CEN22FA053

A loss of lateral control during a hover that resulted in an impact with terrain. Based on the available evidence, the reason for the loss of lateral control could not be determined.

Prior to the flight, the pilot, who is not a mechanic, installed the flight controls at the helicopter’s left seat position. The pilot and passenger, who was in the right seat and held a student pilot certificate, departed from the pilot’s property for a local area flight. The pilot was demonstrating how he performed low-level aerial application maneuvers to the passenger. During a pass to the east, the two occupants both observed a coyote in a large field. The pilot performed a right pedal turn to get a better look at the coyote. The pilot maneuvered the helicopter to an out-of-ground effect hover over the tall grass, facing to the south, about 40 ft agl, and the two occupants were looking at the coyote. The helicopter then immediately began an uncommanded left roll. The passenger couldn’t tell what the cyclic positions were (such as if they both went to the left or if just one went to the left) during the uncommanded left roll. The passenger reported the accident sequence happened “very fast” and that the pilot was on the flight controls for the entire flight. The helicopter did not spin, there were no vibrations emitted from the helicopter, and no alarms or warning lights came on during this period. The helicopter impacted a grass field just prior to a barbed wire fence and a postimpact fire ensued. Postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation; however, the helicopter was destroyed by the postimpact fire. Detailed examination of the flight control system, including determining flight control continuity, could not be established due to the impact and thermal damage. Postaccident scanning and examination of the three hydraulic servo actuators did not reveal any mechanical malfunctions or failures that would result in a cyclic hard over sequence. Based on autopsy findings, the pilot had severe stenosis of two coronary arteries. However, there was no evidence of sudden incapacitation, and the passenger reported that the pilot was acting fine the entire flight. Thus, the pilot’s cardiovascular medical condition was not a factor in this accident. The drug identified on the pilot’s toxicology results was the non-impairing pain reliever acetaminophen, thus the pilot’s medication use was not a factor in this accident. The passenger had reported no medical conditions that would be a factor in this accident. Toxicology testing detected no psychoactive compounds from cannabis in his blood but detected tetrahydrocannabinol (THC) and its psychoactive metabolite 11hydroxy-delta-9-THC (11-OH-THC) in his urine. THC’s inactive metabolite, carboxy-delta-9- tetrahydrocannabinol (THC-COOH), was detected in his blood and urine, but this compound can be found long after using cannabis. Thus, it is unlikely that the passenger’s use of cannabis contributed to the accident. At the time of the loss of lateral control, the pilot and passenger were visually focused outside of the helicopter. With the unexpected and rapid onset of the uncommanded left roll as described by the passenger, there would have been minimal time for the flying pilot to assess and initiate corrective actions. Based on the available evidence, the reason for the loss of lateral control during a hover could not be determined.

