Under which condition may passengers board if an engine is running?

• A. Passengers may board if the engine on the same side as the door is running.
• B. Passengers may board if the engine on the opposite side is running and an escort is provided.
• C. Passengers may board only after aircrew signals and doors closed.
• D. Passengers may board when both engines are running without escort.

Answer: (B)

When an engine is running, boarding is allowed only under controlled conditions to protect passengers from propeller and engine-area hazards. The safe scenario is that the engine on the opposite side from the door is running, and an escort is provided to supervise the boarding, guide passengers away from the propeller arc, and ensure the door and path are clear. This escort ensures a trained crew member is directing people and can stop boarding if anything unsafe is observed. Having the engine on the same side as the door running would place the propeller and intake directly beside the boarding area, increasing risk and not meeting the safeguard requirement. Likewise, boarding with both engines running but without an escort, or relying only on aircrew signals and doors being closed, does not provide the necessary supervision of the hazardous conditions around a running engine.