CEN21FA334

The agricultural airplane was operating from a private grass airstrip that was 2,164 ft long and 100 ft wide. The airplane had just been fueled with 225 gallons of fuel and loaded with 635 gallons of chemicals before takeoff. Witnesses stated that the takeoff roll was normal but that, at the departure end of the runway, the airplane struck an embankment, nosed over, and came to rest inverted in a field. The airplane sustained substantial damaged to both wings, the empennage, and fuselage. A postaccident examination of the airplane showed no preaccident mechanical failures or malfunctions that would have precluded normal operation. Based on the airplane’s weight, the field elevation, the field type (turf), and the weather conditions at the time of the accident, the airplane’s planned takeoff ground roll would have been about 2,460 ft, which exceeded the length of the airstrip. Neither witness reported observations consistent with the pilot attempting to abort the takeoff. Thus, the pilot exceeded the airplane’s performance limitations during the takeoff. Toxicology testing detected ethanol at .189 g/dL in the pilot’s blood, .252 g/dL in his vitreous fluid, and .141 g/dL in his urine. Based on available medical evidence, it is likely that the pilot had consumed ethanol. The extent to which measured ethanol levels were affected by postmortem ethanol production is unknown, preventing reliable estimation of the pilot’s blood ethanol level at the time of the crash. Toxicology testing also found gabapentin and doxepin in the pilot’s specimens, both of which can cause impairment, especially when combined with ethanol. The evidence was not sufficient to determine whether doxepin was exerting some effects during the accident flight. However, given the concentration of gabapentin in the pilot’s blood and urine specimens, gabapentin was likely exerting some performance impairing effects, such as sedation and dizziness, which would have been more likely to occur in the presence of ethanol. Thus, the pilot was most likely impaired by the effects of the combined substances in his system.

According to the AT-802/802A takeoff ground roll distance chart, the airplane’s total ground roll distance with a weight of 13,630 pounds, a field elevation of 128 ft above ground level, and a temperature of 27°C would have been 2,050 ft on a paved runway. According to the airframe manufacturer, for a takeoff on a turf, a runway factor of 1.2 [based on Federal Aviation Administration (FAA) Advisory Circular 23-8C, paragraph 23.45(c)] is added to the calculation. Thus, the accident airplane’s takeoff ground roll distance would have been 2,460 ft. On July 25, 2021, about 0745 central daylight time, an Air Tractor 802 airplane, N363BG, was substantially damaged when it was involved in an accident near Benoit, Mississippi. The commercial pilot sustained fatal injuries. The airplane was operated under Title 14 Code of Federal Regulations Part 137 as an aerial application flight. The intent of the flight was to apply product to a bean field located about 3.5 miles southwest of Benoit, Mississippi. According to the operator, the airplane had 225 gallons of Jet A fuel and 635 gallons of product before takeoff. The airplane was operating from a private grass strip that was 2,164 ft long and 100 ft wide that was oriented on a magnetic heading of about 230°. Witnesses stated that they observed a normal takeoff roll but that, at the departure end of the runway, the airplane struck an embankment, nosed over, and came to rest inverted in the field. The Bolivar County, Mississippi, Medical Examiner performed an autopsy of the pilot. His cause of death was multiple traumatic head and neck injuries. The autopsy identified no significant natural disease. Toxicology testing by the FAA Forensic Sciences Laboratory detected .189 g/dL of ethanol in blood specimens, .252 g/dL of ethanol in vitreous fluid specimens, and .141 g/dL of ethanol in urine specimens. Ethanol is a type of alcohol that, if consumed in beer, wine, and liquor, can impair judgment, psychomotor performance, cognition, and vigilance. Ethanol, even in small amounts, can impair performance, and the number and severity of pilot errors tend to increase with increased blood ethanol levels. FAA regulation imposes strict limits on flying after consuming ethanol, including prohibiting the piloting of civil aircraft with a blood ethanol level of 0.04 g/dL or greater. The following prescription medications were also found in the pilot’s heart and urine specimens: gabapentin, doxepin (and its metabolite nordoxepin), rosuvastatin, triamterene, amlodipine, fexofenadine (and its metabolite azacyclonol), and carvedilol. The nonprescription medications acetaminophen and ibuprofen were also detected. Gabapentin is used to treat nerve pain and certain types of seizures. Gabapentin can cause sedation and dizziness and can impair coordination and performance of tasks such as driving and operating heavy machinery. Gabapentin typically carries a warning that the drug may interact with alcohol or other sedatingmedications to worsen sleepiness and dizziness. Doxepin is an antidepressant medication that can have sedating effects and cause psychomotor impairment. Doxepin typically carries a warning that effects of alcohol or other sedating medications may be heightened by the drug. The FAA considers both gabapentin and doxepin to be “Do Not Issue/Do Not Fly” medications. Regular use of either drug for any reason is disqualifying for pilot medical certification. The pilot’s last aviation medical examination was on December 18, 2020. At that time, he reported no medication use and no active medical conditions. He was issued a second-class medical certificate limited by a requirement to wear lenses for distant vision and have glasses for near vision. The airplane was located in a soybean field southwest of the airstrip. The airplane came to rest inverted on its nose, cockpit, vertical stabilizer, and rudder. The airplane’s forward fuselage, cowling, and firewall were crushed aft and bent upward. The forward cockpit was crushed inward and aft. The windscreen and cockpit windows were broken and fragmented. The tops of the vertical stabilizer and rudder were bent and broken aft. The left wing was crushed aft from the tip inboard about 5 ft. The engine and propeller were separated from the airplane and came to rest along a 150 ft path from the initial impact point to the location where the airplane’s main wreckage came to rest. The engine was broken into two sections, the reduction gearbox/exhaust section and the engine power module. The upstream side of the first stage power turbine vane baffle exhibited circumferential rubbing and deformation. The downstream side of the second stage power turbine vane ring showed circumferential rubbing on the outer shroud. The second stage power turbine disk showed that one-fourth of the blades separated just above the blade platform. The remaining blades were fractured in the airfoil at roughly the same height. The propeller was fractured at the flange. All five propeller blades showed bending and twisting toward high pitch. Two of the blades showed S-bending. Four of the five blades showed chordwise rotational abrasions on the back of the blades. No preaccident mechanical failures or malfunctions were found that would have precluded normal operation of the airplane.