Maintenance failures and human error led to fatal 2020 USMC AAV mishap, investigations find

A combination of maintenance failures and human error led to the fatal assault amphibious vehicle (AAV) mishap on 30 July 2020 that caused the deaths of eight marines and one sailor, according to the findings of separate investigations by the US Navy (USN) and US Marine Corps (USMC) released on 6 October.

The USN 3^rd Fleet conducted the service's investigation, which examined the navy's role in the incident and revealed gaps in the USN and the USMC doctrine and procedures.

The investigation led to Wet Well Manual updates to clarify safety boat requirements, ship requirements to ensure positive control of AAVs during evolutions, as well as additional improvements to the integration of training between sailors and marines. Additionally, all navy commanding officers will attend the Senior Amphibious Warfare Course before taking command. Future AAV operations will require a comprehensive and integrated communications plan to be submitted before AAV operations can occur.

The USMC previously concluded two investigations – a 1 October 2020 safety investigation and a 25 February 2021 command investigation – that prompted 23 institutional actions by the service to ensure the safe execution of AAV waterborne operations.

Equipment changes include a combination of equipment improvements and additional inspections such as procurement and sustainment of a Waterborne Egress Capability programme, electronic tablets for crew members to manage associated technical and procedural manuals, and new criteria for hull watertight integrity, bilge pump function, communications systems, and emergency egress lighting systems.

The USMC also reviewed its publications and policies for operating procedures, technical manuals, and safety structure requirements during training. The service initiated updates to training and qualification prerequisites, authority and decision-making procedures, and safety boat requirements.