The pilot of a single-engine mail plane that crashed last week south of Utqiagvik told federal investigators he heard the autopilot go off and then the plane's control column pitched forward and he couldn't pull it back.
The Cessna 208B Caravan operated by Hageland Aviation crashed on frozen tundra about 2 miles north of the Atqasuk village runway just after 8:15 a.m. April 11. Hageland is one of three carriers under the Ravn brand.
The National Transportation Safety Board is taking the pilot's highly unusual account very seriously, said Clint Johnson, the board's Alaska region chief.
"This one is unique, no doubt," Johnson said.
An investigator will take a seven-member team to Utqiagvik on Wednesday morning to find out what happened — a large response for a nonfatal crash.
That's because the aircraft involved is fast becoming the main workhorse of the Bush air fleet, replacing aging Cessna 206 and 207s, Johnson said in an interview Tuesday. Investigators want to know if there's a problem with the plane's autopilot or other systems.
"We're hitting this with everything we've got initially because there's a lot of these airplanes out there," he said.
The pilot received minor injuries in the crash, according to a National Transportation Safety Board preliminary accident report released Tuesday. The plane was substantially damaged.
[How to tow an airplane: Watch as this helicopter flies away with a wrecked Cessna]
The flight left the Utqiagvik Airport around 8 a.m. for Atqasuk, about 58 miles south, with about 1,500 pounds of U.S. mail, according to the report. The ground below was snowy "remote, flat, featureless, tundra-covered terrain."
The pilot told Johnson the day after the crash that he climbed to 2,500 feet amid clear skies, 9 miles of visibility and a light wind, the report states. With the autopilot on, he began to descend toward the airstrip but saw a band of low fog around Atqasuk when he reached about 1,500 feet, a typical weather phenomenon for North Slope aviators.
The pilot hoped the airport was out of the fog, Johnson said. "But that's when this whole event started, according to the pilot."
He told Johnson that he heard a tone indicating the autopilot was disengaged, the report states. That was "immediately followed by the pilot's control column pitching forward. The pilot said that he was unable to pull the control column back."
The plane descended through the fog, which extended to the ground, then hit the snow-covered tundra and nosed over, according to Johnson and the report he filed. The plane's wings, fuselage and tail assembly were substantially damaged.
The nature of the pilot's injuries weren't immediately clear.
A Ravn Connect spokesman didn't immediately return a request for more information about the crash investigation or the pilot's status Tuesday.
The airplane was equipped with a digital, 406 MHz ELT that instantly transmits a distress signal to search-and-rescue satellites, but search personnel didn't receive any emergency transmitter locator signal, according to the report. Instead, the pilot called Hageland on his cellphone.
A North Slope Borough Search and Rescue helicopter pilot told the NTSB investigator that he flew into ice fog, reduced visibility and flat light that made it heard to make out the terrain, the investigator wrote. Both pilots noticed ice starting to build on the helicopter's windscreen, so they aborted the search and turned back.
A search team from Atqasuk reached the accident site on snowmachines and transported the pilot to Atqasuk, the report states.
The borough on the day of the crash reported that the SAR helicopter picked up the pilot.
The NTSB team headed to Utqiagvik will pull avionics from the plane, including a ground-proximity warning system and autopilot modules, according to Johnson.
He called the pilot's account the first of its kind he's heard.
"We've had autopilot issues but (not) to the point where it overrides the pilot's ability to pull the control column back," Johnson said.