"We just believe that helicopter tours should be flown with doors closed", Sweet said. They drowned after the helicopter rolled over and sank.
While the pilot emerged from the cockpit when the helicopter flipped in the water after the apparent failure of a floatation bag on the skids, all five passengers were trapped inside the cabin and had to be cut free by divers. NTSB investigators have interviewed the pilot, but the agency didn't release any information about what he said.
The Federal Aviation Administration on Friday banned "open-door" helicopter flights where passengers are strapped into hard-to-undo harnesses - after one such flight crashed into the East River on Sunday, killing five. "Our passenger restraints can be released quickly in an emergency".
Only the pilot, who was wearing a regular seatbelt, escaped and survived.
Staff members from Jack Harter Helicopters, which operates the only doors-off helicopter tour on Kauai, said the company is continuing to offer the tours because their harnesses aren't the same kind utilized by Liberty Helicopter and can be quickly released in an emergency.
The National Transportation Safety Board is now investigating the cause of the accident.
The government standards governing their operations can be less stringent than for traditional tour flights, according to a person familiar with the practice.
The helicopter association's Sweet declined to comment on what may have caused the helicopter to apparently lose power. On Friday, the agency said they found no signs of engine failure or pre-impact mechanical problems. "This includes using FAA-approved seatbelts with quick releases on our flights as well as conducting specific passenger safety training prior to each flight".