The National Transportation Safety Board has released its final accident report in the November 2019 Pilatus PC-12 crash that killed the pilot and eight passengers, and seriously injured three other passengers. The federal agency concluded that wintry weather, along with a list of poor decisions before and during the flight, contributed to the deadly loss.
Events leading up to the 2019 South Dakota PC-12 fatal plane crash
On the morning of Nov. 29, 2019, the pilot and passengers arrived at the Chamberlain Municipal Airport (9V9) in Chamberlain, South Dakota in a Pilatus PC-12. The aircraft stayed parked overnight on the ramp until its 12:30 p.m. departure bound for Idaho Falls, Idaho (IDA) on Nov. 30.
The morning of the plane crash, all but one of the passengers went hunting. The pilot and other passenger went to check on the aircraft amidst a snowstorm. A representative of the local lodge took the pilot and passenger to the local hardware store where they purchased isopropyl alcohol. They used a seven-foot-tall ladder, which didn’t reach the plane’s tail, and worked for three hours to remove the accumulated snow and ice.
The pilot told the local lodge representative that they needed to get home, the airplane was 98% clear of ice, and the rest of the ice would dissipate during takeoff. The lodge representative said it was snowing hard during their time of takeoff, which is evidenced in the video below showing the aircraft’s takeoff from runway 31 and its immediate left turn.
This aircraft was operated under Part 91 and the owner of the aircraft was the sole pilot. The pilot held a private pilot certificate with an instrument rating and single and multi-engine ratings. The Pilatus PC-12 is a single-engine turboprop aircraft approved for single-pilot operations. The pilot had 2,314 total hours and 1,274 hours in the PC-12.
The loading of the aircraft
The aircraft was configured with two crew seats and eight passenger seats. There were 12 people on board at the time of the accident and none of them were less than 2 years old to be considered lap children. The overloading of passengers is among many factors found to have contributed to the crash.
An estimated weight and balance calculation was performed and showed the aircraft would have been 107 pounds over its approved maximum gross weight. In addition, the center of gravity calculations indicated the aircraft was loaded 3.99 inches to 5.49 inches beyond its aft CG limited.
The weather conditions at the time of the crash
The weather at the time of the accident indicated low instrument flight rules (LIFR). Moderate snow was observed at 12:35 p.m., 3 minutes after the crash. The lowest ceiling was 500 feet overcast and the visibility was .5 miles.
Airman Meteorological Information (AIRMET) advisories existed for moderated turbulence, moderate icing conditions, and IFR conditions due to precipitation, mist, fog and blowing snow. The pilot received a preflight weather briefing at 12:04 p.m., but he did not request current AIRMET information in the briefing.
The airport manager reported having plowed 2 inches of snow in the past 24 to 36 hours and that the weather was deteriorating at the time of the accident.
The photos of the aircraft on the ramp prior to beginning taxi revealed snow had accumulated on the upper surface of the horizontal stabilizer and on the vertical stabilizer. There were icicles present on the horizontal stabilizer bullet fairing.
Photo credit: NTSB report.
What happened after rotation?
According to the flight data recorder equipped on the aircraft, the aircraft lifted off and immediately entered a left turn as seen in the above video. The aircraft reached the highest altitude of the flight of 380 feet above the ground while in a 64-degree left bank before it entered a constant descent until its point of impact with the ground. Throughout the aircraft’s struggle to climb, the airspeed varied between 89 and 97 knots before rapidly declining to 80 knots. The specified rotation speed at maximum gross weight in icing conditions was 92 knots according to the airplane flight manual.
One second after liftoff, the stall warning and stick shaker activated. The stick pusher was activated 15 seconds after liftoff to prevent the aircraft from aerodynamically stalling. A witness described hearing the aircraft takeoff and enter a left turn until he heard the engine noise stop.
Photo credit: NTSB report.
The wreckage covered an 85-foot-long debris path in a dormant cornfield about 3/4 miles west of the airport. The engine and left wing were separated from the fuselage. Post-accident airframe examinations revealed no preimpact failures or malfunctions and the engine was operating within its normal range.
Pilot analysis of the 2019 Pilatus PC-12 deadly crash in South Dakota
The report concluded that the defining event was a loss of control in flight. Factors contributing to this included the pilot’s abrupt and heavy pull rotation technique, an extreme aft center of gravity, heavy aircraft weight, and a 4-knot, too-early rotation. These factors caused a high angle of attack after rotation, which triggered the stick shaker and pusher indicating that the aircraft had entered a stall.
In a simulation performed by the NTSB, in an FAA-approved PC-12 Level D Simulator, the pilot participants found the takeoff to be easier to control using a rotation of lesser pitch rates and angles than the accident pilot used.
As James Reason’s Swiss Cheese Model of safety incidents suggests, there were many holes in the accident chain that lead to the loss of control in flight. The pilot demonstrated four of the five hazardous attitudes of antiauthority that are defined by the FAA, impulsivity, invulnerability, macho and resignation
By blatantly loading the aircraft with two additional passengers, the pilot risked an overloaded aircraft and an aft center of gravity. An aft center of gravity has adverse effects on aircraft stability and on a pilot’s ability to recover from aerodynamic stalls.
In addition, the pilot utilized a non-standard way of deicing the aircraft by getting isopropyl alcohol from the hardware store. He also departed with ice on the aircraft’s surface, especially on the tail, which causes airflow over the wing and tail to be altered. This severely reduces lift and puts the aircraft closer to its stall region.
The macho attitude the pilot possessed was evidenced when he departed in moderate snow and moderate icing conditions at the surface and claimed the ice would blow off on takeoff.
The words “we need to get home” that the pilot echoed are difficult details surrounding the accident and point to the notion of “get-there-itis.” In the photos of the crash scene from the next day, the skies are completely clear. If the pilot would’ve waited one more day to go home instead of having the mindset that they need to get home now, he could have spared the life of himself and his eight family members.
A lesson for pilots
The pilot of this aircraft incorporated bad habits and attitudes, which forced him into hazardous situations until one cost his life and the life of others. In this case study, pilots can recall the five hazardous attitudes and the antidotes to them:
• Anti-Authority: Follow the rules, they are usually right.
• Impulsivity: Not so fast! Think first.
• Invulnerability: It could happen to me.
• Macho: Taking chances is foolish.
• Resignation: I am not helpless. I can make a difference.
Develop strong habits as a pilot by working to combat these if you see yourself facing a difficult go/no-go decision. Know that you can always wait until the next good weather day to save the lives of yourself and others.
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