Greenwood, MS, USA
N581LA
AIR TRACTOR INC AT-802
The commercial pilot was conducting aerial application operations on two fields with which he was familiar. He completed the treatment of one field, which comprised three separate flights, then returned to the operator's facility, where the airplane was fueled and chemicals were loaded for the second field. After takeoff, the airplane proceeded to the field, where one witness noticed the airplane making spray passes from east to west, then heard what he described as two nearly simultaneous, "loud/hard" sounds similar to that of the sound of dynamite. A second witness reported hearing the sound of the impact; he did not hear any unusual sound from the airplane. There were no witnesses to the impact. The airplane's right wing impacted a tree about 40 ft above ground level while the airplane was flying in a left bank of less than 30°. The airplane then impacted the ground inverted about 515 ft from the tree. Examination of the engine, propeller, and flight controls revealed no evidence of preimpact failure or malfunction. Toxicology and autopsy of the pilot revealed no evidence of impairment or incapacitation. Based on the available information, the reason for the impact with the tree could not be determined.
HISTORY OF FLIGHTOn February 26, 2018, about 1718 central standard time, an Air Tractor Inc. AT-802A, N581LA, was substantially damaged when it impacted trees and terrain near Greenwood, Mississippi. The commercial pilot was fatally injured. The airplane was owned by Ag Concepts Inc. and was being operated as a Title 14 Code of Federal Regulations Part 137 aerial application flight. Visual meteorological conditions prevailed at the time of the accident and no flight plan was filed. The accident flight originated sometime after 1706 from the operator's airstrip located in Morgan City, Mississippi. According to the mixer/loader, the pilot was scheduled to conduct applications to two fields that day, each field requiring three loads of chemicals. Data downloaded from the onboard GPS receiver showed three flights and multiple spray passes to the first spray field, located about 3 nautical miles east-northeast from the operator's airstrip. The flights began at 1548 and ended at 1701 when the pilot returned to the operator's airstrip. The accident flight was not recorded. The loader indicated that, before the pilot departed on the accident flight, both fuel quantity gauges indicated 1/2 capacity. He stated that the pilot had not completed a survey of the application field before this flight, but he had previously sprayed the field "…hundreds of times." According to a witness about 1 nautical mile east-southeast of the accident site, while looking to the west through an opening in trees, he noticed an airplane making passes from east to west. He then heard what he described as two nearly simultaneous, "loud/hard" sounds similar to the sound of dynamite. He stated that the second sound was louder than the first. He also equated the sound to what would be heard when "blowing up a beaver dam." A pilot-rated witness located about 1.7 nautical miles west-southwest of the accident site reported that, while walking on a road, he heard an airplane flying from what he thought was the Morgan City area. He reported that the airplane flew near him and then in an easterly direction, consistent with a spray application pass. He then heard the sound of the impact. He indicated that when he saw the airplane, it was flying between 200 and 300 ft, and he did not hear any unusual sound from the airplane. There were no known eyewitnesses to the impact sequence. PERSONNEL INFORMATIONThe pilot, age 36, held an airline transport pilot certificate with airplane single- and multi-engine land ratings and commercial privileges for airplane single-engine sea. He also held a flight instructor certificate with airplane single- and multi-engine and instrument airplane ratings. He held a first class Federal Aviation Administration (FAA) medical certificate with no limitations, issued August 21, 2017. On the application for the medical certificate, he reported 12,500 total hours of flight experience, and 500 hours in the previous 6 months. The pilot was hired by the operator as a contract pilot in February 2013 and remained in either a part-time or full-time capacity since that date, becoming the company's chief pilot in early 2015. According to company records dated January 22, 2016, the pilot indicated 500 hours of flight experience in the Air Tractor AT-802A airplane, all in the previous 12 months. The manager and loader of Ag Concepts, who interacted with the pilot earlier on the day of the accident, reported that the pilot had no health issues and that he was happy to be flying. The loader noted that the pilot was wearing his helmet and the shoulder harness before departing on the accident flight. AIRCRAFT INFORMATIONThe single-seat, low-wing airplane, serial number 802A-0581, was manufactured in 2015. It was powered by a Pratt & Whitney Canada PT6A-65AG engine, rated at 1,220 shaft horsepower and was equipped with a 5-blade, reversing, feathering, Hartzell HC-B5MP-3F/M11276NS propeller. Review of the maintenance records revealed that the airplane's last inspection was an annual inspection on January 26, 2018. METEOROLOGICAL INFORMATIONAt 1653, a surface weather observation taken at Greenwood-Leflore Airport, located about 9 nm east-southeast of the accident site, reported wind from 020° at 5 knots, 10 miles visibility, temperature 19°C, dew point 6°C, and an altimeter setting 30.24 inches of mercury. A witness near the accident site reported that the wind was from the northwest at 6 mph. According to the US Naval Laboratory, the sunset occurred at 1755. According to the National Oceanic and Atmospheric Administration solar calculator, based on the accident site coordinates and the accident date and time, the sun's azimuth was about 246° true north and the elevation was about 19°. AIRPORT INFORMATIONThe single-seat, low-wing airplane, serial number 802A-0581, was manufactured in 2015. It was powered by a Pratt & Whitney Canada PT6A-65AG engine, rated at 1,220 shaft horsepower and was equipped with a 5-blade, reversing, feathering, Hartzell HC-B5MP-3F/M11276NS propeller. Review of the maintenance records revealed that the airplane's last inspection was an annual inspection