Under what condition will the Boost Pumps automatically operate?

The correct answer is that the Boost Pumps automatically operate during engine starting. This is because during engine start, ensuring an adequate fuel supply to the engine is critical. The boost pumps are designed to provide additional pressure to the fuel system, facilitating a smooth and successful start of the engine by preventing fuel starvation or vapor lock.

When the engine is being started, the boost pumps activate to provide a reliable flow of fuel from the tanks to the engine, as gravity alone may not be sufficient, especially in certain aircraft configurations where the fuel tanks are positioned in a way that does not allow for natural fuel flow.

Other conditions, such as cruise altitude or engine operational states, do not necessitate the automatic operation of boost pumps as they are primarily used to assist during starting and specific low fuel situations. The fuel quantity being above 70 lbs generally pertains to maintenance of adequate fuel levels rather than the direct trigger for pump operation. Turning off the landing lights would not influence the functioning of the boost pumps, as their operation is independent of other lighting systems in the aircraft.