roccoangelella/AeroGraph huggingface dataset:
The purpose of the flight was to longline equipment to firefighters working on the ground. After a normal liftoff, the helicopter was hovering with the longline fully extended as it maneuvered to hook up to the external load. A loud “snap” or “bang” was heard, and one witness described that the helicopter “bucked.” The helicopter subsequently rolled to the right, entered a nose-low descent, and impacted the ground before bursting into flames. A video camera captured the helicopter’s final seconds before impact with the ground. In the video recording, the helicopter is seen hovering about 140 ft above the ground as the pilot maneuvered the helicopter to hook up to the external load. During the maneuver, a loud mechanical noise occurred, and a shudder could be seen radiating through the helicopter’s fuselage, followed by an extreme roll to the right past 90°, and a nose-low descent. As the helicopter continued its descent, the transmission, with the rotor head and blades attached, and the tail boom separated from the helicopter before ground impact. The loud noise and shuddering of the helicopter suggest that a mechanical problem likely preceded the loss of control. The sudden drop in altitude, combined with the forward pitch and right roll, enabled a mast bump condition that bent the rotor mast and caused an imbalance in the rotor system. This imbalance likely overloaded the transmission pylon structure, separating the transmission and main rotor from the rest of the airframe. The following out-of-plane divergence of the main rotor precipitated the tail boom separation.The circumstances of the accident and motion of the helicopter during its descent are similar to the findings of a flight test in which a similar helicopter was subjected to a loss of hydraulic pressure to the main rotor flight control system. Because the factual information available was Page 2 of 9 ANC22FA047limited, in part due to the post-crash fire and a lack of available recorded data, it could not be determined whether a loss of hydraulic pressure occurred during the accident sequence. In addition, there was no evidence of a malfunction in the hydraulic flight control servos or hydraulic pump; therefore, the reason for the loss of control could not be determined. The pilot’s medical records showed a history of cardiovascular conditions that placed him at an increased risk for a sudden cardiac event, including a heart attack or arrhythmia that could cause acute symptoms such as chest pain, shortness of breath, palpitations, or fainting; however, there were no autopsy findings to suggest that any of those occurred, and his most recent cardiologist follow-up showed him to be doing very well, asymptomatic, and tolerating his medications. His recent exercise stress test showed he had above average exercise tolerance for someone his age. Further, a witness reported that the pilot was alert and attempting to retain control of the helicopter as it descended. Therefore, it is unlikely that the pilot’s cardiovascular conditions were a factor in this accident.
The student pilot reported that during landing, the airplane bounced and after it settled back on the runway, veered to the left. He stated that he was unable to maintain directional control and the airplane departed the runway into a ditch, which resulted in substantial damage to the left wing and fuselage. The pilot reported that there were no mechanical malfunctions or anomalies that would have precluded normal operation.
The pilot of the float and wheel-equipped airplane reported that while the airplane was accelerating on the water for takeoff it veered to the right. While attempting to correct for the veer, he noticed a skiff in his departure path, which caused a momentary distraction. Unable to correct for the veer he aborted the takeoff but was unable to avoid an impact with the rocky shoreline, which resulted in substantial damage to the right wing and aileron. The pilot reported that there were no preaccident mechanical malfunctions or anomalies that would have precluded normal operation.
During an aerial application flight, the helicopter impacted power lines that were near the top of the canopy of a mesquite tree grove. The helicopter was destroyed during the impact. No radio or distress calls were heard from the pilot before the collision. Detailed examinations of the flight controls, airframe, and engine did not reveal any preimpact mechanical malfunctions or failures that would have precluded normal operation. Examination of the engine revealed multiple transfer marks and scoring consistent with engine rotation at the time of impact.The pilot's toxicology results indicated that he had used a cannabis product. The precise timing of his cannabis use, and whether he was experiencing impairing effects from that use at the time of the accident, could not be determined from available evidence. Thus, it is unknown whether effects of the pilot's cannabis use contributed to the accident. The pilot's autopsy identified mild coronary artery disease and mild left ventricular hypertrophy of the heart. This heart disease conveyed some increased risk of a sudden impairing or incapacitating cardiac event, such as heart attack or abnormal heartbeat. Based on available medical evidence, it was unlikely that the pilot's mild heart disease contributed to the accident.
The pilot reported that, as the float-equipped airplane accelerated on the water for takeoff, a gust of wind turned the airplane 90° to the left. The left float subsequently impacted a wave and the airplane rolled inverted. The airplane eventually sank and was not recovered. The pilot reported that there were no preaccident mechanical malfunctions or anomalies that would have precluded normal operation.
