N4428QCessna 172M · 1973

On November 24, 2010, approximately 1500 central standard time, a Cessna 172M, N4428Q, registered to and operated by Eagle Sky Patrol, Inc., Nemo, South Dakota, was destroyed when it impacted terrain while maneuvering at low altitude 8 miles east of Velma, Oklahoma. Visual meteorological conditions (VMC) prevailed at the time of the accident. The aerial observation flight was being conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 91 without a flight plan. The pilot, the sole occupant on board the airplane, was fatally injured. The flight originated at Ardmore (1F0), Oklahoma, approximately 1400, and was destined for Terrell (TRL), Texas.

According to the Federal Aviation Administration (FAA) inspector who went to the scene, the pilot was flying pipeline surveillance. He landed at Ardmore (1F0), Oklahoma, and the airplane was refueled. He then departed 1F0 to continue patrolling. A witness said the pilot circled an oil derrick several times, flew in a straight direction, turned, and began circling again. The airplane was circling from the south and turned back towards the west when the nose dipped and the airplane descended, striking power lines before impacting the ground.

Another witness said the airplane was approximately 150 feet in the air when it passed overhead. The witness waved at the pilot and the pilot waved back. He said the pilot was making left hand turns. The engine sounded normal. He turned away, then heard the airplane hit the power line. There were two other witnesses who gave similar statements.

There was fire after ground impact. There were no radio communications between the pilot and the ground crew; the pilot used visual cues only.

The pilot, age 48, held a commercial pilot certificate with airplane single/multiengine and instrument ratings, and a flight instructor certificate with an instrument rating. His first class airman medical certificate, dated June 16, 2010, contained no restrictions or limitations.

The pilot's logbook was never located. According to the FAA inspector, he estimated the pilot's total flight time to be 1,269.2 hours. This figure was based on an October 2010 insurance application while the pilot was employed by Eagle Sky Patrol. Added to that were the number of hours he had flown for Eagle Sky Patrol from the time he completed the application until the time of the accident. Finally, based on witness accounts and refueling logs, the hours the pilot flew on the day of the accident were included.

According to the accident pilot's trainer, he had been flying pipeline patrols for approximately 4 months, and had no previous pipeline patrol experience.

N4428Q, a model 172M (s.n. 17261707), was manufactured by the Cessna Aircraft Corporation in 1973. It was powered by a Lycoming O-320-E2D engine (s.n. L-34067-22A), rated at 150 horsepower, driving a McCauley 2-blade, all-metal, fixed pitch propeller (m.n. 1C160/CTM7553).

According to the operator, the pilot kept the airplane's maintenance records. Those records have not been located.

The following METAR (Aviation Routine Weather Report) was recorded at 1511 central standard time at Halliburton Field (DUC), Duncan, Oklahoma, located approximately 20 miles west of the accident site:

Wind, 210 degrees at 15 knots, gusts to 19 knots; visibility, 10 statute miles; sky condition, clear; temperature, 27 degrees C. (Celsius); dew point, 12 degrees C.; altimeter, 29.60 inches of Mercury.

On November 26, 2010, an FAA inspector and a Cessna Aircraft Corporation representative examined the wreckage at the accident site. The airplane struck 30-foot high power lines as it descended to the ground, coming to rest inverted approximately 90 feet from the initial point of impact. There was continuity between all primary and secondary flight controls and the cabin area. Measurement of the elevator trim tab actuator revealed 10 degrees tab up. Measurement of the flap jackscrew revealed the flaps were up. The fuel selector was on BOTH. There was S-bending of the propeller, and it bore chordwise scratches on the cambered surface.

On November 28, 2010, an autopsy was performed on the pilot by the Oklahoma State Medical Examiner's Office. Death was attributed to "multiple blunt force trauma."

Toxicological screens were conducted by both the Oklahoma State Medical Examiner's Office and FAA's Civil Aeromedical Institute (CAMI). The Oklahoma State Medical Examiner's Office report noted 0.03% ethanol in blood and less than 5 per cent carbon monoxide saturation in blood. CAMI's report also detected ethanol in blood and muscle, but noted putrefaction of the specimens. Additionally, 2.429 (ug/ml, ug/g) acetaminophen (Tylenol) was detected in blood (cavity).

According to a friend who trained the pilot for this job, the pilot had been flying for Eagle Sky Patrol for approximately 4 months. Although he was a flight instructor, he had no previous pipeline patrol experience. Witnesses told him the pilot was circling around a pipeline leak and was attempting to guide a ground crew. "He had made four tight circles around the location, and as he began the fifth circle, he rolled into a hard left turn and the aircraft stalled, rolled inverted, and fell to the ground, taking out the on the way down."

The pilot-friend added, "You never circle a location more than twice without flying out from it and coming back, due to the fact that you're flying through your own vortices and prop wash, and being in such tight turns, your airspeed and energy are constantly dropping. Add to that some strong gusty winds, divided attention between flying, staying on the location you're circling, talking on the radio to your ground crews, it's a lot to handle, even on a good day, much less a windy rough day like last Wednesday was."