Wednesday, December 25, 2019

Loss of Control in Flight: Wittman W-10 Tailwind, N251WT; fatal accident occurred January 23, 2018 near Sauk Centre Municipal Airport (D39), Stearns County, Minnesota

Matthew James Skwira

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

Additional Participating Entities:

Federal Aviation Administration / Flight Standards District Office; Minneapolis, Minnesota
Lycoming; Denver, Colorado

Aviation Accident Factual Report - National Transportation Safety Board:

Investigation Docket - National Transportation Safety Board:

Location: Sauk Centre, MN
Accident Number: CEN18FA083
Date & Time: 01/23/2018, 1530 CST
Registration: N251WT
Aircraft Damage: Substantial
Defining Event:Loss of control in flight
Injuries: 1 Fatal
Flight Conducted Under: Part 91: General Aviation - Personal

On January 23, 2018, about 1530 central standard time, an experimental, amateur-built W-10 Tailwind airplane, N251WT, was substantially damaged when it impacted terrain near Sauk Centre Municipal Airport (D39), Sauk Centre, Minnesota. The pilot sustained fatal injuries. The airplane was privately owned and was operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed throughout the area and no flight plan was filed for the flight, which originated from Cambridge Municipal Airport (CBG), Cambridge, Minnesota, about 1415.

According to witness statements, fuel records, and the pilot's cell phone records, the pilot fueled the airplane with about 7 gallons of fuel and departed D39 about 1200. The pilot landed at Princeton Municipal Airport (PNM), Princeton, Minnesota, about 1244 and departed about 1324. The pilot then landed at CBG about 1341 before departing about 1415. After landing at D39 about 1515, the pilot brought the airplane to a full stop on runway 32, taxied back to the end of the runway, and subsequently departed.

The approximate total flight time from when the pilot originally departed from D39 at 1200, to the time of the accident, was 2 hours 16 minutes, and the total distance flown was about 155 miles. There were no recorded radio communications from the pilot or radar information associated with the airplane. When the pilot did not return as expected, family members contacted authorities and an ALNOT was issued. The airplane wreckage was located about 0820 the next morning about 2.7 statute miles south of D39. The search was assisted by the Air Force Forensic Cellular Team. 

Pilot Information

Certificate: Private
Age: 50, Male
Airplane Rating(s): Single-engine Land
Seat Occupied: Left
Other Aircraft Rating(s):None
Restraint Used:
Instrument Rating(s): None
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed:Yes
Medical Certification: BasicMed None
Last FAA Medical Exam: 08/28/2017
Occupational Pilot: No
Last Flight Review or Equivalent:
Flight Time:  (Estimated) 306 hours (Total, all aircraft), 19 hours (Total, this make and model), 19 hours (Last 90 days, all aircraft), 7 hours (Last 30 days, all aircraft), 2 hours (Last 24 hours, all aircraft) 

The pilot held a private pilot certificate. According to pilot logbook information provided by family members, his total flight experience was about 306 hours. No flight time was logged between July 2012 and September 2017; 24 hours were logged between September 2017 and the accident. The pilot's most recent flight review was completed on September 7, 2017. His first flight in the accident airplane was on October 25, 2017, and he had logged about 18 hours in the airplane before the accident. The pilot did not hold a Federal Aviation Administration (FAA) airman medical certificate but reported that he had completed the requirements for operation under BasicMed on August 28, 2017. 

Aircraft and Owner/Operator Information

Registration: N251WT
Aircraft Category: Airplane
Year of Manufacture: 2017
Amateur Built: Yes
Airworthiness Certificate: Experimental
Serial Number: 1
Landing Gear Type: Tricycle
Seats: 2
Date/Type of Last Inspection: 09/20/2017, Condition
Certified Max Gross Wt.: 1425 lbs
Time Since Last Inspection: 23 Hours
Engines:1 Reciprocating
Airframe Total Time:  as of last inspection
Engine Manufacturer: Lycoming
ELT: Installed, not activated
Engine Model/Series: O-320B1A
Registered Owner: On file
Rated Power: 160 hp
Operator: On file
Operating Certificate(s) Held: None

The airplane, a Wittman Tailwind, was constructed of a steel tube fuselage and wooden wing structure covered with fabric. The airplane was built by the pilot and received its special airworthiness certificate from the FAA on September 20, 2017. According to FAA documents, no defects were noted during the initial airworthiness certification/inspection. The airplane was powered by a Lycoming O-320-B1A engine equipped with a wooden propeller. According to the engine manufacturer's operating manual, the engine consumed about 10 gallons of fuel per hour. Friends of the pilot stated that the pilot usually kept his fuel tank topped off. The fuel tank capacity of the airplane was 32 total gallons.

