What malfunction would be noted by excessive aircraft rollback following BAK-12 engagement?

Excessive aircraft rollback following BAK-12 engagement indicates a cam out of index. The BAK-12 is a type of aircraft arrestor system designed to safely decelerate an aircraft during landing. When the cam mechanism is correctly indexed, it allows the system to engage properly and effectively stop the aircraft by applying brakes through the arrestor wires.

If the cam becomes out of index, it means that the alignment and positioning have been disrupted, which can lead to insufficient engagement of the arrestor system. As a consequence, the aircraft may not decelerate as needed, resulting in excessive rollback after the wires are engaged. This condition directly impacts the effectiveness of the arrestment, leading to the described failure to halt the aircraft in a timely manner. Proper indexing of components is critical for the system to function as intended.