Officials at Wheeler Army Airfield near Honolulu reported losing communications around 10 p.m. Tuesday with the crew of a UH-60 Black Hawk, the Coast Guard said in a news release.
Responding teams reported spotting a debris field about 2 miles (3 kilometers) west of Kaena Point, Oahu, shortly before 11:30 p.m., the release said.
An airplane, two helicopters and several boats are being used in the search across an area with light winds and 2-foot seas.
Two Black Hawk crews were conducting training between Kaena Point and Oahu’s Dillingham Airfield at the time communications were lost, officials said.
Night training offshore is routine, said Lt. Col. Curtis Kellogg, public affairs officer for the Army’s 25th Infantry Division.
The search began immediately after one aircrew lost visual and video contact with the other helicopter, Kellogg said.
The two helicopters are elements of the 25th Combat Aviation Brigade.
The UH-60 Black Hawk is a four-bladed, twin-engine utility helicopter manufactured for the Army by Sikorsky Aircraft starting in the 1970s.
Kaena Point is northwest of Honolulu.