NTSB Factual Report

HISTORY OF THE FLIGHT

On September 16, 2016, about 0915 eastern daylight time, a Cessna A188, N3547Q, was destroyed when it impacted terrain while maneuvering near Alapaha, Georgia. The commercial pilot was fatally injured. The airplane was registered to and operated by the pilot 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, which originated from Berrien County Airport (4J2), Nashville, Georgia, about 0855.

According to a ground assistant who routinely supported the pilot during agricultural operations, the pilot planned to complete a total of three aerial application flights on the day of the accident. He reported that the pilot departed on the first flight of the day at 0715 and returned about 1 hour 15 minutes later. The assistant reported that the pilot stated, "everything seems good," and they began preparations for the second flight.

The assistant loaded about 150 to 160 gallons of chemical and water mix into the airplane's hopper, and the pilot "topped off" the single fuel tank from his personal trailer-based fuel tank. The assistant reported that the pilot intended to spray a 13-acre cotton field, which was about 14 miles north of the departure airport, a flight time of 8 to 9 minutes. He further reported that the pilot also intended to spray a 100-acre field during the flight, and that the pilot liked to spray the "larger fields first, to lighten his load" before spraying smaller fields. He added that he observed the pilot put on his shoulder harness and flight helmet and depart at 0855.

Two witnesses, located about 1/4 to 1/2 mile from the 13-acre cotton field, heard an airplane "flying back and forth" about 0915. Subsequently, the engine noise went silent, and then they heard an impact. One witness stated that the sound of impact was "5 to 10 seconds" after the engine noise went silent. Neither witness saw the airplane flying.

PERSONNEL INFORMATION

According to Federal Aviation Administration (FAA) airmen records, the pilot held a commercial pilot certificate with a rating for airplane single-engine land. His most recent second-class medical certificate was issued in June 2016 with no limitations. The pilot did not report his flight time on his most recent medical certificate application.

Review of the pilot's logbook revealed entries between June 5, 2013, and June 26, 2016, which indicated a total flight experience of 450 hours of which 410 hours were as pilot in command and 125 hours were in the accident airplane make and model. According to the pilot's ground assistant, the pilot had performed multiple aerial application flights in the accident airplane in the 2-week period preceding the accident, which were not recorded in the logbook. The logbook showed that the pilot's most recent flight review was on February 23, 2015.

AIRCRAFT INFORMATION

According to FAA airworthiness records, the single-seat, low-wing, fixed-landing-gear airplane was manufactured in 1969 and was registered to the pilot in June 2013. It was equipped with a 300-horsepower Continental Motors IO-520-D (9A) engine and a two-blade McCauley controllable-pitch propeller.

According to airframe and engine logbooks, the most recent annual and 100-hour inspections were completed in May 2016 at a recorded tachometer time of 2,741.9 hours and 642.1 hours since engine major overhaul. Review of the logbooks indicated that between April 2013 and May 2016 a total of 23 hours were accumulated on the tachometer.

Weight and Balance

The airplane flight manual (AFM) stated that the airplane's maximum gross weight for takeoff in the restricted category was 4,000 lbs, which was 700 lbs above the normal category maximum gross weight (3,300 lbs). According to maintenance records, in June 2014, the airplane was moved from the normal category to the restricted category.

A weight calculation was completed based upon the pilot's last reported weight on his medical certificate (176 lbs), full fuel (37 gallons), the reported chemical and water mix load (155 gallons), and an estimated empty weight for the airplane of 1,910 lbs. (The airplane's actual empty weight was not found.) The calculation revealed that the airplane's takeoff weight was about 3,601 lbs, which was within the restricted category limit.

Airplane Fuel System

According to the AFM, fuel from the standard fuselage fuel tank system was supplied to the engine from a 37-gallon aluminum tank located just aft of the engine compartment firewall. Fuel flowed from the tank to a shutoff valve beneath the tank. When the shutoff valve was open and the mixture control was in the rich position with the engine running, fuel was drawn through a check valve in the auxiliary fuel pump and through the fuel strainer to the engine-driven fuel pump, where it was pumped into the fuel metering unit. In the metering unit, fuel was regulated by setting the throttle and mixture controls. The metered fuel was then pumped through the fuel distribution valve to the injection nozzles. The remainder of the unmetered fuel was returned to the engine-driven fuel pump where excess fuel and vapor were directed through a return line to the top of the fuel tank.

Restricted Category Flight Characteristics

The AFM stated, in part: "Although the airplane is capable of working at speeds from 85 MPH [miles per hour] to 120 MPH, it is suggested that a speed of 95 MPH to 115 MPH be used for very heavy loads. The use of very low airspeeds in combination with heavy loads is not recommended because it reduces the margin of safety."

The AFM further stated, in part: "The stall characteristics are conventional, and aural warning is provided by a stall warning horn which sounds between 5 and 10 MPH above the stall in all configurations. The stall is also preceded by a mild aerodynamic buffet which increases in intensity as the stall is approached. All controls remain effective throughout the stall." The AFM also stated that, "Intentional spins are prohibited in this airplane. Should an inadvertent spin occur, standard light plane recovery techniques should be used."

