first published on August 9, 2018 by Josh
On December 9, 1999, 18 United States Marines were being ferried between the amphibious assault ship Bonhomme Richard to the USNS Pecos to conduct an operation in preparation for their upcoming deployment on the 15th Marine Expeditionary Unit. The weather was fantastic, and the seas were smooth, but a freak accident caused the helicopter’s landing gear to become entangled with safety netting near the helicopter landing area which then flipped the aircraft over into the water. Eleven Marines were rescued from the water, but six Marines and one Sailor were killed in the incident.
Here is the footage from that incident.
This training accident sparked a new requirement in the Marine Corps. Any Marine or Sailor who will be required to fly via rotary wing aircraft over water now must complete a safety egress training course called the Helicopter Dunker, or Helo Dunker for short. This underwater egress training (UET) gives Marines and Sailors the skills and tools that they need to escape from an aircraft should it ever need to ditch over water.
The course lasts for several days of training, but can be compressed into a single day in order to fit the needs of the unit conducting the training. During the course, Marines and Sailors learn how to use handheld air-tanks that give them up to 8 minutes of oxygen underwater. They are taught the basic fundamentals of breathing through this tank in a series of short instructional classes, and given an entire day of practical application that is conducted inside of a pool.
When the Marines are prepared, they are put into a mock helicopter hull, and then dunked into the pool. As the hull submerges in the water, it slowly rotates over and becomes inverted. While blindfolded, and without the aid of the safety divers, Marines are required to exit the hull through the appropriate emergency exits blindfolded both with, and without access to the air tanks. A number of different scenarios are ran, some of which involve Marines and Sailors using the closest exit to their seat, other where Marines and Sailors are all forced to wait in a queue underwater and upside down so that everyone can use the “available” exits.
Here is footage of Marines completing the underwater egress training course.