on January 26, 2018. WRECKAGE AND IMPACT INFORMATIONExamination of the accident site area revealed damage to a tree east of the accident site. The tree was located north of the northeastern edge of the intended spray fields. The tree damage was about 40 ft above ground level and was consistent with the airplane being in a left bank of less than 30° at the time of impact. A 17-ft-long piece of tree limb with 2-inch diameter branches was found in a ditch beneath the tree. The light-emitting diode (LED) portion of a strobe light, damaged tree limbs of varying diameters, navigation and strobe light lens, and the housing of an LED navigation light were found on the ground east of the tree, while three sections of the right spray boom, right wingtip, sheared rivets, wingtip fiberglass with blue-colored primer, cut and broken tree limbs, and a brake line strap were found on the ground west of the tree. The largest tree limb was about 4 inches in diameter. An impact crater with sections of the overhead turn windows, light bar, hopper lid, windshield frame, 2 propeller blades, and hopper auger was located about 515 ft west of the tree, while a continuous ground scar measuring about 176 ft in length oriented on a magnetic heading of 290° was noted between the impact crater and the inverted airplane, which came to rest on a magnetic heading of 332°. The left wingtip was located on the right side of the debris path. The ailerons, elevators, and rudder remained attached or were found in close proximity to the main wreckage. There was no evidence of preimpact failure or malfunction for any of the primary or secondary flight controls. Both wing flaps were symmetrically retracted. The right horizontal aft spar attachment was fractured in tension overload. The spray system components on the bottom of the fuselage remained attached or partially attached. Examination of the empennage revealed that the vertical stabilizer and upper portion of the rudder were displaced aft. The upper forward portion of the vertical stabilizer was crushed aft and the rudder was displaced down and compressed vertically. Both wings remained attached to the fuselage and to the opposite wing through the center wing splice connection and exhibited impact damage. The right wing exhibited a semi-circular shaped depression in the leading edge consistent with tree contact. All of the boom hangers of both wings were present on the bottom of each wing. The aileron flight control surfaces of both wings were examined for evidence of jamming associated with contact by the tree. Although denting of the leading edge of the right aileron was noted, there was no evidence of jamming of either aileron. Examination of the cockpit following recovery of the airplane revealed that the upper portion was fragmented. The dump handle was in the aft and locked position. The control stick was damaged but not fractured. All 5 restraint straps and the airbag hoses were cut. The instrument panel was separated from the airplane; several instruments were separated from the panel. The engine power lever was near the idle position, the propeller lever was in the feather position, the fuel condition lever was in the RUN position, and the rudder trim was in the full-nose-right position. The elevator trim control was in the neutral or "takeoff" position. Both spray booms were fragmented into multiple pieces. Examination of portions of the right spray boom revealed that one fractured section exhibited a 2-inch diameter contact mark on the leading edge consistent with tree contact. The hopper door was closed and locked. The engine was separated from the airframe and found resting near the main wreckage. The propeller and reduction gearbox were separated, and only one propeller blade remained secured to the propeller hub. All propeller blades were accounted for at the accident site. Examination of the reduction gearbox revealed all webs of the second stage carrier were fractured, consistent with overstress due to high torsion loads; no evidence of pre-existing cracks were noted in the fracture surfaces. Four propeller blades exhibited varying degrees of aft bending, while one propeller blade exhibited a slight forward bend. Examination of the engine and propeller revealed no evidence of preimpact failure or malfunction. MEDICAL AND PATHOLOGICAL INFORMATIONA postmortem examination of the pilot was performed by the Office of the State Medical Examiner, Pearl, Mississippi. The cause of death was reported as multiple blunt trauma. Toxicology testing performed at the FAA Forensic Sciences Laboratory detected no carbon monoxide, volatiles, or tested-for drugs; testing for cyanide was not performed. TESTS AND RESEARCHBased on previous roll rate testing of a AT-802 airplane by Air Tractor, at 9,300 pounds with an engine torque of 2,300 ft-lbs, the propeller at 1,650 rpm, and the airplane flying at 90 mph, the roll rate was determined to be 29° per second. The AT-802 shares the same wings and ailerons as the AT-802A. Calculations to determine roll rate based on varying speeds other than 90 mph were performed by personnel from Air Tractor. The results indicated that at 170, 180, and 190 mph, the roll rates were 103°, 116°, and 129° per second, respectively. The calculations assumed a steady state maneuver and could not predict what the roll rate may be for an aggressive maneuver such as a snap roll. Correlation of the impact creases on the inboard and outboard ends of both ailerons to an exemplar AT-802A airplane was performed by a representative of Air Tractor. The creases on the inboard and outboard ends of the right aileron were consistent with the aileron deflected up 14.8° and 11.4° respectively, while the creases on the inboard and outboard ends of the left aileron were consistent with the aileron deflected 3.7° up and 11.3° down, respectively. The report indicated that simultaneous upward and downward deflection of the left aileron was not possible, and an 11.3° down deflection of the left aileron corresponded to 12.5° up deflection of the right aileron. According to Air Tractor, the total design travel for each aileron was 17° up and 13° down.
The pilot's failure to maintain clearance from a tree for reasons that could not be determined based on the available evidence.
Source: NTSB Aviation Accident Database
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