Who is responsible for preparing the Weight and Balance document that must be on board?

The correct answer regarding who is responsible for preparing the Weight and Balance document that must be on board is that it is the operator of the aircraft. The operator is tasked with ensuring that the aircraft is loaded within the weight limits and that the center of gravity is within acceptable limits for safe flight. This responsibility includes preparing and maintaining the weight and balance data pertinent to specific flight operations.

The pilot in command does play a key role in ensuring that the weight and balance calculations are understood and adhered to, as they must check this information before flight, but the initial preparation and ongoing updates of this document fall under the scope of the operator's responsibilities. The manufacturer provides certification and specifications regarding weight and balance but is not involved in preparing these documents for each flight or operation. A designated officer of the airline may also have specific duties related to flight operations but does not have the overarching responsibility for the weight and balance documentation as designated to the operator.