CEN25FA281

The accident occurred during the first application flight of the day while the pilot was applying pesticide to a sugar cane field. He departed from a temporary operating area about one-third mile from the field to be sprayed. According to on-board position data, about one minute later, the helicopter was aligned with the spray field, and the spray system was on. At that time, the helicopter was at an altitude of about 59 ft mean sea level (msl) and traveling about 49 miles per hour. The final Ag-Nav data point was recorded at 0653:42 when the helicopter was about 0.50 nm from the power lines and at an altitude of about 43 ft msl. The sugar cane crop was about 6 to 8 ft high and a tree line bordered the west edge of the field. A set of powerlines was located about 180 ft from the north edge of the field being sprayed. The lines consisted of three transmission and two static lines. The static lines were about 85 ft above ground level (agl) at the supporting H-frames. The south static line was broken during the accident sequence. The operator noted that the transmission line was marked and included in the geospatial mapping data provided for the flight. The fuselage came to rest about 60 ft north of the severed static line. The right landing skid forward of the attachment strut was separated and located about 70 ft south the static line. The upper surface of the separated skid exhibited repetitive abrasion marks consistent with contact to the static line. The outboard portions of both main rotor blades had separated and were located within the debris field. Both blade leading edges exhibited repetitive abrasion marks consistent with contact to a powerline. The tailboom was separated at the aft fuselage and fragmented. The tail rotor blades and transmission were intact, and the tail rotor gear box rotated freely by hand. Examination of the flight control system did not reveal any anomalies consistent with a preimpact failure or malfunction. The engine did not exhibit any anomalies consistent with a preimpact loss of engine power. Engine drive train continuity was confirmed. Rotational witness marks were present on both the main drive (power output) shaft, as well as the tail rotor drive shaft consistent with engine operation at impact. The investigation revealed no preimpact anomalies with respect to the helicopter. The forward portion of the right landing skid contacted the static line causing it to separate from the airframe. Secondary contact to the main rotor blades and the subsequent separation of both blades resulted in the loss of control of the helicopter. The pilot reported a history of diabetes. However, the A1c noted in the toxicology report indicated good long-term control, and the vitreous glucose indicated a low probability of major metabolic disturbance from extreme high blood sugar. However, other diabetes effects such as fatigue or blurry vision could not be excluded based on available medical evidence. The pilot had conductedagricultural application operations for many years and was familiar with the specific field being sprayed. Additionally, the transmission line was marked and included in the mapping data provided for the flight. Helicopter position data did not cover the final portion of the flight due to the data buffering aspects of the system architecture. This prevented a detailed determination of the flight path as the helicopter approached the powerlines. Based on the available information, the pilot slightly misjudged the helicopter flight path which resulted in contact of the right landing skid to the static line and, ultimately, loss of control of the helicopter. The exact reason for that misjudgment by the seasoned agricultural pilot could not be determined.

The operator noted that the transmission line was marked and included in the geospatial mapping data provided for the flight. The manufacturer of the AgNav unit stated that the unit will write 20 data records into volatile memory (buffer) before that data is written to the non-volatile memory (hard drive). When electrical power is interrupted abruptly, such as in an accident sequence, the data being held in the volatile memory will be lost. On July 23, 2025, about 0635 central daylight time, a Bell Helicopter 206L-1, N2611, was destroyed when it was involved in an accident near Thibodaux, Louisiana. The pilot was fatally injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 137 agricultural application flight. The operator reported that the pilot and ground support crew relocated the helicopter from the operator’s base in Abbeville, Louisiana, to Thibodaux on the afternoon before the accident. According to ADS-B data, the pilot landed about 1803. No ADS-B data was recorded for the helicopter on the day of the accident. The accident occurred during the first application flight of the day while the pilot was applying pesticide to a sugar cane field. The operator noted that on the day of the accident, the pilot and ground crew met about 0530. Data recovered from an Ag-Nav unit onboard the helicopter revealed that the pilot departed from the overnight location in Thibodaux about 0629. The pilot flew to a temporary operating area which was about 0.35 nm south of the field to be sprayed. At 0634:43, the pilot departed from the temporary operating area and proceeded to the field to be sprayed. At 0635:40, the helicopter was aligned with the spray field, and the spray system was on. At that