Sunday, May 23, 2021

Structural Icing: Cirrus SR22 GTS, N809SR; fatal accident occurred May 24, 2019 in Grover, Wayne County, Utah

Lynn Ann Anderson Simonsen and her husband Christian Clinton Simonsen.


Aviation Accident Final Report - National Transportation Safety Board

The National Transportation Safety Board traveled to the scene of this accident.

Additional Participating Entities:
Federal Aviation Administration / Flight Standards District Office; Salt Lake City, Utah
Cirrus Aircraft; Duluth, Minnesota
Continental Motors; Mobile, Alabama

Investigation Docket - National Transportation Safety Board:

Tierra Grande Aviation LLC


Location: Grover, Utah
Accident Number: WPR19FA154
Date & Time: May 24, 2019, 11:16 Local
Registration: N809SR
Aircraft: Cirrus SR22
Aircraft Damage: Destroyed
Defining Event: Structural icing 
Injuries: 2 Fatal
Flight Conducted Under: Part 91: General aviation - Personal

Analysis

The pilot departed on an instrument flight rules cross-country flight and climbed to a cruise altitude of 14,000 ft mean sea level (msl). About 30 minutes into the flight, he requested a climb to 16,000 ft msl. Radar data indicated that over the next several minutes, the airplane climbed to 14,500 ft, then began an increasingly rapid descent as its groundspeed decayed from about 111 knots (kts) to about 64 kts before radar contact was lost. Witnesses reported that they heard the airplane and looked up to see it descending nose down like a corkscrew before it impacted terrain. Postaccident examination of the airframe and engine did not reveal any anomalies that would have precluded normal operation.

AIRMET Zulu for moderate icing conditions was valid for the area of the accident site at the time of the accident, and an atmospheric sounding supported the likely formation of moderate rime and mixed-type icing in the area. The sounding also indicated the potential for supercooled large droplet icing formation near the top of the cloud layer near 15,000 ft msl. Satellite imagery depicted cumulus and cumulus congestus type clouds with vertical development over the flight track and accident site, and weather radar imagery depicted the airplane entering an area of light-to-moderate intensity echoes just before radar contact was lost. Immediately before and after the accident, two other aircraft operating at similar altitudes reported encountering light clear to mixed icing conditions. The pilot had received preflight weather information containing the relevant forecasts and advisories. In addition, the airplane was equipped with a TKS ice protection system, but it was heavily fragmented during the accident sequence and the investigation was unable to determine if the system was activated or working at the time of the accident.

It is likely that, during the last minutes of the flight, the airplane encountered moderate-to-severe icing conditions, which adversely affected the airplane's handling characteristics and likely resulted in a loss of control.

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The pilot's encounter with moderate to severe icing conditions during cruise flight, which resulted in structural icing and a subsequent loss of control. Contributing to the accident was the pilot’s decision to continue a flight route through known moderate to severe icing conditions.

Findings

Environmental issues Conducive to structural icing - Effect on operation
Personnel issues Aircraft control - Pilot
Personnel issues Decision making/judgment - Pilot
Environmental issues Conducive to structural icing - Decision related to condition

Factual Information

History of Flight

Enroute Structural icing (Defining event)
Enroute-change of cruise level Loss of control in flight
Enroute-change of cruise level Collision with terr/obj (non-CFIT)

On May 24, 2019, about 1116 mountain daylight time, a Cirrus SR22 airplane, N809SR, was destroyed when it was involved in an accident near Grover, Utah. The private pilot and passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. 

The airplane departed Canyonlands Field Airport (CNY), Moab, Utah, about 1042. Shortly after takeoff, the pilot contacted air traffic control, opened his instrument flight rules flight plan to Henderson Executive Airport (HND), Las Vegas, Nevada, and was assigned a cruise altitude of 14,000 ft mean sea level. About 1111, the pilot requested to climb to 16,000 ft msl; this was the last communication from the pilot. The airplane climbed from 13,900 ft to 14,500 ft at an average rate of 300 ft per minute and an average groundspeed of 111 knots. Shortly thereafter, the airplane's average groundspeed was 95 knots. The airplane then descended from 14,500 ft to 14,000 ft at an average rate of 833 ft per minute and an average groundspeed of 81 knots. The descent then increased to 2,000 ft per minute at an average groundspeed of 64 knots. Radar contact was lost at 1116.