The pilot of the vintage tailwheel airplane was attempting a takeoff from an uphill 1,550-ft-long turf airstrip, with a 3-knot left-quartering headwind and in an 80° F ambient temperature. The airplane lifted off at the end of the airstrip; however, the right main landing gear and right horizontal stabilizer impacted the top of a 4.5-ft high fence. The airplane then settled into a field on the other side of the fence and during the landing roll, the right main gear impacted a groundhog hole and collapsed.Initial examination of the wreckage revealed substantial damage to the right horizontal stabilizer. The pilot reported that the engine sputtered for about 3 seconds before collision with the fence and additional examination of the engine was planned following recovery of the wreckage from the field; however, the pilot did not respond to subsequent requests regarding the disposition of the engine for examination. He also was unable to produce maintenance and pilot logbooks for examination. Whether an engine anomaly may have contributed to the accident could not be determined. Review of the airplane’s owner’s handbook revealed a published takeoff distance of 625 ft on a hard turf surface. More recent publications listed a takeoff ground roll of 1,050 ft; however, none of the data accounted for performance considerations such as an upsloping turf runway, high ambient temperatures, or distance to clear obstacles.
The pilot reported that during the landing flare the airplane “floated more than I expected.”  After touching down and seeing he did not have much runway remaining, the pilot applied toe braking, and realized he would not be able to stop before the end of the runway. Instead, he elected to turn to the right exiting the runway into a grassy area and subsequently struck a taxiway sign resulting in substantial damage to the fuselage. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.
The pilot was practicing touch and go landings, when on the last final approach, the airplane was a “little slow and low on the glide path” and struck a car passing on the roadway in front of the runway. The main landing gear was separated, and the fuselage was substantially damaged. The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.
The pilot was conducting power-off aerodynamic stall recoveries about 3,000 ft mean sea level (msl) at the time of the accident. The first three stall recoveries were unremarkable. However, before the fourth stall, the airplane’s deceleration rate and pitch attitude were greater than the previous three stall entries. The airplane snapped to the left and rolled inverted. It continued to roll and settled into an upright left spin with a relatively flat nose-down pitch attitude between 10° and 20°. Multiple attempts to recover from the spin were not successful. The airplane made about 6 complete rotations before it impacted the terrain. The airplane sustained substantial damage to both wings, the fuselage, and the empennage.The pilot reported no malfunctions or failures associated with the airplane before the accident. He noted that initiating recovery at the first indication of the stall might have prevented the loss of control.
Witnesses reported that, during takeoff, the airplane became airborne about 1,000 ft down the 5,000-ft-long runway and immediately pitched up to a nose-high attitude with little increase in altitude. The witnesses also reported that the engine ran smoothly during the entire event. As the airplane passed the departure end of the runway, it made a slight right turn, followed by a sharp turn to the left back toward the runway. During the left turn, the nose dropped, and the airplane impacted the ground past the end of the runway in a left-wing-low attitude. Examination of the airplane revealed no evidence of a preexisting mechanical malfunction or failure that would have precluded normal operation. Given the witness statements and the lack of mechanical anomalies, it is likely that the pilot exceeded the airplane’s critical angle of attack while attempting to return to the airport during the initial climb, which resulted in an aerodynamic stall, loss of control, and impact with terrain.
The pilot reported that, following a bounced three-point landing at a remote unimproved airstrip, a gust of wind pushed the airplane toward terrain. He elected to conduct a go-around while maneuvering around various obstacles. The airplane subsequently settled to the ground and impacted a ditch, which resulted in substantial damage to the empennage. The pilot reported no preaccident mechanical failures or malfunctions that would have precluded normal operation and that the accident may have been prevented if he had conducted a low approach before attempting to land followed by a wheel landing.
