Record Breaking Deep Ocean Salvage Operations

In March of 2021, Phoenix International Holdings, Inc. (Phoenix) was tasked by the U.S. Navy to recover a downed MH-60S Seahawk helicopter in the Pacific, near Okinawa, Japan. This recovery involved two key systems associated with the Navy’s deep ocean salvage program: the CURV 21 ROV and the 60-kip Fly Away Deep Ocean Salvage System (FADOSS). These systems, as well as power generators, control vans, hydraulic power units, launch and recovery systems and all required rigging, were transported to Guam and mobilized aboard a regionally chartered vessel, the Multi-Purpose Offshore Vessel Grand Canyon II. This ship is a dynamically positioned, 419 ft long multi-role construction support vessel with a 250-ton crane and plenty of open deck area.Setting the stage for this record breaking recovery was the effort associated with searching for the downed aircraft. This occurred in March of 2020 when Phoenix, working with SUPSALV, used the U.S. Navy’s 20,000 fsw rated Autonomous Underwater Vehicle “Trondheim” to locate the wreckage at a depth of over 19,000 feet.One year later, during the recovery, Phoenix used the U.S. Navy’s 20,000 fsw rated CURV 21 ROV to inspect the wreckage and attach rigging to the aircraft. Next, a 22,000 ft long, 2-inch diameter Kevlar recovery line was lowered to the seabed and the ROV was used to connect the recovery line to the wreckage. The U.S. Navy’s FADOSS was then used to pull up on the Kevlar line, hoisting the MH-60 helicopter from the seafloor to the surface. After nearly 4 hours, the wreckage reached the surface and was lifted out of the water using Grand Canyon II’s 250 ton rated crane. With the wreckage safely secured to the ship’s back deck, the vessel transited to Yokosuka, Japan and the aircraft was offloaded and handed over to the crash investigation team. The depth of this recovery was 19,075 feet. This record breaking recovery depth equates to just over 3.6 miles beneath the sea and is 266 feet deeper than the previous salvage record, also set by Phoenix and SUPSALV during an aircraft recovery operation in 2019.This paper addresses all aspects of this successful record breaking deep ocean recovery, including the mobilization of personnel and equipment to Guam and the at-sea operations aboard Grand Canyon II. Top among the challenges associated with this project were operating at such a deep depth and overcoming the logistical obstacles associated with mobilizing personnel and equipment to the other side of the world. The employees at Phoenix are proud of the role they played in accomplishing this record breaking recovery, soon to be listed in the Guinness Records as the deepest salvage ever completed.