A deep-water search operation on Tuesday recovered the three-member flight crew and wreckage of a Hawaii Life Flight medical transport plane that crashed into the ocean Dec. 15 off Maui near Kaupo, according to the National Transportation Safety Board.

The Raytheon Aircraft Company (formerly Beech) C90A, twin-engine, turbine-powered airplane’s cockpit voice recorder, cockpit image recorder and other electronic components will be transported to the NTSB laboratory in Washington, D.C., the federal agency said in a statement today to the Honolulu Star-Advertiser.

Pilot Brian Treptow, flight nurse Courtney Parry and flight paramedic Gabriel Camacho were killed when the plane spiraled into the ocean after departing Kahului Airport to pick up a patient at the Waimea-Kohala Airport on Hawaii island.

The NTSB released a preliminary report on the crash Jan. 5 that provided a timeline and other details surrounding the ill-fated flight. The agency indicated today that its investigation into the cause of the accident is expected to be completed in 12 to 24 months.

Guardian Flight, parent company of Hawaii Life Flight, was contracted to undertake the search operation, according to the NTSB statement.

The search vessel, the MV Island Pride, operated by Ocean Infinity, arrived at Oahu Saturday. On board the vessel when the search began Sunday were the NTSB investigator-in-charge, the chief of the NTSB Office of Transportation Disaster Assistance, the Guardian Flight’s director of safety, “and a project manager that has prior experience with over-water loss recoveries,” the NTSB said.

Side-scan and multibeam sonar, unmanned underwater vehicles and a remotely operated vehicle were used to search an area of about 54 square miles at depths ranging from 4,500 to 7,500 feet, according to the statement.

After the vessel’s high-precision acoustic positioning system detected a series of pings from the acoustic beacon on the cockpit voice recorder, the wreckage was located at about 5:30 a.m. Monday at a depth of about 6,420 feet, which was about 1,200 feet south of the last data point received from the airplane, the NTSB said.

After additional surveys by the remotely operated vehicle, “the flight crew and the majority of the wreckage were recovered Tuesday.” The NTSB said the wreckage will be transported to a secure location in Hawaii for further examination.