What is the safe distance to operate vehicles to the rear of aircraft with engines running?

The correct distance to operate vehicles to the rear of aircraft with engines running is 200 feet. This safety measure is in place to protect vehicles and personnel from the hazards associated with jet blast and propeller wash. Aircraft engines can produce significant amounts of thrust, which can create strong winds capable of lifting and moving objects or vehicles situated too close. By maintaining a distance of 200 feet, you reduce the risk of being affected by these powerful aerodynamic effects, ensuring both safety for ground personnel and protection of equipment.

In an airfield environment, adhering to these distances is crucial for operational safety and efficiency, helping to avoid potential accidents and injuries. The other distances provided in the options are insufficient, as they do not account for the potential dangers posed by the engines' thrust in operation, thus compromising safety protocols.