N2435RCessna 172R · 2006

On September 19, 2014, about 0740 central daylight time, a Cessna 172R airplane, N2435R, impacted terrain near Okmulgee, Oklahoma. The private pilot was fatally injured and the airplane was substantially damaged. The airplane was registered to Spinks Leasing Inc. and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Instrument meteorological conditions prevailed for the flight that operated without a flight plan. The flight departed the Fort Worth Spinks Airport (KFWS), Fort Worth, Texas, about 0500, and was en route to the Richard Lloyd Jones Jr. Airport (KRVS), Tulsa, Oklahoma.

The pilot was reported as overdue and was the subject of an Alert Notice (ALNOT). The airplane wreckage was discovered by local law enforcement and the Civil Air Patrol. The airplane wreckage was located in a field surrounded by trees. There are no known witnesses to the accident. In addition, there are no known communications with air traffic control and no known distress calls.

The pilot, age 63, held a private pilot certificate for airplane single engine land and instrument airplane. On November 15, 2012, the pilot was issued a third class medical certificate and his special issuance was renewed. The special issuance was for diabetes and glaucoma conditions. The medical certificate was not valid for any class after November 30, 2014. On the pilot's application for his medical certificate, he reported having accumulated 720 hours with 60 hours logged in the preceding six months. The pilot's log book was not recovered and it is unknown how often the pilot flew. The pilot's most recent flight review was conducted on September 14, 2013, in a Cessna 182T airplane.

According to the pilot's widow, the pilot was an early riser and had gone to sleep the night prior about 2000 hours. She could not recall if he awoke in the night. All of the pilot's medical conditions that she had knowledge of had been reported to the Federal Aviation Administration (FAA). She reported no recent change in the pilot's medical history.

The Cessna 172R was a 4-four seat, high wing, single engine airplane manufactured in 2006. It was powered by a 180 horsepower Lycoming IO-360-L2A engine driving a 2 bladed, metal McCauley propeller. The airplane last inspection was annual type conducted on August 20, 2014, at a total airframe time of 3,517.1 hours, tachometer of 3,491.3 hours, a Hobbs meter of 4,469.7 hours, total engine time of 3,517.1 hours and 676.4 hours since major overhaul. No major maintenance discrepancies existed for the accident airplane.

According to electronic records, the pilot obtained Direct User Access Terminal Service (DUATS) flight information to include weather at 0311:34 and that online session terminated at 0311:37. During that information exchange, DUATS provided terminal aerodrome forecast (TAF) for KRVS that stated the forecast from 0300 CDT onward expected a calm wind, 4 miles visibility and mist, scattered clouds at 2,500 feet above ground level (agl). Temporary conditions of 1 mile visibility, mist, and scattered clouds at 500 feet agl were forecast between 0500 and 0900 CDT. In addition, Airmen's Meteorological Information (AIRMET) was provided for instrument flight rules conditions of ceilings below 1,000 feet agl and visibility below 3 miles due to precipitation and mist for the pilot's intended route of flight. The pilot intended route of flight was to depart KFWS at 0500 CDT and proceed direct to KRVS at an altitude of 7,500 feet. There is no record of the pilot obtaining further weather information prior to his departure.

At 0345 CDT, an additional AIRMET was issued at 0345 CDT and this forecast mentioned IFR conditions at the takeoff and destination locations due to precipitation and mist. This forecast would have been available to the pilot well before the 0500 CDT takeoff time and would have shown that the IFR area had increased from the 2145 CDT, September 18 forecast. IFR conditions were forecast to continue beyond 1000 CDT and ending between 1000 and 1300 CDT. While the pilot was en route to his destination, at 0533 CDT, an additional AIRMET was issued for additional IFR conditions in western Texas and Oklahoma, while the IFR conditions at the takeoff and destination locations remained the same.

At 0455, an automated weather observation facility at KFWS reported wind calm, 4 miles visibility, mist, clear sky, temperature of 20° Celsius (C), and a dew point temperature of 19° C. About fifteen minutes after the pilot's departure, KFWS reported wind calm, 2.5 miles visibility, mist, scattered clouds at 1,000 feet agl, temperature 19° C, and a dew point temperature of 19° C.

At the 0735, the nearest automated weather observation facility was Okmulgee Municipal Airport (KOKM), Okmulgee, Oklahoma, located 3.5 miles south-southeast of the accident site reported wind from 150° at 5 knots, 2.5 miles visibility, mist, overcast ceiling at 200 feet agl, temperature of 20° C, and a dew point temperature of 20° C. In addition, the pilot's intended destination, KRVS, was located about 22 miles north of the accident site. At 0753, at RVS reported a wind from 160° at 5 knots, 4 miles visibility, mist, overcast ceiling at 400 feet agl, temperature of 21° C, and a dew point temperature of 20° C.

Visible and infrared data from the Geostationary Operational Environmental Satellite number 13 found that due to similar cloud top and ground temperatures, cloud top information was unreliable. Comparing the brightness temperatures against temperatures obtained during an upper air sounding, returned an approximate cloud top height of 3,000 feet mean sea level (msl).

The Cessna 172R was a 4-four seat, high wing, single engine airplane manufactured in 2006. It was powered by a 180 horsepower Lycoming IO-360-L2A engine driving a 2 bladed, metal McCauley propeller. The airplane last inspection was annual type conducted on August 20, 2014, at a total airframe time of 3,517.1 hours, tachometer of 3,491.3 hours, a Hobbs meter of 4,469.7 hours, total engine time of 3,517.1 hours and 676.4 hours since major overhaul. No major maintenance discrepancies existed for the accident airplane.

