What is the operating range for propeller operation while on the ground?

The correct choice indicates that the operating range for propeller operation while on the ground is between 62-80% Np. This range is significant because it represents the optimal settings for engine performance and efficiency during ground operations, such as taxiing or run-up procedures, without risking damage to the propeller or engine.

Operating within this range ensures that the propeller generates sufficient thrust while also maintaining appropriate engine speeds for safe operation. This range balances performance needs with safety considerations, as it helps avoid excessive wear or overheating that could occur at either too low or too high settings.

In contrast, the other ranges provided do not align with the operational needs during ground maneuvers. Higher ranges could lead to unnecessary strain on the propeller and engine, while ranges that are too low may not provide enough thrust for effective ground control. Thus, the selection of 62-80% Np reflects a well-considered standard for maintaining both efficiency and safety during ground operations.