NTSB Factual Report

HISTORY OF FLIGHT

On April 6, 2013, about 1045 mountain daylight time (MDT), a Cessna 182C, N8721T, collided with terrain 27 miles northwest of Circle, Montana. The private pilot was fatally injured, and the airplane was destroyed. The airplane was registered to Prarie Sky Inc, and was operated by the private pilot as a 14 Code of Federal Regulations, Part 91, personal flight. The airplane departed from a ranch airstrip located approximately 10 miles east of Lustre, Montana, about 1030, in visual meteorological conditions, and was destined for a private airstrip in Acton, Montana.

The pilot told his wife over the phone before he took off that it was a foggy morning but the fog was lifting, visibility had increased to 5 miles, and the weather was supposed to get better in the south. The pilot departed the private ranch air strip about 1030. At 1045, while near Wolf Point, Montanan, he made an airborne mobile phone call to his wife. Just before the mobile connection was dropped he told her that there was fog "just over the river" but it was clear on the other side.

At 1430, concerned family members reported to the Federal Aviation Administration (FAA) that the airplane had never arrived at its intended destination of Acton, Montana. About 1830, the wreckage was located 27 miles northwest of Circle. There were no witnesses to the accident, and no reports of a distress call. Initial examination of the airplane wreckage revealed damage and ground scars consistent with a high energy vertical impact.

PERSONNEL INFORMATION

The pilot, age 38, held a private pilot certificate for airplane single engine land issued February 8, 2013, and a third-class medical certificate issued January 21, 2013, with no limitations. A review of the pilot's logbook revealed that he had 93 hours of total flight time, and 27.5 hours in the accident airplane make and model. A flight review was completed on January 25, 2013, and high performance endorsement entered on February 16, 2013. The pilot did not hold an airplane instrument rating.

AIRPLANE INFORMATION

The four-seat, high-wing, fixed landing gear airplane, serial number 52621, was manufactured in 1960. It was powered by a Continental Motors O-470-L(9)F, 230-hp engine equipped with a two blade McCauley constant speed propeller, model 2A34C203-C. A review of maintenance records showed that the most recent annual inspection was dated June 28, 2012, at a total aircraft time of 7,523.4 hours, and tach time of 100.4, and the engine time since major overhaul (TSMO) was 994.4 hours. The tach reading observed during the wreckage examination was 130.9. At the time of the accident the total airframe time was 7,553.9 hours, and the engine TSMO was 1,024.9 hours.

METEOROLOGICAL INFORMATION

Synoptic conditions: The National Weather Service (NWS) Surface Analysis Chart for 0900 MDT on April 6, 2013, depicted a low pressure system over western Montana at 1007-hectopascals (hPa) with a stationary front extending southeastward across eastern Montana and into the Dakota's. The accident site was located immediately north of the frontal boundary, with a weak pressure gradient area over the area. The station models north and east of the front depicted northerly winds at 10 knots or less, with temperatures in the mid to upper 30's degrees Fahrenheit (F), with temperature-dew point temperatures of 4° or less. South and west of the stationary front winds were from the west, visibility unobstructed, with temperatures in the mid to upper 40's.

An Automated Surface Observation System (ASOS) located at L.M. Clayton Airport (KOLF), Wolf Point, Montana, elevation of 1,989 feet mean sea level (msl), and a magnetic variation of 9° E, reported the following conditions: Wolf Point automated special weather observation at 1028 MDT, wind from 350° at 5 knots, ceiling was overcast at 1,500 feet above ground level (agl), temperature 3° Celsius (C), dew point -1° C, altimeter 29.83 inches of mercury (inHg).

Wokal Field/Glasgow International Airport (KGGW), Glasgow, Montana, was located 42 miles west of KOLF at an elevation of 2,296 feet, and also had an ASOS and reported the following conditions:

0853 Instrument flight rules (IFR), wind from 010 degrees at 4 knots, 10 statute miles visibility, overcast at 700 feet agl, temperature 03C, dew point 02C, altimeter 29.81 inHg

1053, IFR, wind from 020 degrees at 3 knots, 10 statute miles visibility, overcast at 700 feet agl, temperature 04C, dew point 02C, altimeter 29.82 inHg.

1153, IFR, wind from 280 degrees at 3 knots, 10 statute miles visibility, overcast at 900 feet agl, temperature 04C, dew point 02C, altimeter 29.82 inHg

Mesowest Data: An unofficial observation from a citizen weather observation program was obtained. An observation from Circle (D0807) located at 47.6012° N, 105.9653° W, or approximately 6 miles south of the accident site provided the following information at 0958 MDT: wind from the north at 5 knots, temperature 37° F, dew point 35.2° F, relative humidity 93 percent, and a sea level pressure 29.77 inHg. The close temperature-dew point spread and high relative humidity implied low visibility and/or cloud cover over the area.

Sounding: The closest sounding was from Glasgow. The 0600 MDT sounding depicted a surface based temperature inversion and another immediately above it to approximately 4,000 feet. The sounding indicated a relative humidity greater than 80 percent from the surface to 4,000 feet and supported low stratiform type clouds. The freezing level was identified at 4,900 feet agl or 7,200 feet msl. The wind profile indicated light surface wind, which increased above the temperature inversions to the west-northwest at 20 knots and greater. The mean 0 to 6 kilometer (18,000 feet) wind was from 302° at 25 knots. The wind profile supported the later development of mountain wave activity above 6,000 feet.

