Trainer Helicopter, Design Number 73 (TH-73) Systems Practice Test

The rotor brake on the TH-73 functions through a flexicable system that is paired with an independent hydraulic pump and self-contained reservoir, along with brake calipers. This design allows for effective braking of the main rotor blades when the helicopter is on the ground, ensuring that the blades can be safely stopped without relying on other systems or external sources.

The independent hydraulic pump generates the necessary hydraulic pressure to engage the brake calipers. This allows for precise control over the braking action, enhancing safety and operational efficiency while the helicopter is stationary. The self-contained reservoir ensures that there is always sufficient hydraulic fluid available for the braking system to function properly, even if the helicopter is not in operation.

In contrast, other methods described in the incorrect options either do not relate to the operating principles of the TH-73 rotor brake or do not offer the same level of operational efficacy or efficiency required for stopping the rotor blades safely on the ground.