Braking apparatus and method for an aerial refueling boom system

A braking apparatus of an aerial refueling boom system is provided to reduce the likelihood of or to prevent anomalous boom extension. The braking apparatus includes a pulley about which a cable wraps. The pulley is configured to be operably mounted to a first tube of the boom system and to rotate in response to movement of a second tube relative to the first tube as a result of the connection of the cable to the second tube. The braking apparatus also includes a lock, such as a brake or a pin lock, having open and actuated positions. In the actuated position, rotation of the pulley and movement of the second tube relative to the first tube are prevented. The lock is configured to be actuated by a reduction in performance of an actuation source that otherwise controls the relative positions of the first and second tubes.