What is required when parking a vehicle at the side of any aircraft?

Answer: B — Vehicle must be visible to personnel in the cockpit

When parking a vehicle at the side of any aircraft, it is essential that the vehicle must be visible to personnel in the cockpit. This requirement is in place primarily for safety reasons. Visibility ensures that the flight crew and ground personnel can see all vehicles parked near the aircraft, which helps to prevent accidents and ensures safe operations on the airfield. This practice minimizes the risk of collisions and enhances communication between ground crew and cockpit personnel. It can potentially prevent situations where a vehicle moving in close proximity to the aircraft could endanger both the aircraft and the vehicle occupants. In contrast, parking a vehicle under the wing would obstruct visibility, increasing the risk of accidents and potentially interfering with the aircraft's operations. Blocking the wingtip area could lead to similar safety issues, while being within 10 feet does not address visibility concerns, significantly compromising safety protocols. Thus, ensuring visibility from the cockpit is the correct and safest approach when parking near an aircraft.