All the following would typically be considered indirect costs of manufacturing a
particular Boeing 747 to be delivered to Singapore Airlines: electricity to run production equipment, the factory manager's salary, and the cost of the General Electric jet engines installed on the aircraft.

Electricity to run production equipment and the factory manager's salary are indirect costs because they cannot be directly traced to the production of a specific Boeing 747. However, the cost of the General Electric jet engines installed on the aircraft is a direct cost, as it can be directly attributed to the manufacturing of that specific airplane.