Which statement best describes the purpose of wheel chocks during aircraft servicing?

• A. They improve aerodynamics during servicing.
• B. They prevent unintended movement due to engine vibrations, gusts, or hydraulic pressure while servicing.
• C. They provide a temporary parking brake for aircraft.
• D. They are not necessary if the aircraft is in park.

Answer: (B)

Wheel chocks immobilize an aircraft on the ground to prevent it from rolling while work is being done or when it’s exposed to gusts, engine vibrations, or hydraulic pressures in the system. They work by wedging against the tire so the wheel can’t rotate, providing a physical barrier to movement. They’re used in addition to the parking brake because they don’t provide braking action themselves; they merely keep the aircraft from moving. They’re not optional just because the aircraft is parked, and they aren’t a substitute for the brake system. Remove them before taxiing or flight.