemicals.

Traffic Load is the total mass of passengers, baggage, cargo and any carry-on specialist equipment including any ballast. TL may include "non-revenue" load, such as spare parts and positioning crew.

Thus, the TOM is equal to: ZFM + T/O fuel =

• DOM + TL (34 000 kg + 13 000 kg)
• + Trip fuel + Final Reserve Fuel + Alternate fuel + Contingency (1800 kg + 1225 kg + 1400 kg + 90 kg)
• = 51 515 kg.