HISTORY OF FLIGHTOn August 22, 2017, about 1100 Pacific daylight time, a Rockwell International S2R agricultural airplane, N5022X, was destroyed by a collision with terrain and postcrash fire about 8.5 miles east of Calipatria, California. The commercial pilot was fatally injured. The airplane was registered to the Bank of Utah and was being operated by Farm Aviation, Inc., under the provisions of Title 14 Code of Federal Regulations Part 137. Visual meteorological conditions prevailed, and no flight plan was filed for the aerial application flight. The local flight originated about 1050 from an unimproved dirt airstrip about 4 miles from the accident location. The accident flight was the pilot's second chemical load flight of the day. The first flight originated from Brawley Municipal Airport (KBWC), Brawley, California, about 1020. According to a witness located about 100 yards from the accident location, the airplane completed an agricultural spray pass from west to east. As the airplane approached the witness's position, it began a turn to reverse course and re-enter the spray area. Following a slight right turn, the airplane rolled wings level, and the witness anticipated that it would enter a left turn back to the field. When the wings were rolled level, at an estimated altitude of between 150 ft above ground level (agl) and 200 ft agl, the nose dropped, and the airplane impacted the field in near vertical attitude. A postimpact fire ensued, which consumed most of the airplane's fuselage, left wing, and empennage. PERSONNEL INFORMATIONThe pilot, age 40, held a commercial pilot certificate with airplane single- and multi-engine land and instrument ratings. The pilot also held a flight instructor certificate with airplane single-engine and instrument ratings. The pilot was issued a second-class airman medical certificate on April 26, 2017, without any limitations. On the application for this medical certificate, the pilot reported that he had accumulated 2,210 total hours of flight experience of which 280 hours were in the last 6 months. The pilot was involved in an aviation accident (WPR17LA174) in a different agricultural airplane on August 1, 2017; this accident is still under investigation. According to the preliminary report on the earlier accident, the pilot reported that shortly after takeoff, while conducting a low-altitude reconnaissance of a field, the engine started to lose power. The pilot subsequently initiated a forced landing to the field. The airplane sustained substantial damage, and the pilot was not injured. AIRCRAFT INFORMATIONThe single-seat, low-wing airplane, serial number 5054R, was manufactured in 1975. It was powered by a Pratt & Whitney R-1340-59 reciprocating radial engine, serial number E-142. The overhauled engine was installed on February 24, 2017. According to the operator, the engine had accumulated about 75 hours at the time of the accident. METEOROLOGICAL INFORMATIONThe closest weather reporting facility to the accident site was at Imperial County Airport (KIPL), Imperial, California, about 20 miles southeast of the accident site. At 1053, KIPL reported wind calm, visibility 10 miles, sky clear, temperature 98°F; dew point 60°F, and altimeter setting 29.90 inches of mercury. AIRPORT INFORMATIONThe single-seat, low-wing airplane, serial number 5054R, was manufactured in 1975. It was powered by a Pratt & Whitney R-1340-59 reciprocating radial engine, serial number E-142. The overhauled engine was installed on February 24, 2017. According to the operator, the engine had accumulated about 75 hours at the time of the accident. WRECKAGE AND IMPACT INFORMATIONInvestigators from the National Transportation Safety Board examined the wreckage at the accident scene on August 23, 2017. The first identified point of contact (FIPC) was the engine, which was separated from the airframe and lying flat on the ground oriented propeller side down. A linear ground impact scar extended from both sides of the engine; the two ground scars contained yellow paint fragments and were consistent with wing leading edge imprints. The main wreckage was located about 20 ft north of the FIPC; the fuselage was inverted and oriented on a 263° magnetic heading. Most of the empennage fabric was consumed by fire. The vertical stabilizer remained relatively free of impact damage. Elevator trim tab control continuity was established from the cockpit controls to the trim tab. Rudder control continuity was established from the rudder to the fuselage. The left rudder cable remained intact to the pedal, and the right cable was detached at the bellcrank. Elevator control continuity could not be determined on scene due to impact damage. The outboard and inboard connecting rods on the left aileron remained attached to the left wing. The middle control rods were detached from the aileron. Left aileron control continuity could not be determined due to thermal damage. The right aileron remained relatively free of impact damage and exhibited signatures consistent with thermal damage. Control continuity was established from the right aileron to the fuselage. Right aileron control continuity from the fuselage to the cockpit could not be established due to thermal damage. All three propeller blades remained intact and attached to the propeller hub and was buried about 1ft under dirt and grass. Blades 1 and 2 (numbers arbitrarily assigned) exhibited torsional twisting and aft bending, consistent with engine operation at the time of impact. Blade 3 was relatively free of impact damage. Investigators conducted further examination of the wreckage at Air Transport, Phoenix, Arizona, on October 4 and 5, 2017. The last 4 ft of elevator control tube continuity was established through fractured segments. The fractures were consistent with impact damage. The propeller rotated freely by hand. The forward spark plugs from the Nos. 1, 8, and 9 cylinders were damaged by impact. The forward spark plugs were removed from all cylinders and exhibited a normal wear signature; coloration could not be determined due to oil saturation. Thumb compression was obtained on all cylinders. The carburetor exhibited impact damage. The throttle valve could be moved from stop to stop with difficulty due to the presence of debris from impact. The carburetor case was opened, and no anomalies were observed with the floats and accelerator pump. The fuel filter was removed, and no anomalies were observed. The fuel pump fuel adjustment cover safety wire was separated, and the cap was loose. The fuel pump was disassembled with no debris or anomalies observed; all splines appeared without defect. Testing of the magnetos was not possible due to severe impact damage. The electric flap motor drive screw measured about 1 1/4 inches and about 9 threads were visible. The jackscrew assembly was not located; therefore, the flap setting could not be determined. MEDICAL AND PATHOLOGICAL INFORMATIONThe Imperial County Coroner's Office, El Centro, California, conducted an autopsy of the pilot. The cause of death was attributed to "multiple traumatic injuries." The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicology testing on specimens from the pilot. The testing was negative for ethanol and drugs.