NWS In-Flight Weather Advisories: The following AIRMET was current over the area:

.

AIRMET, IFR, Montana, from 70 miles south of Swift Current, Canada (YYN), to 50 miles NNW Williston, ND (KISN) to 60 miles SSW Williston, ND (KISN) to 70 miles SW Glasgow (KGGW), to 70 south of Swift Current (YYN), ceiling below 1,000 feet agl, visibility below 3 statute miles and mist. Conditions end between 1200 and 1500.

The observations and satellite imagery supports visual flight rules (VFR) flight into instrument meteorological conditions (IMC) due to low clouds and restricted visibility. The NWS had an AIRMET current for IFR conditions with conditions improving between 1200 to 1500 MDT.

WRECKAGE AND IMPACT INFORMATION

The wreckage was located on a gently sloped area of undisturbed prairie grass. Wreckage debris were spread along a 300-degree magnetic bearing line originating from the main wreckage area and extending out 141 feet. The debris along this line consisted of cockpit overhead structure, left and right wing skins, and portions of wing main spar. The cabin and fuselage structure were completely compressed into itself, and the tail remained the only airframe structure extending above the ground. The engine was embedded vertically in to the Montana gumbo clay soil all the way to the firewall, so that only the firewall wrapped accessory section was all that was identifiable above ground.

All airplane components were located within the accident site. Wing skins from both the left and right wings in addition to spar sections were distributed along the 300-degree magnetic bearing line from the main wreckage, consistent with the direction of travel. The leading edges of both the left and right wings were crushed accordion style. The leading edge damage and the wing skin separation were consistent with the effects of hydraulic deformation of the fuel tanks and overload. All flight control cables were secured at their respective bell crank attach points. Control cables had been cut at multiple locations by first responders. Both ailerons were attached to their respective wing structure; both flaps were attached to their tracks; both elevators were attached to the horizontal stabilizer; and the rudder was attached to the vertical stabilizer. The elevator trim cables were pulled off their sprockets, resulting in unreliable elevator trim measurements.

A Garmin GPSMAP 396 unit was recovered from the wreckage and sent to the NTSB Vehicle Recorders Laboratory for examination. Track log data dated from May 5, 2102, to March 31, 2013, was recovered from the unit. No track log data was identified correlating with the date of the accident. The GPS Factual Report is available in the official docket of this investigation.

On May 15, 2013, the engine was examined under the supervision of an FAA inspector. The engine was a rebuilt and zero timed by Teledyne Continental Motors on September 18, 1996. The last annual inspection was completed on June 28, 2012, at an engine time of 994.0 hours since rebuilt. The propeller governor and oil cooler were fractured free of the engine and not observed. The magnetos were fractured from their mount pads, but remained attached via the ignition harness. The engine and engine accessories exhibited impact damage. The inspection did not reveal any abnormalities that would have prevented normal operation and production of power.

Overall, the wreckage examination did not reveal any anomalies that would have precluded normal operation of the airplane or engine.

MEDICAL & PATHOLOGICAL INFORMATION

An autopsy was performed on the pilot April 9, 2013, by Forensic Medicine and Pathology, PLLC, Billings, Montana, as requested by the McCone County Sheriff. The cause of death was determined to be by severe acute blunt trauma.

The Federal Aviation Administration (FAA) Forensic Toxicology Research Team CAMI performed toxicology on the specimens from the pilot with negative results for carbon monoxide, ethanol, or selected drugs. Testing for cyanide was not performed.

ADDITIONAL INFORMAITON

Spatial Disorientation

Inadvertent VFR flight into IMC is discussed in the Airplane Flying Handbook (FAA-H-8083-3A).

"A VFR pilot is in IMC conditions anytime he or she is unable to maintain airplane attitude control by reference to the natural horizon, regardless of the circumstances or the prevailing weather conditions. Additionally, the VFR pilot is, in effect, in IMC anytime he or she is inadvertently, or intentionally for an indeterminate period of time, unable to navigate or establish geographical position by visual reference to landmarks on the surface. These situations must be accepted by the pilot involved as a genuine emergency, requiring appropriate action.

The pilot must understand that unless he or she is trained, qualified, and current in the control of an airplane solely by reference to flight instruments, he or she will be unable to do so for any length of time. Many hours of VFR flying using the attitude indicator as a reference for airplane control may lull a pilot into a false sense of security based on an overestimation of his or her personal ability to control the airplane solely by instrument reference. In VFR conditions, even though the pilot thinks he or she is controlling the airplane by instrument reference, the pilot also receives an overview of the natural horizon and may subconsciously rely on it more than the cockpit attitude indicator. If the natural horizon were to suddenly disappear, the untrained instrument pilot would be subject to vertigo, spatial disorientation, and inevitable control loss."

NTSB Probable Cause

The pilot’s failure to maintain airplane control as a result of spatial disorientation. Contributing to the accident was the pilot’s decision to continue flight into low visibility conditions.