Four people were killed when a contractor’s helicopter crashed on the Hawaiian island of Kauai, the US Navy said on Tuesday.
The Pacific Missile Range Facility said the aircraft crashed on the north side of the installation shortly after 10am. It was flying in support of a training operation.
The National Transportation Safety Board said it was investigating the crash of the Sikorsky S-61N.
The S-61N is among the helicopters built between 1959 and 1980 by Sikorsky Aircraft, which is now part of Lockheed Martin. It was designed to carry a substantial freight or passenger payload.
The helicopters were optimised for use over water, for example to support oil rig operations. Versions were also used by all branches of the US military. Licensees in the UK and other countries have also built the aircraft.
A Kauai County representative said county police and firefighters responded and were assisting the military. Kauai police were helping the navy with security and investigation support, Coco Zickos said.
An investigation will begin to determine the cause of the accident, the range facility statement said.
The Pacific Missile Range Facility is a navy base on the western edge of Kauai where the military tests missile defences and units conduct exercises.