Witnesses reported to law enforcement that they heard the airplane, then looked up and saw it nose down, descending like a corkscrew. The airplane descended behind a hillside and shortly thereafter, they heard an explosion and saw smoke.

Data recovered from the airplane's Avidyne multifunction display revealed that the engine was producing power until the time of the accident and that cylinder head and exhaust gas temperatures, fuel flow, oil temperature, and oil pressure values were consistent throughout the flight. 

Pilot Information

Certificate: Private
Age: 66, Male
Airplane Rating(s): Single-engine land
Seat Occupied: Unknown
Other Aircraft Rating(s): None 
Restraint Used: 3-point
Instrument Rating(s): Airplane
Second Pilot Present: No
Instructor Rating(s): None Toxicology Performed: Yes
Medical Certification: Class 3 With waivers/limitations 
Last FAA Medical Exam: August 15, 2017
Occupational Pilot: No 
Last Flight Review or Equivalent:
Flight Time: 930 hours (Total, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Make: Cirrus 
Registration: N809SR
Model/Series: SR22 Undesignated
Aircraft Category: Airplane
Year of Manufacture: 2006 
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 2129
Landing Gear Type: Tricycle 
Seats: 4
Date/Type of Last Inspection: April 16, 2019 100 hour 
Certified Max Gross Wt.:
Time Since Last Inspection: 36 Hrs
Engines: Reciprocating
Airframe Total Time: 2672 Hrs as of last inspection 
Engine Manufacturer: Continental Motors
ELT: Installed, not activated 
Engine Model/Series: IO-550-N
Registered Owner: 
Rated Power: 310 Horsepower
Operator: On file
Operating Certificate(s) Held: None

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual (VMC) 
Condition of Light: Day
Observation Facility, Elevation: HVE,4463 ft msl 
Distance from Accident Site: 30 Nautical Miles
Observation Time: 10:55 Local
Direction from Accident Site: 62°
Lowest Cloud Condition: Clear 
Visibility:  10 miles
Lowest Ceiling: None 
Visibility (RVR):
Wind Speed/Gusts: 6 knots / 
Turbulence Type Forecast/Actual: None / None
Wind Direction: 170° 
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting: 30.04 inches Hg 
Temperature/Dew Point: 15°C / 2°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Moab, UT (CNY)
Type of Flight Plan Filed: IFR
Destination: Las Vegas, NV (HND)
Type of Clearance: IFR
Departure Time: 10:42 Local 
Type of Airspace: Unknown

The National Weather Service issued AIRMET Zulu, valid for the area of the accident site about the time of the accident, for moderate icing conditions between around 7,000 ft to 9,000 ft up to 21,000 ft msl. The High Resolution Rapid Refresh numerical model sounding over the accident site depicted a freezing level of 9,755 ft msl and a supported layer of clouds with bases at 10,860 ft msl with tops near 15,000 ft msl; this cloud layer had a greater than 90% probability of producing moderate rime-to-mixedtype icing. The sounding also indicated a mean vertical motion varying from 8 to 14 meters per second, which would enhance the growth of supercooled large droplet formation near the top of the cloud layer. The sounding wind profile supported a high probability of moderate turbulence due to strong vertical wind shear within the cloud environment.

The GOES-17 visible imagery depicted cumulus to cumulus congestus clouds with vertical development over the flight track and accident site, which would also support the formation of larger supercooled water droplets, and vertical motion in the clouds, which would enhance the icing potential. Weather radar imagery depicted several small areas of light-to-moderate intensity echoes of 25 to 35 basic reflectivity values (dBZ) scattered over the area, with most of the echoes within 25 miles of the radar site in the range of 10 to 15 dBZ, or very light intensity. When overlaid with the airplane's flight track, imagery indicated that just before radar contact was lost, the airplane passed through one of these small cells with a maximum intensity of 25.5 dBZ.