METEOROLOGICAL INFORMATION

The weather conditions reported at Henry Tift Myers Airport (TMA), Tifton, Georgia, at 0915, located about 16 miles west of the accident site, included wind 060° at 3 knots, visibility 10 statute miles, sky condition clear, temperature 24°C, and dew point 23°C.

WRECKAGE AND IMPACT INFORMATION

Examination of the accident site revealed that the airplane came to rest upright in an open plowed dirt field, which bordered the cotton field being sprayed, on a heading of about 115° to 120° magnetic. The wreckage path led from broken tree branches (initial impact point) to the main wreckage and was about 100 ft long on a 300° magnetic heading. All major components of the airplane were accounted for at the scene.

The fuselage exhibited impact and fire damage; however, there was no evidence of fire in flight. The left wing remained attached to the fuselage. The right wing was found twisted forward of its normal position; the fuselage was canted to the right just forward of the firewall; and the empennage displayed metal tearing to the right. The separated empennage control surfaces were found under the rear fuselage. The fixed main landing gear assemblies were separated and found in the debris field. Both flaps were found in an extended position. Flight control continuity was confirmed from the flight control surfaces to the burned outer section of the cockpit.

Examination of the cockpit revealed that the throttle control lever was about 1/3 forward from idle. The propeller control lever was found in the full forward position (high rpm). The mixture control was found pulled aft about 1 inch. The fuel shutoff valve was found in the "ON" position. The flap handle was found in a near vertical position past the flaps 20° extended position. The pilot's four-point lever-lock-style buckle was found latched with the shoulder harness buckle ends engaged in the lever lock. The instrument panel was consumed by fire. An agricultural GPS spray guidance system was found mounted in the cockpit; the device sustained fire and impact damage, and no data were recovered.

The engine remained attached to the engine mount, firewall, and control cables and was thermally damaged. Crankshaft continuity was confirmed from the propeller flange to the accessory section of the engine. Thumb compression and suction were observed on all cylinders when the propeller flange was rotated. All spark plugs were examined with no anomalies observed. Each magneto was removed and rotated manually; spark was observed at each individual ignition lead. The engine-driven fuel pump drive coupling was intact, and no anomalies were found when the pump was examined. The oil filter screen was removed from the oil pump housing, and no contaminants were found.

The fuel manifold was examined; the filter screen was clear of debris, and no fuel was present. All fuel injectors were found to be open and without contamination. The fuel strainer was intact and clear of contaminants. The throttle-body metering unit was impact-damaged and separated from its mount. The flexible fuel hose connected to the throttle body unit was severed and fire- and impact-damaged, but the metering unit remained intact. A compacted contaminant was found obstructing the entire fuel filter screen in the metering unit that was further examined by the NTSB Materials Laboratory in Washington, DC, and determined to be dirt that had come in contact with aviation fuel.

The propeller separated from the crankshaft propeller flange and was found in the debris path about 36 ft from the engine. Blade one exhibited a slight rearward bend and chordwise scratching on the outboard section. Blade two exhibited rearward bending, twisting, and chordwise scratching and paint transfer over its entire length.

MEDICAL AND PATHOLOGICAL INFORMATION

The Georgia Bureau of Investigation, Division of Forensic Sciences, Central Regional Lab, Berrien County, Georgia, performed an autopsy of the pilot. The cause of death was thermal and blunt force injuries, and the manner of death was accident.

The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicology testing on samples from the pilot. The testing identified cetirizine, a potentially-impairing antihistamine, in blood and urine, salicylate (aspirin) in urine, and 16% carbon monoxide in blood.

ADDITIONAL INFORMATION

Fuel Source and Fueling Operations

According to the pilot's ground assistant, the pilot had used his own trailer-based 450-gallon fuel tank for flight operations since the fall of 2015. The fuel tank was used for multiple flights on the day before and day of the accident. He further reported that the week before the accident, he and the pilot refueled the tank with 120 gallons of 100LL aviation fuel from the self-service fuel pump at TMA.

The ground assistant reported that two interconnected fuel hoses were attached to the fuel tank. The fuel tank was originally equipped with a 10-ft fuel hose, and the week before the accident, the pilot added a 20-ft extension. The ground assistant further reported that normally during preflight preparation, if fuel had not been pumped for a few days or more through the hose, they would run 1 or 2 gallons of fuel through the hose because of a brown discoloration in the fuel. He added that, after pumping a few gallons, the fuel would return to a "normal blue" 100LL color and then fuel would be added to the airplane.

Three days after the accident, an FAA inspector drained fuel from the pilot's trailer-based fuel tank and reported that the fuel sample was "clean and blue" and that he observed no debris. Additionally, 10 days after the accident, an NTSB investigator observed the pilot's ground assistant pump fuel samples through the 30-ft fuel hose into clear containers. The first 1 to 2 gallons of fuel pumped appeared dark green, but, as the pumping continued, the fuel appeared light blue, consistent with 100LL fuel.

The NTSB Materials Laboratory examined the two fuel hoses from the pilot's trailer-based fuel tank. The fuel hoses were determined to be made of rubber, and both hoses appeared to be completely intact and showed no signs of chemical degradation.

NTSB Probable Cause

The pilot's failure to maintain adequate airspeed while maneuvering at low altitude during aerial application operations, which resulted in the airplane exceeding its critical angle-of-attack and entering an aerodynamic stall and spin.