LIHUE, Hawaii – The pilot of a tour helicopter that crashed, killing three people including two Mainers, told federal investigators he was trying to avoid another chopper when his helicopter encountered a thunderstorm and plunged into the ocean.

But the account Heli USA pilot Glen Lampton gave to the National Transportation Safety Board was disputed by his fellow survivors and Ken D’Attilio, owner of Inter-island Helicopters, which owns the other chopper, a McDonnell Douglas 500.

Lampton reported taking evasive action by veering to the left to avoid the MD 500, and entering a region of heavy rain, said Debra Eckrote, lead investigator for the NTSB.

His helicopter then lost altitude and crashed, killing Laverne Clifton, 68, of Beloit, Wis., and best friends Mary H. Soucy, 62, and Catherine Baron, 67, of Portland, Maine. The other two survivors – Clifton’s daughter Karen, 44, and her husband Bill Thorson, 48 – said they didn’t believe Lampton had to maneuver to avoid hitting the other helicopter.

“There was a helicopter below us. He was turning around but he was nowhere near us. Our helicopter pilot said the storm was coming and we would probably have to turn around. We never had to dodge another helicopter,” Karen Thorson said from Wisconsin.

Bill Thorson said they had spotted dark storm clouds ahead.

“At the time, I looked down and there was a small helicopter a long way down. It looked like a bird,” he said. “It was going the other way, and at that time the pilot told us we may have to turn around, too, and we flew into the storm.

“We couldn’t see anything in front of us. We dropped down and we almost hit the water at that time and he tried to pull us back out and then we slammed into the ocean,” Bill Thorson said.

Lampton, who has piloted helicopters for about 16 years, has worked for Heli USA for six or seven weeks, the NTSB said. The former Houston police helicopter pilot has also flown for news agencies, it said.

D’Attilio said his pilot, Ian Bogano, was nowhere near the Heli USA chopper when it crashed.

D’Attilio blamed the accident on Lampton’s lack of experience in flying helicopters around Kauai.

Heli USA Vice President John Power said he couldn’t comment on the events leading to the crash, since it is part of a federal investigation.

A preliminary assessment of the wreckage of the Aerospatiale AS350 found it was functioning properly when it hit the water.

“There is no evidence of mechanical failure or malfunction. There is no evidence of a loss of power,” Eckrote said.