HISTORY OF FLIGHTOn December 22, 2014, about 0852 central standard time, a Cessna 172M, N9922V, impacted terrain after a loss of control about 8 nautical miles northwest of the Odessa Airport – Schlemeyer Field (ODO), Odessa, Texas. The airplane was destroyed by a postimpact fire. The commercial pilot was fatally injured. The airplane was owned and operated by American Patrols Inc. under the provisions of the 14 Code of Federal Regulations Part 91 as an aerial survey flight. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed. The airplane departed Skywest Airport Inc. (7T7), Midland, Texas, about 0800 on a local aerial pipeline patrol. Three witnesses reported seeing the airplane flying at 400 – 500 ft above ground level (agl) when it went into a steep left bank, and then it "nosed dived" into the ground. One witness estimated that the angle of bank was approximately 80 degrees. Soon after, smoke and flames were observed coming from the accident site. A witness who arrived at the accident site soon after the accident occurred, reported that the airplane was engulfed in flames, with the tail of the airplane in a vertical position and the wings flat on the ground. PERSONNEL INFORMATIONThe 28 year-old pilot held a commercial certificate with single-engine and multi-engine land ratings, and an airplane instrument rating. According to a witness, the pilot had about 2,000 hours of total flight time with about 1,200 hours in make and model. He held a first class medical certificate that was issued on October 29, 2014, with a limitation for corrective lenses. The pilot was hired by American Patrols in January 2014. According to an insurance form, he had 505 hours of total time and 282 hours in a Cessna 172 when he was hired. A pilot employed by American Patrols reported that he shared an apartment with the accident pilot. He reported that the accident pilot flew on Saturday, December 20th for about 6 hours and 3.5 hours on Sunday. He was not certain when the accident pilot went to sleep on Sunday night, but he stated that the accident pilot normally went to sleep around 2230. He heard the accident pilot getting ready for work about 0645 on Monday morning and leave for work shortly after that time. AIRCRAFT INFORMATIONThe airplane was a single-engine Cessna 172M, serial number 17264557, manufactured in 1975. It was equipped with a Lycoming 160-horsepower O-320-E2B engine, serial number L-33411-27A. The last annual maintenance inspection was conducted on November 29, 2014, with a total airframe time of 13,694 hours. The engine had a total time of 11,130 hours with 202 hours since the last overhaul conducted on October 3, 2014. METEOROLOGICAL INFORMATIONAt 0853, the surface weather observation at ODO was: wind 290 degrees at 8 knots, 10 miles visibility, sky clear, temperature 12 degrees C, dew point -2 degrees C, and altimeter 29.76 inches of mercury. AIRPORT INFORMATIONThe airplane was a single-engine Cessna 172M, serial number 17264557, manufactured in 1975. It was equipped with a Lycoming 160-horsepower O-320-E2B engine, serial number L-33411-27A. The last annual maintenance inspection was conducted on November 29, 2014, with a total airframe time of 13,694 hours. The engine had a total time of 11,130 hours with 202 hours since the last overhaul conducted on October 3, 2014. WRECKAGE AND IMPACT INFORMATIONThe airplane impacted the flat, sandy terrain dominated by oil fields. The wreckage was confined to the initial impact point, with the nose of the airplane aligned on a 205 magnetic heading. The propeller remained on top of the ground under the engine, but it was separated from the propeller flange. Much of the engine compartment, instrument panel, cabin, and aft fuselage were consumed by the postimpact fire. The empennage remained intact and was not damaged by the ground fire. The leading edges of the left and right wings exhibited aft crushing, with the left outboard wing section exhibiting more aft buckling than the right wing. The leading edge crush angle was consistent with about a 30- to 40-degrees nose down, left wing low attitude. The left and right wings were consumed by fire from the wing root to about mid-span. Flight control cable continuity was confirmed from the flight controls to their respective attach points on the flight control surfaces. The flaps were found in the up position. The elevator trim tab was found in a 10-degree tab up position. The fuel strainer was fire damaged, but the fuel strainer screen was clean. The examination of the propeller revealed that both blade tips were consumed by fire. Chordwise scratching was evident on one of the blades. Both blades exhibited blade twist and aft bending. The propeller attachment bolts were sheared from the propeller flange opposite the direction of rotation. The propeller flange bolt holes exhibited elongation. The examination of the engine revealed that it could not be rotated. The Nos. 1 and 