Immediately before and after the accident, two other aircraft operating at similar altitudes reported encountering light clear-to-mixed icing conditions.

The pilot filed an instrument flight rules flight plan through ForeFlight before departure and received a corresponding route briefing, which included a description of the conditions and provided the advisory regarding potential icing conditions along the route of flight. 

Wreckage and Impact Information

Crew Injuries: 1 Fatal
Aircraft Damage: Destroyed
Passenger Injuries: 1 Fatal
Aircraft Fire: On-ground
Ground Injuries: 
Aircraft Explosion: Unknown
Total Injuries: 2 Fatal
Latitude, Longitude: 38.174446,-111.24861

The airplane impacted remote mountainous terrain. The debris field was about 330 ft long and was oriented on a magnetic heading of 217°. The airplane was heavily fragmented and scattered perpendicular to a cliffside.

Flight control continuity was established throughout the airframe. The elevator and rudder controls were continuous. The aileron control cable was fracture separated at the control panel and the aileron actuation pulley. Both fractures were consistent with overload. The airplane’s TKS icing protection system, which was not certified for flight into known icing, was found fragmented and scattered throughout the debris field.

The engine was separated from the airframe and came to rest about 211 ft from the initial impact crater. Several components were fracture separated from the engine and scattered throughout the debris field. The crankcase exhibited impact-related damage; there were no signs of catastrophic engine failure. The crankshaft was bent just aft of the propeller flange. The crankshaft gear displayed normal operating signatures. All six cylinders remained attached to the cylinder bays; the right-side cylinders exhibited more damage than the left side cylinders. Borescope examination of the cylinder bores, piston faces, and valve heads displayed normal operating signatures. The fuel pump was removed from the engine and the driveshaft was rotated; residual fuel pumped through the line. The upper and lower spark plugs exhibited normal operating signatures. The oil filter was removed from the engine and cut open; no metallic material was noted. The propeller assembly remained attached to the engine and the three blade shanks remained attached to the hub.

Postaccident examination of the airframe and engine revealed no anomalies that would have precluded normal operation.

Medical and Pathological Information

The Office of the Medical Examiner from the Utah Department of Health, Taylorsville, Utah performed an autopsy of the pilot and determined the cause of death to be "multiple injuries".

The FAA Forensic Sciences Laboratory performed forensic toxicology on specimens from the pilot with positive results for cetirizine which is not considered a hazard to flight safety.

Christian Clinton Simonsen







































6 comments:

  1. Tragic accident...I question if there was a ballistic chute...why was it not deployed ?

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    Replies
    1. There was - they're on all -20s and -22s as they're required. I recently completed the chute training and Cirrus very much stresses pulling it the moment you lose control or spatial orientation. That I'm sure comes from years of folks thinking they could fly it out and not wanting to admit failure by pulling the chute. Ego will get you killed in this business (see above).

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  2. Looks like an airplane with a thick heavy coating of ice develops all the flying characteristics of a brick. Judging from the photos the impact speed must have been terrific. A very sad end to the pilot and his wife. RIP>

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  3. One would think that Cirrus would have designed an automatic deployment trigger if flight dynamics exceed design limit and no action by a certain time is taken by the pilot to 1) recover or 2) pull the CAPS. It could be easily done with sensors tied from the avionics to the CAPS system. And the trigger could also be set based on AGL remaining and not just time when out of control. Possibly could have saved their lives here. An airfoil ruined by ice sending the aircraft out of control has a slim to none chance of recovery. Never mind the Cirrus is not certified for spins. So sorry for their family and friends.

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  4. Hard to fathom why they did not deploy the chute that would have saved them. Possibly, they could not overcome the centrifugal forces in the spin. Maybe the wife had taken off her belt and was thrown onto him? They had nearly 5 minutes to find the handle. You would think you would find the handle, but the handle was still in its home position. Nice looking couple. RIP.

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