N7915FCessna 150F · 1966

On September 26, 2010, at 1059 eastern daylight time, a Cessna 150F, N7915F, owned and operated by a private individual, was substantially damaged during impact with trees and terrain, while maneuvering near Sweetwater, Tennessee. The certificated private pilot was killed. Instrument meteorological conditions prevailed and no flight plan was filed for the planned flight to Knoxville Downtown Island Airport (DKX), Knoxville, Tennessee. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. The flight originated from Cobb County Airport (RYY), Marietta, Georgia, about 0945.

According to owner/operator, the airplane was based at DKX and the pilot was a friend who borrowed the airplane to visit family. On September 24, 2010, the pilot flew uneventfully from DKX to Columbus-Lowndes County Airport (UBS), Columbus, Mississippi. After the trip, the pilot telephoned the owner and reported that the airplane performed well. On September 25, 2010, the pilot flew uneventfully from UBS to RYY. The pilot was returning from RYY to DKX when the airplane impacted a hill located about 6 miles northwest of Monroe County Airport (MNV), Madisonville, Tennessee. Two witnesses in the area reported hearing an airplane "sputter" and then crash into a ridgeline. One witness stated that the airplane appeared to approach from the east. The other witness stated that the area was foggy and she did not see the impact.

According to radar data provided by the Federal Aviation Administration (FAA), a target with a transponder code of 1200 was recorded traveling northeast from RYY. The target was indicating an altitude of 3,900 feet mean sea level (msl) at 1039, then 3,000 feet at 1044, where it remained until 1058. At that time, the target began a right turn, followed by a descending left turn. The last radar target was recorded at 1059:28, about 1/4 mile northwest of the accident site, with an associated altitude of 1,600 feet msl.

The pilot, age 64, held a private pilot certificate with a rating for airplane single-engine land. The pilot did not possess an instrument rating. His most recent FAA third-class medical certificate was issued on July 22, 2009. According to the pilot's logbook, he had accumulated a total flight experience of 329.6 hours; of which 24 hours were logged as simulated instrument conditions and none were logged as actual instrument conditions. None of the simulated instrument experience was logged within the 10-month period preceding the accident. The pilot had flown 5.6 hours during the 90-day period preceding the accident, not counting the recent flights to UBS and RYY, which had not been recorded in the logbook.

The two-seat, high-wing, fixed-gear airplane, serial number 15064015, was manufactured in 1966. It was powered by a Continental Motors O-200, 100-horsepower engine, equipped with a McCauley fixed-pitch propeller. Review of the airplane's logbooks revealed that its most recent annual inspection was completed on July 3, 2010. At that time, the airplane had accumulated 3,582.8 total hours of operation. The engine had also accumulated 3,582.8 total hours of operation since new, and 1,986.8 hours since overhaul. The airplane had flown about 13 hours since the most recent annual inspection.

According to data from Lockheed Martin, the pilot contacted a flight service station on September 25, 2010, for the flight from UBS to RYY. During that telephone conversation, the pilot filed a visual flight rules flight plan. The weather briefer asked the pilot if he was familiar with the adverse weather conditions along the planned route of flight, and the pilot replied yes. There was no record of the pilot contacting a flight service station or data user access terminal for the accident flight the following day.

The recorded 0947 weather at RYY was: wind calm; visibility 10 miles; scattered clouds at 700 feet; overcast ceiling at 4,800 feet, temperature 21 degrees Celsius (C); dew point 19 degrees C; altimeter 29.92 inches of mercury.

The recorded 1056 weather at MNV, located at 1,031 feet msl, was: wind from 320 degrees at 4 knots; visibility 9 miles; overcast ceiling at 600 feet; temperature 17 degrees C; dew point 17 degrees C; altimeter 29.93 inches of mercury.

The wreckage was located about 1,300 feet mean sea level (msl). All major components of the airplane were accounted for at the scene. No debris path was noted, except for two scarred trees, oriented from north to south. The airplane came to rest upright, left wing down, nose low, on a heading of approximately 060 degrees magnetic.

The empennage remained intact with minor damage noted to the elevator and rudder. Both wings remained attached to the airframe. The left aileron was resting in an upward position, the right aileron was in a downward position, and the flaps were retracted. The left wing fuel tank was approximately three-fourths full of fuel. The fuel appeared bright, clear, and consistent with 100-low-lead aviation gasoline. The cockpit area was crushed. The throttle lever was found near the idle position and the mixture was in the rich position. The carburetor heat was off and the magneto switch was positioned to "Both." The airspeed indicator was positioned at 170 knots and the attitude indicator was tumbled.

After the wreckage was recovered from the hill, aileron control continuity was confirmed from the cockpit controls to each wing root, where the cables had been cut by recovery personnel, and then to the left and right ailerons, respectively. Elevator, elevator trim, and rudder control cable continuity was confirmed from the cockpit controls to the forward empennage section, where the cables were cut by recovery personnel, and then to their respective control surfaces. A measurement of the elevator trim jackscrew revealed an approximate 5-degree tab up position.

The engine remained attached to the airframe and the propeller remained attached to the engine. One propeller blade exhibited s-bending and chordwise scratches. The other propeller blade exhibited chordwise scratching and polishing. The propeller was rotated freely by hand. Camshaft, crankshaft, and valvetrain continuity was confirmed and thumb compression was attained on all cylinders. The top spark plugs were removed for inspection; their electrodes were intact and light gray in color. The carburetor was disassembled and examined. The examination revealed that the floats and needle valve remained intact.

An autopsy was performed on the pilot on September 27, 2010, by the University of Tennessee Medical Center, University Pathologists, P.C., Knoxville, Tennessee.

Toxicological testing was performed on the pilot by the FAA Bioaeronautical Science Research Laboratory, Oklahoma City, Oklahoma. Review of the toxicology report revealed:

"Propranolol detected in Liver

Propranolol detected in Blood."

On the pilot's most recent application for an FAA third-class medical certificate, under "18. Medical History, h. High or low blood pressure," the pilot indicated "Yes, h. - slightly high B P."

A handheld global positioning system (GPS) receiver was recovered in the wreckage and retained for further examination by the NTSB Vehicle Recorders Laboratory, Washington, DC. Data was successfully downloaded from the unit; however, the make and model GPS unit did not record time or altitude, only position track points. The track points depicted a northwest track from RYY toward Dalton Municipal Airport (DNN), Dalton, Georgia, then a northeast track toward DKX, consistent with the observed radar data.

Review of FAA Advisory Circular 60-4A revealed:

"The attitude of an aircraft is generally determined by reference to the natural horizon or other visual references with the surface, if neither horizon or surface references exist, the attitude of an aircraft must be determined by artificial means from the flight instruments. However, during periods of low visibility, the supporting senses sometimes conflict with what is seen, when this happens, a pilot is particularly vulnerable to disorientation. The degree of disorientation may vary considerably with individual pilots, Spatial disorientation to a pilot means simply the inability to tell which way is up."