The pilot reported that he was on an agricultural spray run. He had just performed a 180° turn and, about six feet above ground level (agl), he felt a vibration. He then felt a “snap” and the helicopter began to rotate left. He applied right pedal, entered an autorotation, and attempted to decrease the airspeed. He tried to perform a run-on landing in the 4-ft-tall corn, but upon touchdown, the helicopter rolled up on its nose and the main rotor blades severed the tail boom. A postaccident examination revealed that the KAflex driveshaft was separated and there were several sheared bolts and pieces of the KAflex located underneath the engine.  Subsequent metallurgical examination determined that the failure of the KAflex coupling resulted from fatigue observed in two flex plate segments and an adjacent attachment bolt, indicating these components were the initial points of failure. The fatigue cracking initiated at areas adjacent to wear and material loss. With the fracture of flex plates and bolts, the interconnect and end fitting could rotate, resulting in the assembly failure. One flex plate and bolt exhibited more fatigue, suggesting longer crack propagation and earlier fracture, while thumbnail cracks on a second flex plate indicated incipient propagation when other components failed in overstress.The bolt and flex plate with fatigue features showed severe wear and loss of cross-sectional area, potentially concentrating stress at these locations. Although the investigation could not determine which fractured first, the joint had become loose, likely due to wear over time or inadequate assembly/maintenance. Most of the fractured bolts did not have discernable fracture features, likely lost to post fracture wear and battering. Visual inspections during maintenance might reveal a loose bolt, but fatigue cracks in these components would be more difficult to detect, leading to rapid propagation in rotary aircraft parts.Page 2 of 7 WPR22LA236
The accident flight was intended to teach the flight instructor candidate how to enter, recognize, and recover from an aggravated stall wherein the airplane follows a corkscrew path. Before the accident maneuver, automatic dependent surveillance - broadcast (ADS-B) data revealed that several training maneuvers were performed with extraordinary directional changes greater than 180° or rapid descents in altitude. The rapid changes in altitude and recovery were consistent with stall or spin recovery maneuvers. Although there were no witnesses to the accident, surveillance video footage captured the airplane descending rapidly in a developed spin. Postaccident examination of the airframe and engine revealed that the airplane impacted terrain in a 45° nose-down attitude, with no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation.The operator’s training guidance stated that the minimum altitude to perform spin training was 9,500 ft mean sea level (msl). According to ADS-B data, the accident maneuver was entered about 9,100 ft msl, and the elevation at the wreckage site was 4,590 ft. According to the operator’s flight experience logs, the flight instructor accumulated 2 hours of flight experience learning how to spin the accident airplane. The fight instructors personal flight logs were not provided, and his total flight experience was not determined. According to the operator’s flight experience logs, the flight instructor candidate had no actual flight experience in the accident airplane make and model.The pilot under instruction's toxicology testing detected codeine and morphine in urine at low levels. These results could be explained by codeine use alone, although other potential explanations exist. Regardless, the pilot under instruction had no detectable codeine or Page 2 of 10 WPR22FA227morphine in his blood, which makes it unlikely that codeine or morphine effects contributed to the accident.
The pilot reported that the amphibious airplane’s engine gradually lost partial power shortly after takeoff and he was unable to maintain altitude. He performed a forced landing in a field with the retractable landing gear in the retracted position. After touchdown on the hull, as the airplane slowed, the right wing settled to the ground and the right-wing sponson struck the ground. The airplane incurred substantial damage to the right wing and fuselage during the forced landing.  Postaccident examination of the airplane revealed that the fiberglass fuel tanks of the airplane had debris and deterioration. The resin used in construction of the fuel tanks was not compatible with automotive gasoline. The pilot/owner had never used automotive gasoline but could not attest to what previous owners had used. Further examination did not reveal any other preimpact anomalies with the engine that would have precluded normal operations. Although there was a potential for carburetor icing at glide power, based on the available evidence and that the airplane was taking off at the time of the accident, the engine likely lost power due to fuel starvation caused by debris obstructing the fuel outlet port of the fuel tank.
According to the pilot, the landing gear did not extend while on approach to a tower-controlled airport. The pilot attempted to manually extended the landing gear and made a low pass over the airport. The tower controllers described that the nose gear was down, and the main landing gear was not fully extended. The pilot declared an emergency and landed on the runway with the landing gear partially retracted. Postaccident examination of the landing gear hydraulic system revealed a leak traced to the right main landing gear actuator O-ring pressure line. The actuator pressure-side O-ring was replaced, the actuator was reinstalled, and the hydraulic system maintained hydraulic pressure with no additional anomalies. According to the airframe and powerplant mechanic, the actuator O-ring showed signs of deterioration. Evidence supports that the deteriorated actuator O-ring resulted in a failure of the landing gear hydraulic system, specifically, the right main landing gear.
