MIA02GA137 · Cessna 172S

The flight departed about 1300 with a pilot, co-pilot, and observer (law enforcement officer) on-board for a marijuana eradication flight operated by the Civil Air Patrol. The airplane had been operated earlier that day in the morning and afternoon orbiting throughout areas of the county between witness reported altitudes of between 300 and 500 feet agl on the same type of mission by the same pilot. After departure on the accident flight, the flight continued the aerial observation and according to one witness, on the last pass, the airplane was observed in a large clockwise orbit noticeably lower than the 300 to 500 feet agl previously observed. A sputtering noise was heard by one witness, and another stated there was no engine sound at all just before she observed the aircraft depart normal upright flight. From an altitude of about 120 to 150 feet agl, she saw the aircraft simultaneously nose over vertically and commence a right half roll into the terrain. The airplane came to rest inverted in a field containing cotton crops. One EMT who was on-scene within minutes of the accident reported observing a finger sized stream of fuel leaking from the left wing root area; the leakage lasted an estimated 15-20 minutes. Other personnel on scene stated they did not smell a strong odor of fuel after arriving within minutes of the crash. There was no evidence of leakage from the right fuel tank; the header tank was impact damaged. The fuel selector was found positioned to the "both" position. No evidence of preimpact failure or malfunction of the flight controls for roll, pitch, and yaw was noted, and no evidence of preimpact mechanical failure/malfunction of the engine, magnetos, or mechanical fuel pump was noted. The flaps were extended 10 degrees. Bench testing of the impact damaged fuel injection servo as received revealed it flowed greater than specified service limits. The impact damaged mixture control shaft was replaced, the unit was flow tested and found to flow within limits at all ranges above idle. Examination of the flow divider revealed the cover had the same safety wire pattern as the pattern used during manufacturing; bench testing of the unit revealed it operated at 2.0 psi; no contamination was noted following disassembly, and the spring was not failed. Fuel consumption calculations indicate that an estimated 15 gallons of fuel should have been on-board at the time of the accident.

Verbatim NTSB analysis and probable cause from the NTSB dataset