The two-seat OH-58D Kiowa Warrior went down Wednesday afternoon. The names of the soldiers killed were not released pending family notification.
Col. Matthew Margotta, commander of U.S. Army Garrison Hawaii, said the Army was technically calling the accident a "hard landing" because the pilots were in control of the aircraft when it went down.
"Our thoughts and our prayers go out to the family members," Margotta told reporters.
Honolulu Fire Department Capt. Earle Kealoha said firefighters responded to a call of a downed aircraft at 3:34 p.m. But when they arrived four minutes later, federal fire crews already had the fire under control.
The Army said it was investigating the accident.
The helicopter belongs to the 25th Combat Aviation Brigade, part of the 25th Infantry Division. The brigade is preparing for a 12-month deployment to Iraq scheduled to begin October.
Kiowa Warrior helicopters are used primarily for observation and scouting missions. They can be armed with missiles and machine guns, and are typically flown close to the ground at speeds topping 100 mph.