time, the helicopter altitude was about 59 ft mean sea level and it was traveling about 49 miles per hour. The final Ag-Nav data point was recorded at 0653:42. At that time, the helicopter was about 0.50 nm from the power lines and at an altitude of about 43 ft. No additional position data was available to the investigation. The spray field was oriented northeast-southwest (030° - 210°), and the sugar cane crop was about 6 to 8 ft high. A tree line bordered the west edge of the field. The fields immediately east, north, and northeast of the field being sprayed were fallow. The helicopter impacted the fallow field immediately northeast of the spray field. A set of powerlines was located about 180 ft from the north edge of the field being sprayed. The lines consisted of three transmission and two static lines. The static lines were about 85 ft above ground level (agl) at the supporting H-frames. The south static line was broken during the accident sequence. The Jefferson Parish Forensic Center (Harvey, Louisiana) performed an autopsy of the pilot. The pilot’s death was attributed to blunt force injuries sustained in the accident. Toxicology testing performed at the FAA Forensic Sciences Laboratory found no carboxyhemoglobin, ethanol, ordrugs of abuse. Glucose (131 mg/dL) was detected in urine. No glucose was detected in vitreous. The pilot’s hemoglobin A1c was 6.3%. Salicylic acid (aspirin) was detected in urine. Metformin was detected in blood and urine. Metformin is a prescription oral medication commonly used for blood sugar control in diabetes. It is not typically impairing. The pilot reported a medical history of diabetes and use of the prescription diabetes medications metformin and semaglutide. (The FAA toxicology testing does not test for semaglutide.) The 67-year-old male pilot’s last aviation medical examination was February 25, 2025. He was issued a second-class medical certificate which was not valid for any class after February 28, 2026. His first Authorization for Special Issuance for diabetes requiring medication had been granted in 2003. His most recent authorization was granted June 30, 2025. The pilot completed biennial wire strike prevention training (Flying in the Wire Environment) on February 23, 2024, and according to the operator, had flown the specific treatment site about 1 to 2 times per year for several years. Overall, the pilot had over 43 years of aerial application experience in Louisiana, specifically in sugarcane operations. The fuselage came to rest about 60 ft north of the south static line and exhibited extensive crushing damage consistent with impact. The right landing skid forward of the attachment strut was separated and located about 70 ft south the static line. The upper surface of the separated skid exhibited repetitive abrasion marks consistent with contact to a powerline, and the fracture surface appeared consistent with an overstress failure. The engine and main rotor transmission remained securely attached to the airframe. The main rotor mast was fractured at the transmission housing consistent with overstress. The separated portion of the mast with the rotor hub and inboard segments of the main rotor blades attached was lying adjacent to the fuselage. The outboard segments of both main rotor blades with the blade tips intact were located about 50 ft from the fuselage. The tailboom was separated at the aft fuselage and fragmented. The aft 6-foot section was positioned about 110 ft from the fuselage. The tail rotor blades and transmission were intact, and the tail rotor gear box rotated freely by hand. The tail rotor drive shaft segments had separated consistent with fragmentation of the tail boom. The pilot (right side) cyclic and collective control continuity were confirmed from the control sticks to the servo actuators. The left control tube from the actuator to the fuselage upper deck bellcrank was separated consistent with overstress. The center and right control tubes were intact, as were the pitch change links from the bellcrank to the lower portion of the swash plate. The co-pilot (left side) cyclic and collective controls were not installed. The pilot (right side) anti-torque pedal continuity exhibited multiple separationsconsistent with impact. The copilot (left side) pedals were present and properly locked out from operation. The engine remained within the engine compartment but exhibited extensive impact damage. Continuity was confirmed from the compressor through the accessory gearbox to the starter/generator, as well as to the gas generator turbine. The power turbine rotated freely by hand and exhibited no evidence of operational damage or failure. Rotation of the power turbine resulted in corresponding rotation of the main and tail rotor drive shafts. Drive train continuity through the main rotor transmission to the main rotor mast was confirmed. Rotational witness marks were present on both the main drive (power output) shaft, as well as the tail rotor drive shaft. The steel shaft had disengaged from the tail rotor drive train consistent with the accident sequence. The steel shaft left evidence on the aft firewall of continued rotation after disengagement. The oil cooler fan exhibited extensive rotational damage consistent with engine operation at impact. Borescope examination of the combustion section (via the fuel spray nozzle port) revealed no evidence of abnormal combustion or operational damage of the combustion liner.