Question id 51 - Mass and Balance - ATPL - Airline Transport Pilot license

The loading manifest. It differs from Dry Operating Mass by the value of the 'useful load'.
The weighing schedule. If changes occur, due to modifications, the aircraft must be re-weighed always.
The loading manifest. It differs from the zero fuel mass by the value of the 'traffic load'.
The weighing schedule and is amended to take account of changes due to modifications of the aircraft.