How quickly can the rotor brake stop the rotors from 100% in an emergency?

The rotor brake is a critical component used to quickly reduce rotor speed in an emergency situation, preventing potential damage or hazards associated with high-speed rotor operation. When the rotors are turning at 100% RPM, applying the rotor brake can safely stop the rotors within a specific time frame.

In this case, the correct answer indicates that the rotor brake can effectively stop the rotors in approximately 20 seconds under emergency conditions. This time frame is designed to balance the need for rapid deceleration with the structural integrity of the rotor system. Halting the rotors too quickly could result in mechanical stress or damage, so the specification of 20 seconds reflects an engineered response that maximizes safety and efficacy.

This understanding is foundational for operational readiness, as crew members must be aware of the capabilities and limitations of the rotor brake system during emergency procedures.