What device prevents rotation of the propeller during a casualty?

What device prevents rotation of the propeller during a casualty?

• A. Main engine locking device
• B. Propeller shaft brake
• C. Emergency stop switch
• D. Thrust collar

Answer: (A)

The main engine locking device is designed specifically to prevent rotation of the propeller in the event of a casualty. This device secures the engine to stop propeller movement when needed, ensuring the safety of personnel and preventing further damage to equipment. It effectively locks the main engine in a specific position, which is critical during emergencies or failures. The propeller shaft brake, while also capable of preventing rotation, typically works in conjunction with normal operations rather than solely in emergency situations. The emergency stop switch provides a way to cut off power to the engine quickly but does not inherently lock the propeller in place. Lastly, the thrust collar allows for the transmission of thrust while supporting axial loads, but it does not prevent rotation in the way that a locking device does. Thus, the main engine locking device is the optimal choice for preventing propeller rotation during a casualty.

The main engine locking device is designed specifically to prevent rotation of the propeller in the event of a casualty. This device secures the engine to stop propeller movement when needed, ensuring the safety of personnel and preventing further damage to equipment. It effectively locks the main engine in a specific position, which is critical during emergencies or failures.

The propeller shaft brake, while also capable of preventing rotation, typically works in conjunction with normal operations rather than solely in emergency situations. The emergency stop switch provides a way to cut off power to the engine quickly but does not inherently lock the propeller in place. Lastly, the thrust collar allows for the transmission of thrust while supporting axial loads, but it does not prevent rotation in the way that a locking device does. Thus, the main engine locking device is the optimal choice for preventing propeller rotation during a casualty.