On August 21, 2017, the US Navy destroyer John S McCain was overtaking the Liberian-flagged tanker Alnic MC while both vessels were transiting the westbound lane in the Middle Channel passage of the Singapore Strait Traffic Separation Scheme. The destroyer crew had a perceived loss of steering, and, while the crew attempted to regain control of the vessel, the John S McCain unintentionally turned to port into the path of the Alnic MC. At 0524, the vessels collided. As a result of the collision, 10 John S McCain sailors died, 48 were injured, and the vessel sustained over $100 million in damage. No one was injured on the Alnic MC, and the vessel sustained about $225,000 in damage. There was no report of pollution.

The National Transportation Safety Board determines that the probable cause of the collision between the destroyer John S McCain and the tanker Alnic MC was a lack of effective operational oversight of the destroyer by the US Navy, which resulted in insufficient training and inadequate bridge operating procedures. Contributing to the accident were the John S McCain bridge team’s loss of situation awareness and failure to follow loss of steering emergency procedures, which included the requirement to inform nearby traffic of their perceived loss of steering. Also contributing to the accident was the operation of the steering system in backup manual mode, which allowed for an unintentional, unilateral transfer of steering control.

As a result of this investigation, the National Transportation Safety Board makes new recommendations to the US Navy.