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: D39, 1242 ft msl
Distance from Accident Site: 3 Nautical Miles
Observation Time: 1535 CST
Direction from Accident Site: 360°
Lowest Cloud Condition: Clear
Visibility:  10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 3 knots /
Turbulence Type Forecast/Actual: / None
Wind Direction: 350°
Turbulence Severity Forecast/Actual:
Altimeter Setting: 30.09 inches Hg
Temperature/Dew Point: -3°C / -9°C
Precipitation and Obscuration:
Departure Point: Cambridge, MN (CBG)
Type of Flight Plan Filed: None
Destination: Sauk Centre, MN (D39)
Type of Clearance: None
Departure Time: 1415 CDT
Type of Airspace: Class E

The reported weather at D39 about the time of the accident included clear skies, 10 miles visibility, and wind from 350° at 3 knots.

Airport Information

Airport: Sauk Municipal (D39)
Runway Surface Type:
Airport Elevation: 1242 ft
Runway Surface Condition: Dry; Ice
Runway Used: N/A
IFR Approach: None
Runway Length/Width:
VFR Approach/Landing: None

Wreckage and Impact Information

Crew Injuries: 1 Fatal
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 Fatal
Latitude, Longitude: 45.659722, -94.930278 

The accident site was located in a large plowed field. The left side of the cabin structure had been moved by first responders. There was no evidence of a postcrash fire and there was no odor of fuel at the site. There was no evidence in the surrounding area of impact with any obstructions prior to ground impact. Signatures at the site indicated that the airplane impacted the ground in an approximate 45° nose-down, wings-level attitude. The cockpit and front structure of the cabin were mostly destroyed by impact forces. The leading edges of both wings were destroyed. The empennage was bent slightly forward and crumpled along its longitudinal length. The fuel tank and fuel lines were compromised. One propeller blade was visible and was relatively undamaged. The second propeller blade was found shattered underneath the engine. The right elevator was found separated from the elevator control system and moved freely. The left elevator was in the full down position and could not be moved.

The engine crankshaft was rotated by hand and drivetrain continuity was established from the propeller to the gearbox. Thumb compression was established on all cylinders. The spark plugs exhibited normal wear patterns. The left and right magnetos were removed but could not be tested due to impact damage. The oil sump was found broken; the engine exhaust and intake pipes were crushed up and aft. The crankshaft flange was deformed, and the starter ring was broken. The oil cooler was crushed aft. The throttle and mixture cables were broken due to impact damage. The carburetor was impact damaged and could not be tested. The fuel lines were compromised by impact damage. No mechanical anomalies were found during the engine examination.

Access panels and fabric were removed to facilitate a detailed flight control examination. Flight control continuity was established from the cockpit to all control surfaces, except the connection to the right elevator control horn. The control horn was found fractured adjacent to a weld joint. The left elevator was connected and appeared undamaged. Examination of the right elevator tubular frame revealed fractures consistent with overstress. Similar overstress fractures were found on the left elevator tubular frame. The overstress fractures were consistent with impact forces. The right elevator skin adjacent to its attachment hinges showed marks consistent with overtravel. The attachment hinges for the left elevator revealed evidence of overtravel in the downward direction. The overstress fractures and overtravel marks were consistent with impact forces. No other anomalies were found during the airframe examination.

Medical And Pathological Information

The Ramsey County Medical Examiner's Office, St. Paul, Minnesota, performed an autopsy of the pilot. The cause of death was blunt trauma. Toxicology testing performed at the FAA Forensic Sciences Laboratory identified no tested-for drugs, ethanol, or carbon monoxide.

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