What is the primary role of a wheel brake assembly?

The primary role of a wheel brake assembly is to slow or stop the aircraft. When the aircraft lands, the wheel brakes engage to create friction against the wheels, which helps reduce the aircraft's speed effectively. This is crucial for safe landing operations and controlling the aircraft during taxiing.

The wheel brake assembly is an essential component in the overall safety and performance of an aircraft, ensuring that it can efficiently come to a complete stop when required. This function is vital for the management of the aircraft’s inertia and for meeting operational requirements during landing and ground movement.

Other options, while related to aircraft operations, do not accurately represent the primary function of the wheel brake assembly. For instance, assisting in takeoff is not a role of the brake system, which is mainly engaged during landing and ground handling. Additionally, maintaining hydraulic pressure relates more to the hydraulic system in general rather than the specific function of the brakes. Lastly, controlling engine RPM pertains to the engine's performance management rather than the braking system itself. Therefore, the correct understanding of the wheel brake assembly’s role is firmly rooted in the function of slowing or stopping the aircraft.