LIHU'E, Kaua'i — A preliminary National Transportation Safety Board report released yesterday on a fatal tour helicopter crash Sept. 23 off Ha'ena said none of the other pilots in the area that day experienced the turbulence and downdrafts reported by the pilot of the downed Heli USA Airways chopper.

The pilot, Glen Lampton, 43, and a Wisconsin couple survived the crash, which killed three other passengers.

The NTSB report said other pilots reported limited visibility because of rain near Ka'ilio Point, but they were able to descend to between 100 and 300 feet above ground to get out of the rain. The pilot of a Hughes MD500 tour helicopter said he turned around in the rainstorm and had dropped to 100 feet above ground when he managed to break out into clearer skies.

In one of the key mysteries of the Heli USA crash, Lampton reported to NTSB investigators that he "suddenly saw a MD500 coming straight for me" as he approached Ka'ilio Point, but that his own elevation was 2,000 feet. The Wisconsin passengers, Karen and Bill Thorson Jr., said they saw a helicopter believed to be the MD500, but that it was far below them.

The NTSB preliminary report did not shed any light on the discrepancy in the accounts.

The report said Lampton reported that the helicopter lost altitude in the rainstorm, hit the ocean, then lifted and began spinning before hitting the water again. Other pilots said they heard his mayday calls and remarks on the radio that he was experiencing wind shear, a drastic change in wind speed or direction over a relatively short distance.

Lampton told the NTSB that the aircraft remained upright briefly, then rolled over and sank. Survivors reported having to swim up out of the sinking wreckage.

All six aboard the tour helicopter survived the impact with the ocean, and Lampton and the Thorsons made it to shore. Karen Thorson's father, Laverne Clifton, 68, died in the water as a result of heart failure from near-drowning. Also killed were Mary Soucy, 62, and Catherine Baron, 68, both of Portland, Maine. Autopsies determined the women drowned.

A final report detailing the probable cause of the helicopter crash is not anticipated for at least a year.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.