HA'ENA, Kaua'i — A Heli USA tour helicopter that crashed Friday flew into what surviving passengers described as a "wall of rain" off the rugged cliffs of north Kaua'i before it crashed into the sea, killing three.

Survivors told federal investigators that the helicopter hit the ocean, tipped over and was full of water in seconds. The pilot and two passengers swam out of the swamped, upside-down aircraft and survived. One of those passengers was a nonswimmer.

National Transportation Safety Board investigator Nicole Charnon, who conducted interviews with the survivors, said the survivors had been sitting in the Aerospatiale AS350's front left, rear left and rear right seats.

Two other passengers' bodies were found in the water and recovered by a Navy helicopter, but they could not be revived.

Kaua'i Fire Chief Robert Westerman said that county water safety officer Kaeo Lopez and firefighter Gavin Kennelly followed a fuel slick and debris upwind to locate the wreck Friday and dove to recover the body of the remaining passenger. The helicopter lay in 20 to 25 feet of water. They found the victim still strapped in by the aircraft seat belt.

All the passengers had been wearing life vests around their waists, but not all of them had managed to properly fit them around their necks after the crash, Charnon said.

The wreckage of the helicopter was removed from the waters off Ha'ena yesterday and delivered to a hangar at Lihu'e Airport, where National Transportation Safety Board investigators will study it.

The identities of the victims have not been released because police said they have not completed notification of the families of the crash victims. Two survivors, a husband and wife from Wisconsin, were to fly home yesterday.

NTSB senior safety inspector Debra Eckrote arrived on Kaua'i yesterday to oversee the investigation of the crash. She said the pilot, who also remains unidentified, is a former Houston police helicopter pilot who has also flown helicopters for electronic news-gathering agencies. She said he had been flying tours for Heli USA on Kaua'i for between six and seven weeks.

Charnon said her interviews with the surviving passengers indicated the aircraft had been flying uneventfully when the passengers saw what they described as a "wall of rain."

"The helicopter flew in there. They couldn't see. And suddenly they were near water," she said.

Charnon said the pilot reported that on entering the system he maintained visual contact with the shore and was attempting to turn the helicopter to fly back out of the storm when he experienced "a rapid sink rate." Eckrote said the pilot also reported reduced rotor speed before his aircraft hit the ocean.

Residents have described the sudden thunderstorm that appeared over Kaua'i's north shore valleys as intense, with heavy rain and flash flooding, thunder, lightning and strong wind. Charnon's interviews yielded almost identical descriptions of weather conditions from the crash survivors.

They recall "thunder and lightning, and torrential rainpours" following the crash, she said.

Eckrote said an NTSB weather expert will investigate the weather phenomenon at the time of the crash. She said she has not concluded whether the weather was the cause or a significant factor in the crash, but she said the pilot reported he had been flying the copter all that day without indication of mechanical difficulties.

"Everything is suspect right now," she said.

Her team will be joined by representatives of the aircraft builder and its engine manufacturer in studying the wreckage. Eckrote said the study will be made more difficult by the condition of the wreck, which broke up into several pieces after two days of rolling in waves on the ocean floor.

"Being in the ocean moving around for two days doesn't help. Being in salt water ... could hinder some of our testing," Eckrote said.

Divers yesterday strapped pieces of the wreckage together, and the parts were carried out in clusters by a UH-1 Huey helicopter owned by Pacific Helicopters of Maui. The parts were flown from Ha'ena to the Hanalei town soccer field and loaded onto a flatbed truck for transfer to Lihu'e Airport.

Heli USA vice president John Power thanked personnel who participated in the rescue. He said the company is working with the families of the crash victims as well as with its own staff, to ease the impact of the crash.

"We fly over 120,000 passengers a year. This was very, very unfortunate," Power said.

The company stopped tour operations on Kaua'i Saturday out of respect for the victims, he said. The firm resumed flying tours yesterday.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.