The pilot stated that he was at an enroute altitude of 1,500 ft mean sea level (500 ft above ground level), tuning a radio to the destination frequency, when he looked up there was a “drone hovering” in the path of the helicopter. He reported that it struck the main rotor disk at the 2 o’clock position and it “disintegrated.” The pilot evaluated the helicopter for vibrations or damage and elected to return to the departure airport, which was 3.5 miles away. He subsequently landed the helicopter without issue and during the postflight examination, he noted substantial damage to one of the main rotor blades. A sample was taken at the site of the main rotor blade damage and tested negative for bird DNA. A search for the unmanned aerial system was performed, however, no device was located. No Low Altitude Authorization and Notification Capability (LAANC) authorizations were requested for the area at the time of the accident. Additionally, no operational waivers had been filed with the Federal Aviation Administration for unmanned aerial system operations in the area at the time of the accident.
The pilot in the tail-wheeled equipped airplane reported that, during the landing roll, he encountered a wind gust. The airplane subsequently veered to the left and ground loop off the runway. The airplane sustained substantial damage to the fuselage and left wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.
On June 22, 2022, about 1645 eastern daylight time, a Bell Helicopter UH-1B helicopter, N98F, was destroyed when it was involved in an accident in Amherstdale, West Virginia. About 15 minutes after the flight departed, the helicopter impacted two powerlines and a rock face during a forced landing, and a postcrash fire ensued. The pilot and five passengers were fatally injured. The helicopter was operated by MARPAT Aviation under the provisions of Title 14 Code of Federal Regulations Part 91
The pilot reported he was soaring when he penetrated two areas of “heavy sink” before reaching the final wave lift of the flight that took him to 16,500 ft.  When he left the wave lift the glider began to sink and he quickly focused on regaining lift and did not think about the final glide back to the departure airport. The pilot subsequently overflew a suitable alternative airport as he continued to search for lift while the glider continued to sink at about 1,000 ft per minute. The pilot eventually maneuvered into a position where his best option was to land in a lake when he could not find sufficient lift or return to an airport. Both wings were substantially damaged when the pilot landed in the lake. The pilot reported that there were no preaccident mechanical malfunctions or failures with the glider that would have precluded normal operation.
The pilot departed and remained in the airport traffic pattern. While on the downwind leg, he applied carburetor heat then reduced power to 2,000 rpm. Abeam the approach end of the runway, he reduced power further, then turned onto the base leg, where he recognized that the engine had lost power. After turning onto final approach and realizing that the airplane would not reach the runway, he performed an off-airport landing in a field, resulting in nose-over and substantial damage to the left wing, fuselage, and aft empennage.Postaccident examination of the engine revealed no evidence of preimpact failure or malfunction of the powertrain, ignition, air induction, exhaust, or carburetor heat systems. Although there was fuel contamination (particulates) found in the carburetor and airframe fuel strainer, and fibrous material inside the carburetor inlet screen, the amount and location of the contamination likely existed at the time of takeoff and the pilot did not report a loss of engine power until being at a reduced power setting on the base leg of the airport traffic pattern. Reported weather conditions were conducive to the formation of carburetor icing at glide and cruise power. Although the pilot reported that he applied carburetor heat before reducing engine power while on the downwind leg of the traffic pattern, it is likely that the ice accumulated to the degree that the carburetor heat was insufficient at the partial power setting to melt the ice that had accrued, resulting in a partial loss of engine power.
The pilot in the amphibious airplane reported that, he was going to land on the runway. During the approach he slowed too much, and the airplane bounced during the landing. The pilot elected to go around but retracted the landing gear before applying power. The airplane subsequently settled to the runway with the landing gear retracted. The keel of the amphibious airplane was substantially damaged. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.
The flight instructor reported that after demonstrating maneuvers he noticed that the glider had quickly descended to pattern altitude, so he proceeded into the traffic pattern. He slowed the glider to minimum sink airspeed and then turned onto the base leg about 200 to 250 ft above ground level. During the base leg turn, the glider continued to turn and descend, and the flight instructor was unable to maintain control. The glider impacted terrain short of the runway and sustained substantial damage to the fuselage, empennage, and both wings. The flight instructor reported that there were no preimpact mechanical malfunctions or failures with the glider that would have precluded normal operation. The flight instructor reported that there was sinking air in the flight area.
The pilot in the tailwheel equipped airplane reported that, shortly after touchdown, the airplane turned slightly to the left. The pilot applied right rudder control to correct the left turn, however the left turn increased before he could apply right side braking and power. The airplane departed the left side of the runway, ground looped and nosed over. The right-wing strut and vertical stabilizer were substantially damaged. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.
The student pilot was landing the airplane and during the landing flare the airplane bounced twice before the nose landing gear collapsed. This resulted in substantial damage to the fuselage aft of the firewall. The pilot stated that there were no preimpact mechanical malfunctions or failures that would have precluded normal operation.