Investigators probing role weather may have played in deadly South Dakota plane crash

John Roach
An NTSB investigator examines the wreckage of a Pilatus PC-12 airplane at Chamberlain Municipal Airport in South Dakota
An NTSB investigator examines the wreckage of a Pilatus PC-12 airplane near Chamberlain Municipal Airport in South Dakota. The aircraft crashed on Saturday, November 30, 2019, moments after taking off amid heavy snowfall. The crash killed nine of the 12 people on board. (NTSB)

The National Transportation Safety Board (NTSB) released new information Tuesday about the plane crash in Chamberlain, South Dakota, that killed nine people and injured three others within a mile of takeoff. A review of the available information about the fatal crash, which occurred Saturday within a mile of takeoff, indicates weather was a significant, if not major, factor, experts say.

Chamberlain, and much of South Dakota, was under a winter storm warning and experiencing near-blizzard conditions around the time of the crash on Saturday.

The single-engine Pilatus PC-12 arrived in Chamberlain Friday at about 9:30 a.m. CST, according to the NTSB report. The airplane remained parked on the airport ramp until the accident a day later, the report noted.

"They landed on Friday ahead of the storm, and it looks like they just left the plane parked on the runway," said AccuWeather senior meteorologist David Samuhel, who reviewed the NTSB statement. "There was probably 8 or 9 inches of snow, so the plane probably had a whole lot of snow and ice on it." The NTSB is still investigating the crash, and it's not clear if the snow and ice were cleared from the aircraft before takeoff. Samuhel said, "If they didn't get the snow and ice off the wings, that would be a huge problem."

A photo of a Pilatus PC-12 in flight. (Pilatus Aircraft Ltd)

An aviation expert AccuWeather spoke with also said there was likely frost or ice below the layer of snow and added that it's "doubtful the facilities exist for that sort of deicing at this small airport." AccuWeather reached out to the Chamberlain airport manager, who as of late Thursday had not yet responded.

Ice and snow needs to be properly removed from a plane for the flight to be legal, and if that doesn't happen, the consequences can be dire. "You're looking at [an] increase in drag of 40 percent and decrease of lift of 30 percent if you don't deice properly."

Also, the NTSB reported the weather observation station at the Chamberlain airport recorded winds of 7 mph, with half-mile visibility and moderate snow and icing. AccuWeather's Samuhel believes the winds were likely much stronger.

"I question the wind reading at Chamberlain airport," he said. "Pierre is about 65 miles to the northwest of Chamberlain, but the conditions probably weren't much different and winds in Pierre were gusting to 40 mph and even higher some parts of the day.

"They were leaving Saturday and the storm was starting to wrap up, but they were still in a bad part of it where the wind was really kicking up and they were probably getting blowing snow, too," Samuhel said.

According to Travis Garza, president of wellness company Kyani, the company's two founders, Jim Hansen and Kirk Hansen, were among the crash victims. The other seven passengers who died were their relatives; three passengers survived.

Another factor that could have contributed to the crash was a possible load imbalance. The Pilatus PC-12 pilot's information manual notes the "maximum number of occupants is 9 passengers" plus 1-2 pilot(s). According to the NTSB report, there were 12 people on the plane.

There were 393 U.S. civil aviation deaths in 2018, an increase from 347 in 2017, according to the NTSB. Most aviation deaths in 2018 took place during general aviation operations - all civilian flying except scheduled passenger airline service - when 381 were killed, compared to 331 in 2017.