What are the at least three positions of the fuel selector valve in a multi-engine aircraft?

In a multi-engine aircraft, the fuel selector valve typically has positions that allow for optimal fuel management during flight, which includes ON (fuel flow from the selected tank), OFF (no fuel flow), and Crossfeed (allowing fuel to flow from one tank to the other engine).

The ON position allows the engine to draw fuel from the specified tank, ensuring that it receives the necessary fuel supply for operation. The OFF position is essential for shutting off fuel flow during certain situations, such as maintenance or emergency procedures, to prevent fuel leaks and ensure safety. The Crossfeed position is particularly important in multi-engine aircraft as it enables the aircraft to draw fuel from the tank of another engine, providing flexibility in fuel management and enhancing operability in case one engine's fuel supply becomes compromised or depleted.

The other choices, while they might mention relevant concepts, do not fully capture the critical operational positions of a fuel selector valve in a multi-engine setting. This is why their definitions don’t fit the typical nomenclature or functions associated with multi-engine fuel systems.