Immediately after the incident the U.S. Navy reports suggested a fatigued bridge crew, poor communication between crew members and crowded shipping lanes as the most likely culprits.
CNN quoted an unnamed "Navy official" stating that the ship lost steering control shortly before the accident but that "it was unclear why the crew couldn't use the ship's backup steering systems". On the same day as the collision between
John S. McCain and
Alnic MC,
the Pentagon ordered all fleet operations around the world to make a brief "operational pause" for safety checks during the following two weeks, as well as beginning a full safety review. Rear Admiral
Richard Brown was named to lead an internal investigation of the accident. Brown is a former commander of another sister ship, and currently serves as commander of Naval Personnel Command and deputy chief of Naval Personnel. On 18 September 2017, the new U.S. 7th Fleet commander,
Vice Admiral Phillip Sawyer, as part of the investigations into four surface ship incidents involving Navy ships in the Western Pacific in 2017, including the collision involving
John S. McCain, ordered that
Rear Admiral Charles Williams, Commander
Task Force 70, and Captain Jeffrey Bennett, commodore of
Destroyer Squadron 15, be removed from their positions due to a loss of confidence in their ability to command. On 10 October 2017,
John S. McCains commanding officer, CDR Alfredo J. Sanchez and executive officer, CDR Jessie L. Sanchez, were both relieved due to a loss of confidence. A statement from U.S. 7th Fleet Public Affairs stated that "while the investigation is ongoing, it is evident the collision was preventable, the commanding officer exercised poor judgment, and the executive officer exercised poor leadership of the ship’s training program."
Initial US Navy report On 1 November 2017, the US Navy issued a "Memorandum for distribution". The memorandum defines the legal privilege of such reports, but in the interests of transparency authorizes the release of the two reports covering collisions of
Fitzgerald and
John McCain. The two reports are annexed to the memorandum. The reports are intended to be authoritative, but are not balanced; they specifically exclude a detailed examination of the actions of and
Alnic MC respectively. The report for
John S. McCain detailed the following; • On 20 August, navigation briefs were prepared for the transit of the Singapore Strait and rudder swing checks were performed. Shortly after midnight, a log entry revealed that one radar was inoperable. • After 01:00, more frequent position checks were recorded as the ship approached the straits and the Commanding Officer (CO) was on the bridge. • At 02:16, the ship's propulsion configuration was changed. Normally the two propeller shafts are controlled as one at the Ship's Control Console (SCC), but for increased maneuverability, they can be separated so that the port and starboard shafts are each controlled by its own throttle. • At 04:18, the ship changed to "Modified Navigation Detail", in which additional watchstanders were present on the bridge. This was normal for a U.S. Navy ship when approaching within of shallow water. • From 04:27, the position was determined and logged at 5-minute intervals. • At 04:36, the ship switched from automatic to manual control of steering. Various changes of course were required to avoid shipping, but they were not logged. • At 04:54, there was radar contact with
Alnic MC, ahead at a range of under . •
John S. McCain continued to make small alteration of course to avoid other vessels and by 05:18 was running at on a bearing of 230T. To keep this course against a tidal stream, she was carrying between 1 and 4 degrees of right rudder. • At 05:20:39, control of the helm passed to the lee helm position, the change bringing the rudder amidships. • At 05:20:47, the lee helm also took control of the port shaft. • At 05:21, the lee helm reported that he had lost steering and the conning officer ordered steering control to the offline steering units and the aft control position was ordered to be crewed. Port and starboard steering were transferred to the aft position at 05:21:13 and 05:21:15, respectively. • At 05:22, the ship was turning to port and the CO ordered the external lights to be changed to "ship not under command", a warning to all vessels that the Navy ship could not control her course. • Over the next minute, the lee helm took control of the starboard shaft, not realizing that the port throttle was uncoupled. The CO ordered a reduction in speed, but only the port propeller was slowed, thereby increasing the turn to port. • The executive officer warned the CO that the ship was not slowing, so the CO ordered a further reduction in speed, increasing the rate of turn. The CO should have announced that he was personally taking control of maneuvering, but failed to do so. The ship's
user interface was found to have contributed to the sailors' confusion. At no point did either ship sound a warning signal of five short blasts on the whistle (Colregs rule 34(d)) or attempt to contact the other via VHF radio. The report describes the actions taken in the aftermath of the collision. On page 49 it states that the external lights were changed to "red over red" ("vessel not under command"), but the timeline on page 65 claims that this was done at 05:22, at least a minute before the collision. The report criticizes
John S. McCain under two headings: "Seamanship and Navigation" and "Leadership and Culture". The former heading mentions that a higher state of readiness was required in congested waters, that the "Sea and Anchor" detail should have been set earlier and that both vessels failed to sound the required signals or use VHF. The latter heading contains criticisms about the ship's organization. Specifically the CO did not set the Sea and Anchor watch, watchstanders had not attended the navigation brief, leadership failed to assign sufficient experienced officers, the CO issued unplanned orders which were not communicated to the watch officers, who in turn failed to provide input and backup to the CO.
NTSB accident report On June 19, 2019, the
National Transportation Safety Board (NTSB) released their report on the accident. Their finding that the probable cause of the incident was a "lack of effective operational oversight of the destroyer by the US Navy, which resulted in insufficient training and inadequate bridge operating procedures." Along with their complete report they provided a series of recommendations including changes to Navy bridge equipment and training procedures. This is the first independent investigation document released on any of the recent US Navy navigation incidents. ==Transport to Yokosuka==