What should you do after the aircraft has stopped if there is a brake failure?

When faced with a brake failure after the aircraft has stopped, the primary action to take is to chalk the main landing gear. This is crucial for ensuring the aircraft remains stationary and does not roll unexpectedly. Chalking the wheels serves as a physical safety measure to prevent any unintended movement, especially when there is uncertainty about the effectiveness of the braking system.

While engaging the parking brake, inspecting the brake system, or shutting down the engines may seem beneficial, they do not provide the immediate safety required to secure the aircraft on the ground. In a brake failure scenario, securing the aircraft is the top priority, hence why chalking the wheels is the most appropriate action to take first.