The passenger reported the local weather conditions for the flight were no wind, no turbulence, and clear visibility. A review of meteorological data indicated a light southerly wind below 2,000 ft agl, no indication of turbulence or low-level wind shear, or any other outflows or wind shifts. A pilot report indicated flight visibility of 10 miles. There were no inflight weather advisories over the region during the flight. Astronomical conditions indicated the accident occurred before sunset with a low sun elevation present. A review of the meteorological data surrounding the time and location of the accident did not reveal any meteorological areas of concern. The estimated density altitude for the accident site was 931 ft above msl. Pilot At his most recent FAA medical examination, he reported no medications or medical conditions. According to the autopsy report from the Office of the Medical Examiner, Oklahoma City, Oklahoma, the cause of death of the pilot was multiple blunt force injuries and the manner of death was accident. The medical examiner reported the pilot had 90% stenosis of his left anterior descending and right coronary arteries. Toxicological testing performed by the FAA’s Forensic Sciences Laboratory identified the non-sedating pain reliever acetaminophen (commonly marketed as Tylenol) in the pilot’s femoral blood and urine. Passenger At his most recent FAA medical examination, he reported no medications or medical conditions. Toxicology testing performed by the FAA Forensic Sciences laboratory detected the primary psychoactive compound of cannabis, THC, in the passenger’s urine at 1.7 nanograms per milliliter (ng/mL); THC was not detected in his blood. THC’s psychoactive metabolite 11-OH-THC was detected but not quantified in his urine but was not detected in his blood. THC’s inactive metabolite THC-COOH was detected in the passenger’s hospital admission blood at 23.4 ng/mL and in his urine at 84.1 ng/mL. The helicopter was certificated by the FAA in both the standard and restricted airworthiness categories. According to FAA records, the pilot purchased the helicopter in November 2013. According to the pilot’s girlfriend, she flew with the pilot in the helicopter about 1.5 weeks prior to the accident. The pilot took her on an aerial application flight in the local area to spray several crop fields and nothing abnormal was noticed with the helicopter. The girlfriend reported that the pilot was the only one who would install and remove the copilot cyclic control in the helicopter. The pilot would install the copilot cyclic if he was going to fly with his son and then the pilot would later remove it. The helicopter was modified with a Simplex 4900 aerial application spray system per a FAA-approved supplemental type certificate. At the time of the accident, the helicopter did not have the spray booms installed. Per FAA records, the helicopter was equipped with a Satloc unit (unknown model) and a Shadin Fuel Flow Indicator unit (unknown model); however, the Satloc was destroyed and the Shadin Fuel Flow Indicator unit was not identified in the wreckage. The helicopter was not equipped with a crash-resistant fuel system, nor was it required to be. An emergency locator transmitter was not identified in the wreckage and the passenger reported he was unsure if one was installed in the helicopter. The airframe and engine maintenance records for the helicopter were not available for review. Pilot The pilot, who owned the accident helicopter, worked full time as a helicopter air ambulance pilot. The pilot also worked part time as a 14 CFR Part 137 aerial application pilot (as the sole pilot in the business he owned) and as a rancher. The pilot’s helicopter air ambulance company records were available for review; however, the pilot’s personal logbook was not available for review. According to Federal Aviation Administration (FAA) records, the pilot did not hold a mechanic certificate. Passenger/Student Pilot The passenger was enrolled in a university aviation program and was learning to fly helicopters. On November 28, 2021, about 1658 central standard time, a Bell 206B helicopter, N59600, was destroyed when it was involved in an accident near Perry, Oklahoma. The commercial pilot sustained fatal injuries and the passenger, who held a student pilot certificate, sustained serious injuries. The helicopter was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. According to the passenger, who is the pilot’s son, the pilot preflighted the helicopter at 1530. The helicopter was kept on the pilot’s property in a barn. Nothing abnormal was noticed during the preflight. During the preflight, the pilot installed the flight controls for the left seat position. For the flight, both front doors were installed and neither occupant did any filming during the flight. The pilot, in the left seat, had on a surplus US Army (Gentex) SPH-4 helicopter flight helmet, but the flight helmet did not have a tinted visor and he did not have on sunglasses. The passenger, in the right seat, had on a headset, and he did not have on sunglasses. The helicopter departed from the pilot’s property about 1600 with about 50 gallons of fuel onboard, and when the accident occurred there was about 25 gallons of fuel onboard. After departing from the property, the helicopter flew to the Perry Municipal Airport (F22), Perry, Oklahoma. The pilot flew three traffic pattern flights. After the three traffic pattern circuits, the helicopter departed the airport and flew to the west of I-35. According to the passenger, everything appeared normal with the helicopter up to this point. The pilot flew to the west of I-35 over ranch property to demonstrate how he performed his 14 CFR 137 low-level aerial application flights in the helicopter. The passenger reported that the setting sun was in both of their eyes during this timeframe. The pilot performed several low-level east to west maneuvers and he was demonstrating the use of the Satloc aerial application navigation system to the passenger. During these maneuvers, the helicopter was about 15 ft above ground level (agl) and was traveling about 60 kts airspeed. During a pass to the east, the two occupants both observed a coyote in a large field. The coyote was in tall grass, just to the south of a barbed wire fence near where the helicopter came to rest. The pilot performed a right pedal turn to get a better look at the coyote. The pilot maneuvered the helicopter to an out-of-ground effect hover over the tall grass, facing to the south, about 40 ft agl. Both the pilot and passenger were looking at the coyote when the helicopter began an uncommanded left roll. The passenger couldn’t tell what the cyclic positions were (such as if they both went to the left or if just one went to the left) during the uncommanded left roll. The passenger reported the accident sequence happened “very fast,” the pilot was on the flight controls for the entire flight, and that the passenger was not operating the flight controls during the accident sequence. The pilot did not announce anything during this time regarding what he thought was going on with the helicopter. The helicopter did not spin, and the passenger did not recall the main rotor blade striking the ground before the helicopter impacted the terrain. There were no vibrations emitted from the helicopter and no alarms or warning lights came on during this period. The helicopter impacted a grass field just south of a barbed wire fence. The grass around the helicopter instantly caught on fire after the impact. The passenger was able to extract himself and the deceased pilot away from the wreckage. About 5 minutes later, the wreckage caught on fire and was destroyed. The passenger then contacted first responders from his cellular phone who then arrived shortly after. There were no known witnesses who observed the acci