The pilot of a helicopter that crashed on a sightseeing flight off the Hawaiian island of Kauai last month, killing three passengers, told investigators that the aircraft vibrated and spun before plunging into the water, according to report released Friday.
The National Transportation Safety Board’s preliminary report did not identify a suspected cause of the March 26 accident, but said the pilot said he experienced “a high frequency vibration throughout the helicopter that came in waves and became stronger each time.” The cause won’t be identified until the final report comes out likely sometime next year.
The helicopter was carrying the pilot and four passengers when it crashed just off remote Kalalau Beach, on the Na Pali Coast on Kauai’s North Shore, an area that is otherwise reachable only by an 11-mile (18-km) hike or by boat. The area’s tall seaside cliffs and sharp mountain ridges can contribute to turbulent air and quick weather changes that pose hazards for aviation.
The pilot and surviving passenger sustained serious injuries.
According to the report, the pilot said the vibrations began as he made a left turn away from the shoreline as part of the normal flight pattern. The helicopter then began quickly rotating clockwise. He put the aircraft in an autorotation — a maneuver that allows the rotor to spin with the force of air, rather than by the power of the engine — which stopped the spin. He made a mayday call before crashing into the water about 75 yards (69 meters) off the beach.
Former NTSB investigator Alan Diehl said “it sounds like a catastrophic mechanical failure, likely involving the tail rotor.”
The helicopter rolled onto its right side and became partially submerged. The report did not address how the pilot and one passenger survived the crash, nor did it say where the surviving passenger was sitting.
A witness who was flying near the accident site saw the crash and reported that the helicopter appeared to be intact before it struck the water and broke apart, the report said.
Authorities identified the three people killed as Margaret Rimmler, 65, and Patrick Haskell, 59, both of Massachusetts, and Ukrainian national Oksana Pihol, 40.
The helicopter was operated by Airborne Aviation, which does sightseeing tours of Kauai’s canyons, shoreline and waterfalls. Airborne advertises a “doors-off thrill seekers adventure tour” that seats up to four people. Helicopter tours are a popular way to explore the cliffs, beaches and waterfalls lining the Na Pali Coast.
Aviation safety expert Jeff Guzzetti agreed with Diehl that there was some kind of mechanical problem with the helicopter — likely in the tail rotor. That’s what the helicopter’s vibrations and sudden spin point to, though it is too soon to pinpoint what was the specific problem, he said.
“Certainly it seems to lead to a mechanical failure in the helicopter, which would point the investigation to maintenance and design issues,” said Guzzetti, who used to investigate crashes for both the NTSB and Federal Aviation Administration.
Guzzetti said it appears that the pilot did the right things because he was able to stop the spinning, but the helicopter didn’t have enough time or altitude to reach the beach.
Investigators will learn more about what caused the crash as they examine the wreckage and its maintenance history as well as interview everyone involved.
The accident was the latest in a series of fatal crashes that has plagued the industry for decades. At least 16 people have died in helicopter crashes in Hawaii in the past seven years, including two crashes in 2019.
Sightseeing companies in other parts of the country, including New York, have also faced crashes. One last year on the Hudson River in New York that killed the pilot and a family of five Spanish tourists. Five died in 2018 when a charter helicopter offering “open door” flights went down into the East River. And in 2009, a collision between a plane and a tourist helicopter over the Hudson killed nine people.
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Johnson reported from Seattle. Funk reported from Omaha, Nebraska.