The airplane wreckage was located in a field surrounded by trees in an area of rolling hills. The wreckage path followed a 110 degree heading and was about 3.5 miles northwest of the Okmulgee Regional Airport (KOKM). The first impact points consistent of tall trees. A portion of the right elevator was located in one of the trees. About 75 feet from the tree line was a ground scar. Impact signatures were consistent with impact of the fuselage at a 10° nose low attitude. The propeller was impact separated at the propeller hub and was located at the end of the ground scar. The right wing separated from the fuselage and was fractured into two major portions outboard of the wing strut. These portions contained at least two semi-circular indentions consistent with tree strikes. The main wreckage came to rest about 210 feet past the ground scar. It consisted of the cockpit area, fuselage, and empennage. The horizontal stabilizer, rudder, vertical stabilizers and elevators had separated just aft of the empennage but remained attached to the airplane by their flight control cables. The inboard portion of the left wing, to include the aileron and flap were located just northwest of the main wreckage. The engine and firewall had separated from the airplane and came to rest about 25 feet past the main wreckage in a tree line.

There were multiple fractures in both aileron control cables. All fractures displayed broomstrawing of the cables. Control continuity was established from the cockpit controls to the elevator and rudder flight control surfaces. The flap actuator indicated that flaps were up. Elevator trim was found at neutral (0°). The cockpit instruments were largely impact damaged and unreadable.

The engine was examined on-scene. Engine continuity and thumb compression was established. The propeller had sheared from the engine at the propeller flange. Both magnetos and the engine driven fuel pump were impact separated and destroyed. The throttle body was impact damaged. Both blades of the propeller displayed s-bending, curling, polishing, chordwise scratches and angular scratches. No preimpact anomalies were detected with the engine or airframe.

The airplane was equipped with a Garmin G1000 integrated avionics system. The G1000 was impact damaged and the secure digital memory card containing flight information was not located. Only the map database memory was located in the wreckage.

Radar information

There was no record of the pilot talking to any tower or air traffic control personnel. Radar information was examined for evidence of the accident airplane's flight. About 0503 CDT, an airplane transmitting the beacon code 1200 was recorded departing from KFWS to the southeast before turning north bound. The airplane proceeded towards KRVS at an altitude between 2,500-4,000 feet mean sea level. When the airplane was over Beegs, Oklahoma, it began to make several turns. It approached the town from the south about 3,600 feet msl and made 360° turn (with about a 1 mile diameter) and descended to 2,200 feet msl. The airplane then flew another 360° turn that increased in diameter and descended to 1,900 feet msl. Next, the airplane performed a teardrop turn that descended to 1,300 feet msl (about 430 feet agl) before climbing to 1,700 msl and leaving Beegs to the northeast. The airplane then flew west of the initial approach points for the instrument approaches to KOKM. At 0731:52, the airplane was at 1,200 feet msl (about 325 feet agl) and momentarily disappeared from radar and reappeared at 0733:41 at an altitude of 1,300 msl. It appeared to be flying southeast before it made a slight S-turn towards the southwest and began to climb. Then the airplane turned to the northwest away from the airport. The last radar return occurred at 0736:29 as the airplane is flying to the north at an altitude of 1,700 msl. This last return was about ½ miles east of accident site. The lowest cloud layer in this area was an overcast ceiling of 900 ft msl or about 200 ft above ground level.

During the airplane's maneuvering north of OKM, it never aligned with the runway extended centerline and the maneuver to the northwest was not consistent with any published missed approach procedure.

An autopsy was authorized and conducted on the pilot by the Office of the Chief Medical Examiner, Tulsa, Oklahoma. The autopsy noted the presence of mild atherosclerotic stenosis of the left anterior descending coronary artery. In addition, concentric left ventricular hypertrophy consistent with hypertensive cardiomyopathy was also noted. The cause of death was due to multiple blunt force injuries. The manner of death was ruled an accident.

The FAA Civil Aerospace Medical Institute performed forensic toxicology on specimens from the pilot. The specimens received displayed evidence of putrefaction. The report listed the following results:

53 (mg/dL, mg/hg) Ethanol detected in Blood (Cavity)

15 (mg/dL, mg/hg) Ethanol detected in Kidney

NO ETHANOL detected in Liver

N-Propanol detected in Blood (Cavity)

Atenolol detected in Liver and Blood (Cavity)

Diphenhydramine detected in Liver

0.034 (ug/ml, ug/g) Diphenhydramine detected in Blood (Cavity)

Irbesartan detected in Liver and Blood (Cavity)

Rosuvastatin detected in Liver and Blood (Cavity)

Due to a lack of ethanol in the liver, it is likely that the ethanol was from sources other than ingestion.

Diphenhydramine is a common over the counter antihistamine used in the treatment of the common cold and hay fever. Irebesatan is used mainly for the treatment of hypertension. Rosuvastatin is used to treat high cholesterol and related conditions, and to prevent cardiovascular disease. On his most recent medication application, dated November 15, 2012, the pilot reported the use of irbesatan and rosuvastatin. In addition, the pilot reported the use of insulin glargine, insulin aspart injection, canagliflozin, testosterone, niacin, and montelukast. The pilot provided documentation to maintain his special issuance for type II diabetes which included an eye evaluation, glaucoma evaluation, as well as information from his endocrinologist. The FAA's Aerospace Medical Certification Division renewed the pilot's special issuance on February 11, 2014.

A review of the pilot's medical information found no evidence of a medical condition contributing to the accident.