CHAMBERLAIN, S.D. (KELO) — In about 30 seconds, a plane carrying 12 people left the runway in Chamberlain, South Dakota, and crashed in a cornfield three-fourths of a mile away, killing nine and seriously injuring three.
Only one second after the plane lifted off the runway did the flight tragically begin to go wrong. According to an onboard lightweight data recorder, two warnings went off in the cockpit warning of a stall. The first was an alarm and the second was a violent vibration of the yoke.
These two actions warn the pilot about an aerodynamic problem. Basically, the plane’s angle wasn’t producing enough lift for the plane to fly.
While all of this is happening, the plane is banking left and right. At its peak, the plane reaches 460 feet in the air, nearly the height of Mount Rushmore.
Less than 15 seconds after the first two warnings, an automated system called the stick pusher attempted to recover the plane’s stall. It didn’t work.
The plane crashed about 15 seconds later.
What happened? Clues point to ice concerns
What happened? That’s the question many have after an airplane crash. This week, the National Transportation Safety Board released its preliminary report about the crash.
In it, there was no cause, but a lot of clues. John Goglia is a former presidentially appointed board member of the NTSB.
“When you look at these reports, the initial data from the accident, you have to remember that it’s initial and subject to change,” Goglia said.
The NTSB is an independent agency that investigates every American plane crash, other major transportation accidents and helps with international plane crashes. The agency is led by a five-person board. Goglia served from 1995 to 2004.
“We have a set of procedures that we follow, that everyone has to follow, and it has served us well over all these years. So, if you just stick to the facts, stick to the process, the outcome is quite robust,” Goglia said.
Goglia didn’t just lead a government agency. Before being appointed, he was a mechanic. He is the only board member to ever have a Federal Aviation Administration aircraft mechanic’s certificate and now is an aviation safety consultant.
He went through the preliminary report with KELOLAND News this week.
“Just an initial brush of this, it certainly looks like weather played a significant role,” Goglia said.
At the time of the crash, the area was under a Winter Storm Warning and the interstate was closed from Chamberlain to Wyoming.
“As an investigator, one of the things that jump out is the weather conditions at the time,” Goglia said. “They weren’t flying in the best of conditions. From a personal opinion side, it sounds like they really wanted to get going, which can be a bad thing.”
Four generations of one family died in the crash. The Idaho Falls family was in central South Dakota for an annual hunting trip the day after Thanksgiving.
Those killed were Jim Hansen Sr.; his sons, Jim Jr. and Kirk Hansen; Kirk Hansen’s children Stockton and Logan; Kirk Hansen’s sons-in-law, Kyle Naylor and Tyson Dennert; and Jim Hansen Jr.’s son Jake and grandson Houston were killed.
Kirk’s son Josh, Jim Jr.’s son Matt and Jim Jr.’s son-in-law, Thomas Long, survived.
The family arrived in South Dakota shortly after 9:30 a.m. on Black Friday. The pilot purchased 150 gallons of fuel at an automated fuel pump at the airport and the plane was parked outside through the rest of the day and overnight.
During that time, freezing rain and snow was reported near Chamberlain’s airport.
Goglia’s concern: ice.
If you have flown a commercial jet out of South Dakota, you’ve likely experienced de-icing.
Getting rid of ice on the ground is vital to a plane’s ability to fly. According to the International Civil Aviation Organization, the plane is designed to fly “clean.”
“Any deposit of ice, snow or frost on the external surfaces of an aeroplane, except as permitted in the flight manual, may drastically affect its performance,” the United Nations’ run organization wrote in a 68-page manual for de-icing.
Planes are built with ice protection, but that is only designed for in-flight use, not for sitting on the ground.
Ice brings two issues: aerodynamics and weight.
Weighing down the plane
“What a lot of people don’t realize, ice is heavy,” Goglia said. “Water weighs about eight pounds per gallon and you can put an awful lot of water on these airplanes with freezing rain.”
A plane has a certain maximum weight it can handle. According to the flight manual for the PC-12/47E, this plane could handle 10,450 lbs at take-off. To give some perspective, the plane with no people, no baggage, no hunting gear and even no fuel weighs 6,173 lbs. This gives about 4,277 lbs to use for everything else.
Goglia said that will be one area where investigators will look.
