U.S. Marine Corps Promises Safety Changes After Deadly AAV Accident

U.S. Navy file image

Published Mar 30, 2021 10:14 PM by The Maritime Executive

The U.S. Marine Corps is promising to improve safety in the wake of the deadly amphibious assault vehicle (AAV) sinking last July, which claimed the lives of nine servicemembers. It was the deadliest training accident involving the vehicle class since it entered service in 1972. 

A command investigation into the casualty was released last week, and it shows a range of failures in maintenance, training and leadership in the months leading up to the casualty.

On July 30, 2020, the 15th Marine Expeditionary Unit was conducting an exercise with the Makin Island Amphibious Ready Group off San Clemente Island, California. A column of AAVs departed the island and got under way for the USS Somerset, intending to return to her well deck after a day of amphibious assault maneuvers. At a position about two miles offshore, the last AAV in the column began taking on water, and the commander attempted to signal for help using flags. No safety boat was on hand, a violation of operating procedures. After about 20 minutes, another AAV spotted the flag and called in the distress situation. 

Meanwhile, the water in the disabled AAV rose to chest level and the bilge pumps began to fail. The commander finally ordered the crew to abandon ship. Before all could get out, a wave swept over the AAV, causing the vessel to capsize with an open hatch. It sank rapidly, leaving five people on the surface and 11 inside.

Three made it back up, including one who died of injuries after rescue; the remaining eight victims were found in and around the AAV at the bottom. According to the command investigation, many were still wearing their body armor and combat gear, including two victims who still had rifles slung over their shoulders.

“The embarked personnel were not trained appropriately and did not realize how dire the situation was,” the command investigation determined. 

The AAV was raised and inspected after the casualty. It had been issued to its crew in poor condition, the report found, and had been selected for issue from a pool of vehicles in need of maintenance. The after-accident report determined that the unit leaked at failed seals on an air vent and at a badly-installed headlight. In addition, its transmission failed under way after leaking out its oil through a faulty drain line. The evacuation lighting system had also been disabled. 

Once in the water, these mechanical faults combined with poor preparation and human error to produce a serious casualty. The crew had not had a safety briefing on emergency egress; chemical light sticks had not been installed to mark hatch handles, forcing the troops to use their cell phones for light; and the commander waited far longer than the standard operating procedure before ordering abandon ship. 

In the wake of the casualty, several senior officers were removed from their posts, including the commander of the unit's battalion and the commanding officer of the 15th MEU. The commander of the AAV - who was among the survivors - may face disciplinary action, according to the report. The Marine Corps is inspecting all of its 800-plus AAVs, and the Government Accountability Office has launched a review of all military tactical vehicle accidents over the span of the last 10 years. 

The Marine Corps will also be reinstating the use of emergency escape breathing systems for AAV crews, beginning temporarily with the use of borrowed Helicopter Aircrew Breathing Devices (HABD), according to Business Insider. The "waterborne egress capability" (WEC) bottles were discontinued in 2015 during the sequestration budget crisis. "It will be a requirement to be trained and equipped with a Waterborne Egress Capability device to be in the back of an AAV or ACV," a Marine Corps official told Business Insider. 

The aging AAV will eventually be replaced by the BAE/Iveco SuperAV, a wheeled alternative which is already in service in Brazil and Italy. The first delivery of 18 units occurred in October 2020, and full-rate production was approved in December.