USS John S. McCain and Alnic MC collision

On 1 November 2017, the US Navy issued a "Memorandum for distribution".[23] 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 ACX Crystal 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.[24]
• 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 10 nautical miles (19 km; 12 mi) of shallow water.[25]
• From 04:27, the position was determined and logged at 5-minute intervals.[26]
• 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 8 nautical miles (15 km; 9.2 mi).
• John S. McCain continued to make small alteration of course to avoid other vessels and by 05:18 was running at 20 knots (37 km/h; 23 mph) on a bearing of 230T. To keep this course against a tidal stream, she was carrying between 1 and 4 degrees of right rudder.[26]
• Shortly thereafter, the CO realized that the helmsman was having difficulty in managing both the helm and the propulsion control and ordered the helm to be transferred to the lee helm watch station.[27]
• 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 manned. 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.[28]
• 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.[28]
• The conning officer ordered "right standard rudder" to turn to starboard at 05:23 and a second later the after steering position took control.
• 15 seconds later, the main helm position regained control in "backup manual mode".
• At 05:23:24, the throttles were finally matched and the ship started to slow.[28]
• Three seconds later, the aft helmsman took back control of the steering. The report notes that this was the fifth change of control in two minutes.
• At 05:23:44, fifteen degrees of rudder was ordered and John S. McCain finally ceased to turn.
• Fourteen seconds later, at 05:23:58, the collision occurred.[29]

The ship's user interface was found to have contributed to the sailors' confusion.[30]

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.[31] 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.[32]

On June 19, 2019, the National Transportation Safety Board (NTSB) released their report on the accident.[33] 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.