3 cylinders were removed from the crankcase. Except for the fire damage, no damage to the cylinders was noted. The crankshaft and camshaft were viewed through the cylinder base openings and no damage other than thermal discoloration was noted. The carburetor was crushed and partially consumed by the fire. Both magnetos were separated from the engine and partially consumed by the fire. The exhaust system was crushed and all of the engine accessories were fire damaged. The oil suction screen was clean. ADDITIONAL INFORMATIONThe Cessna Pilot's Operating Handbook (POH) figure 6-2 lists stall speeds corrected for aircraft bank angle. The stall speed for a Cessna 172 at 2,300 lbs with flaps up at 0 degrees angle of bank is 57 mph. With the same configuration, it shows the stall speed is 81 mph at 60 degrees of bank, and would have been higher at the 80 angle degrees of bank reported by witnesses. Cessna's operating limitations do not allow aerobatic operations or banks in excess of 60 degrees. Cessna recommends entering steep turns at 112 mph. The "Airplane Flying Handbook FAA-H-8083-3A" provided the following information about accelerated stalls: "Though the stalls just discussed normally occur at a specific airspeed, the pilot must thoroughly understand that all stalls result solely from attempt to fly at excessively high angles of attack. During flight, the angle of attack of an airplane wing is determined by a number of factors, the most important of which are airspeed, the gross weight of the airplane, and the load factors imposed by maneuvering. At the same gross weight, airplane configuration, and power setting, a given airplane will consistently stall at the same indicated airspeed if not acceleration is involved. The airplane will, however, stall at a higher indicated airspeed when excessive maneuvering loads are imposed by steep turns, pull-ups, or other abrupt changes in the flight path. Stalls entered from such flight situations are called 'accelerated maneuver stalls,' a term, which has no reference to the airspeeds involved." The American Patrols, Inc. published revision 8 of its Operation Manual on December 23, 2015. Revision 8 stated the following concerning the Scope of Operations: "Normal and routine patrol operations require close examination of the production field or the pipeline right-of-way. This can generally be accomplished at an altitude of 500 feet AGL and is often performed at between 500 feet and 700 feet AGL. In the event that a condition or anomaly is observed in the field or along the right-of-way it may be necessary for the pilot to descend below 500 ft AGL to make a closer observation. Descents below 200 ft AGL are prohibited. Operations below 500 ft AGL are governed by the "Low Altitude Waiver" which is covered in this Manual. Patrol flights conducted below 1,000 feet will not exceed 45 degrees of bank and/or 20 degrees of pitch up or down. All maneuvers will be performed without abrupt control inputs or excessive back pressure to minimize the risk of a stall." American Patrols, Inc. published its latest Pilot Training Manual on December 23, 2015. The following information was in a box and highlighted by yellow: "In order to minimize the risks associated with flights below 1,000 ft, the maximum bank angle permitted is 45 degrees and the maximum pitch up or down is 20 degrees. All maneuvers will be performed without abrupt control inputs or excessive back pressure to minimize the risk of a stall." MEDICAL AND PATHOLOGICAL INFORMATIONAn autopsy of the pilot was conducted at the Tarrant County Medical Examiner's District morgue in Fort Worth, Texas, on December 26, 2014. The cause of death was blunt force trauma due to an airplane crash. A Forensic Toxicology Fatal Accident Report was prepared by the FAA Civil Aerospace Medical Institute. The results were negative for all substances tested. TESTS AND RESEARCHRadar track data indicated that an aircraft transmitting a 1,200 transponder code departed from 7T7 about 0800 on December 22, 2014 and flew to the northwest at 500 to 800 ft agl. It entered a north/south grid pattern flight path with 12 to 13 mile legs, which was consistent with a flight path used by oil pipeline pilots when checking for oil or water leaks. About 0848, the radar track data indicated that the aircraft entered a series of turns near the location of the accident site. At 08:50:58, the last radar return indicated that the aircraft was about 300 ft agl and less than 0.5 miles to the west of the accident site. On December 25, 2014, an American Patrols pilot overflew the area where the accident occurred. He spotted a large water leak about 0.3 miles to the north-northwest of the accident site. A "pumper" (an oilfield worker who provides spill remediation) estimated that it had been leaking for a few days in order for the leak to get that large. The location of the water leak was about 0.2 miles from the last radar return.