Messing with the aerodynamics
The other is aerodynamics.
“Ice will affect the aerodynamics of the airplane,” Goglia said. “So, you could take off the ground with contaminated wings, but you usually don’t get too high.”
The ICAO manual explains that ice on a wing messes with the very principals of flying.
“A wing has a critical angle of attack when the lift starts to decrease and the aeroplane is said to stall. Before the critical angle of attack, as angle of attack increases, more lift is produced. This is needed during take-off. When the wing is contaminated by small amounts of frost, the critical angle of attack is decreased and the airfoil may stall even before a stall warning,” according to the ICAO manual.
Only one second after take-off was the first stall warning.
“The airplane has got to be clean,” Goglia said.
In Goglia’s current role, he works on safety with small operators.
“I’ve had them all put into their books: ‘Clean airplane,’ not just clean wings,” he said. “Clean airplane. All snow and ice has to be removed.”
Did this plane have all the snow and ice removed? It’s not clear. According to witnesses, the pilot and another relative spent three hours clearing off the plane before the ill-fated flight.
“I don’t know that they deiced the tail,” Goglia said. “That’s another problem because this has a very high tail.”
He thinks investigators will want to know if there was equipment to help reach, clean and inspect the tail.
What investigators do know from that data recorder found by the NTSB is that the plane made sharp rolls three times. First slightly to the left, then slightly to the right and finally a 64-degree roll to the left.
“Given that fact that he was struggling for control left or right with this airplane, makes me think that he had contaminated flight controls,” Goglia said.
NTSB investigators will need to go through mountains of evidence, but for this safety expert with more than 40 years of experience, ice impacting control of the plane is a possibility.
“I tend to think that may have been part of the problem, shooting from the hip, but the investigators will go over everything in the physical evidence at the field,” he said.
Like a jigsaw puzzle: how the NTSB solves plane crashes
Most of what the NTSB does is behind closed doors. Goglia and former lead NTSB investigator Greg Feith are shining a light into the process in their new podcast Flight Safety Detectives.
In a recent episode, the two give listeners an inside look at the investigative process.
The complex investigative process usually takes more than a year to complete. Right now there are six deadly crashes in South Dakota that are still being investigated.
“The investigation is like a jigsaw puzzle,” Goglia said. “You take all these points of information and put them together and even if you have a piece missing, you can still tell the picture.”
Goglia walked KELOLAND News through some of the steps that investigators will likely take to figure out the puzzle.
“I assume that the airplane is sequestered in someplace,” he said.
Investigators will look at the physical evidence.
“They will look at the condition of the engine,” Goglia said. “Was it making power at the time of impact? You can tell some of those things by damage to the propeller.”
They will call on NTSB weather experts in Washington, D.C., to analyze the weather conditions further. Pilatus Aircraft Ltd will provide information on their plane. The NTSB will also be working with the Swiss Transportation Safety Board since the aircraft manufacturer is based there.
Goglia isn’t as concerned about the airplane.
“The PC-12 is a great airplane, I’ve actually flown in it,” he said.
The flight data recorder will provide key information to investigators, but what Goglia is really looking at is hearing the pilot’s voice.
“Especially if the pilot had a conversation or sometimes pilots have a conversation with themselves and give clues when you have a recorder. They just talk about what’s going on,” Goglia said.
The NTSB said the recorder did capture the cockpit sound.
“The NTSB will convene a group of technical experts to produce a transcript,” the agency said in a statement.
Finally, the three survivors could bring a lot of information to investigators.
“Because they can tell what on-board the pilots were saying or doing,” Goglia said. “Keep in mind, though, after a very traumatic event sometimes our memories are not what they were or what they could be.”
Since 1967, the NTSB has been perfecting what to look for to find the probable cause of an air disaster.
“They’ll just go down the checklist,” Goglia said. “One item after another, after another and if need to, they’ll go back and physically look at the airplane to see what kind of condition it was in.”
Then, in 12 to 14 months, the agency will issue a report with a probable cause.
“They don’t go beyond that normally unless there’s a safety item that they’ve identified that they want to get out to the industry,” Goglia said.
KELOLAND News Investigates is looking into the rules related to removing ice and what equipment exists in Chamberlain. Watch for that story later on KELOLAND News.