Dec. 17—Investigators found problems with an anti-skid device after the crash of a Saab 2000 turboprop last year at Unalaska's airport that left one passenger dead and several injured, according to federal documents released this week.
The Ravn Air Group pilots landed with gusting tailwinds on Oct. 17 and lacked the flying time traditionally required for the challenging Aleutians flight, according to a massive fact-finding docket released Wednesday by the National Transportation Safety Board.
A report that's part of the docket describes concerns about Ravn's safety culture at the time.
During landing after a second approach to Unalaska in windy conditions with 39 passengers and three crew, the plane careened off the runway, crashing through a perimeter fence and across a road before coming to rest on rocks at the water's edge, the front wheel in the water of Dutch Harbor. Shrapnel and part of a propeller sliced into the cabin.
A 38-year-old Washington state man coming to Unalaska for work died and four passengers were injured.
His death marked the first crash-related fatality for a U.S. commercial airline in the past decade.
The crash flight was marketed under the PenAir name, short for longtime Alaska carrier Peninsula Airways, which flew the Saab 2000s into Unalaska. But the flight was operated by Ravn Air Group subsidiary Peninsula Aviation Services Inc., which bought PenAir's name and assets including the planes in 2018 after PenAir declared bankruptcy.
Many pilots told investigators morale began to decline in summer 2019 during conversations about reducing qualification minimums for airports like Unalaska, according to the report.
The company's safety director told investigators "he considered the overall safety culture as 'still good' but said that he had pilots approach him saying they were 'not as comfortable anymore... saying something or making a decision and being questioned on it' since the new management came in," the report said.
The docket includes hundreds of pages of reports but does not include a probable-cause finding. A board meeting on the investigation is projected for next year.
The day of the crash, the captain told investigators he decided to go around for a second approach after the plane "got out of position" as he was turning off the engine anti-ice switches. Neither pilot could remember the specific wind reports they were getting at the time, but the captain said it seemed calmer on the second pass.
Winds during the go-around were reported at 8 knots, and then 16 gusting to 30 afterward, investigators have said. During the plane's second approach, winds were reported at 24 knots.
The plane touched down at 126 knots and slowed to an expected 80 knots — but then stopped slowing as usual, the first officer told investigators. The captain applied full brakes and maximum reverse thrust.
"He stated he felt no pulsing or 'chattering' of the brakes, typically felt when the anti-skid system was engaged," the report states. "Both crewmembers reported applying maximum pressure on their brakes shortly after that point."
The first officer said he called for the plane to be steered to the right so it didn't go straight off the runway and into the water, the report says.
A different report on the Saab 2000′s systems and structures described a mechanical issue that could have affected the interplay between the brakes and the plane's anti-skid controls.
The investigation into the plane's anti-skid system on the left side of the plane discovered a problem with crossed wiring, according to the report. Wire harnesses on the left gear wheel speed transducer "were incorrectly installed," the report said. Right gear wire harnesses were installed correctly.
Crossed wires could cause problems with the brakes not releasing on the left side of a plane, according to an analysis provided in the report by Crane, manufacturer of the anti-skid system.
The report does not make clear when the wires were swapped.
The report also references Ravn's push to reduce the qualifications for pilots flying into Unalaska.
PenAir had required a minimum of 300 hours of flying time in the planes, with a 100-hour waiver only for pilots with substantial experience. By summer 2019, pilots told federal investigators, Ravn was pushing to reduce the requirement to 100 hours, remove the requirement entirely provided the pilot had check airman approval, or keep the 300-hour requirement but in right or left seat.
The captain had 131 hours of flying time in the Saab 2000 and was on his 10th flight with PenAir into Unalaska when the crash occurred, according to the report.
The first officer had 138 hours in the Saab 2000 and had flown into Unalaska 15 times before with PenAir, according to the report.
The report quotes a Ravn vice president of operations saying the 300-hour minimum didn't track with airlines in the Lower 48: "I'm not convinced that it's necessary because it's not done elsewhere. There are mountains around the country, around the world. Air is air. Physics are physics. Why is this different?"
Several senior pilots and check airmen voiced concerns about the potential change to reduce qualification requirements, the report states.
"The chief pilot at the time of the accident was asked about concerns pilots had to reducing the company designated airport experience requirement," the document said. "She stated that several pilots voiced concerns, but she didn't ask them why, stating 'I just assumed it was because they thought Dutch Harbor was an airport, a special airport.'"
Ravn declared bankruptcy in April. Smaller airlines scrambled to fill the route gaps left in the wake of the sudden departure of the state's largest airline.
Ravn Alaska reformed this year under entirely new leadership. The company last month announced the start of service to six communities through regularly scheduled public chartered flights offered by Ravn Travel between Anchorage and Unalaska, Sand Point, Homer, Kenai and Valdez.
Representatives of the former company could not be reached for a statement.
A representative of the new Ravn Alaska contacted Wednesday said he could not immediately provide a comment.
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