roccoangelella/AeroGraph huggingface dataset:
The pilot of the helicopter stated that, while maneuvering around the area looking for a suitable landing site, a dirt turnout alongside a road was selected. A tree was noted on the edge of the turnout. An approach was initiated to the site and expected brownout was encountered. About 5 ft above ground, the pilot heard the crewmember in the back of the helicopter call out “hold.” The pilot arrested the descent and came to a hover. Within seconds the asphalt roadway reference was obscured by the brownout and he lost visual reference. He announced, “lost visual” and started to climb, which was his last recollection before regaining consciousness.The crewmember in the back of the helicopter reported that the helicopter approached the landing zone angled, to the south toward a tree. About 7 to 10 ft above the ground, he noticed that the helicopter was drifting forward, and he called out twice, “You are drifting forward, hold.” The helicopter continued to drift and subsequently, struck a tree and rolled onto its left side. The helicopter sustained substantial damage to the fuselage and main rotor system.The pilot reported there were no mechanical malfunctions or failures with the helicopter that would have precluded normal operation.
The pilot reported that, he entered a valley and descended to an altitude of about 300 to 500 ft above the ground. As the pilot began a climb to clear an upcoming ridgeline, he realized that the airplane would not clear the terrain despite making S-turns and adjusting to best rate of climb airspeed. Subsequently, he initiated an emergency landing and the airplane impacted terrain in a level attitude, which substantially damaged the left wing and underside of the airplane. 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 he had observed the student pilot use a dipstick to determine the fuel quantity. They then departed for a training flight with the belief that they had 10 gallons of fuel. They performed flight maneuvers for about 20 minutes then returned to the airport for pattern work. On the third takeoff, about 300 ft above ground level (agl), the engine experienced a total loss of power. The flight instructor initiated a forced landing to a road where the airplane struck a curb, which resulted in substantial damage to the right wing. After a debrief with the student, it was discovered by the flight instructor that the student may have inserted the fuel dipstick into the tank at an angle instead of vertically and got a higher level indication of fuel quantity.    A postaccident examination of the wing tanks by the recovery agency, revealed less than a half-gallon of fuel remaining in the tanks.The pilot reported there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.
The pilot of the airplane reported that, during the landing roll, the airplane was not slowing as expected. The pilot firmly applied braking action with no corresponding slowing action from the airplane. When he and his passenger saw the departure end of the runway approaching, they both applied as much brake pressure as possible without any effect. The airplane departed the runway and came to rest in a ditch, resulting in substantial damage to the engine mount. The airplane’s brake system was inspected by a mechanic who reported that the left side brake functioned, however it had a minor amount of air in the system and may not have had the same working pressure as the right-side brake.  The pilot reported that there were no other preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.
The pilot reported that while in the landing flare, about 5 to 7 ft above ground level, the airplane “suddenly dropped” to the ground and the airplane’s tail struck the runway. The pilot then taxied the airplane to parking uneventfully. During a subsequent inspection of the airplane, the pilot and a mechanic found that the airplane’s empennage had sustained substantial damage. The pilot reported that there were no preaccident mechanical malfunctions or failures of the airplane that would have precluded normal operation.
The pilot held a commercial pilot certificate with airplane ratings but did not possess a helicopter rating at the time of the accident. He did have a logbook endorsement for solo student flight with helicopters with the prohibition of carrying passengers. The passenger was a pilot-rated for single-engine land airplanes and did not have any helicopter experience. According to automatic dependent surveillance-broadcast data, the helicopter departed an airport and flew north over swampy, state land. The data further showed the helicopter flying at altitudes from 25 to 75 ft above ground level (agl) and at speeds between 83 to 100 knots before colliding with high-voltage power lines. The helicopter came to rest in a swampy field about 250 ft from the power lines. The power lines were measured at 80 ft agl. Examination of the wreckage did not reveal any preimpact mechanical malfunctions. The circumstances of the accident are consistent with the pilot’s failure to maintain clearance from power lines while maneuvering at low altitude.
The pilot reported that while taxiing to the ramp for parking behind another airplane, the airplane in front of him suddenly stopped and he impacted that airplane from the rear. He said that all he heard was the propeller of his airplane hitting the tail of the airplane in front of him. He immediately shut down the engine of his airplane and the airplane that had been struck taxied to the ramp and parked. The airplane that was impacted sustained substantial damage to the tail and the other airplane sustained minor damage. There were no reported preaccident mechanical malfunctions or failures to either airplane that would have precluded normal operation.
The non-instrument-rated pilot and 2 passengers departed on a visual flight rules cross-country flight. Air Traffic Control (ATC) radar and Automatic Dependent Surveillance-Broadcast (ADS-B) data indicated that after takeoff the airplane tracked north and climbed to a cruise altitude of 8,500 ft and then later climbed to 16,500 ft. About an hour and 25 minutes later, the airplane began a descent and turned momentarily to the east. The airplane then turned west and back to the north while it descended. The ground speed decreased from over 200 kts to under 100 kts. Mode C position reporting data was lost followed by the loss of all track data. The airplane was not in contact, nor was it required to be in contact, with ATC.A witness in the area reported that he heard what sounded like a motocross bike engine revving to full throttle. He then looked up and saw what he initially thought was a weather balloon coming straight down. He realized it was an airplane and videoed the airplane in its descent. The airplane was in a right-hand nose-down spin. The video showed the airplane descend until, moments before impacting terrain, it became obscured by tall grass. In the video, the airplane’s aft fuselage and empennage were separated and neither the propellers nor the outboard wings and fuel tip tanks were seen.Instrument meteorological conditions (IMC) existed in the area, where Mode C position reporting and all track data was unavailable.A postaccident examination of the airplane revealed no mechanical failures or malfunctions that would have precluded normal operation. The airplane had a serviced oxygen system; however, no oxygen masks or cannulas were found in the wreckage, and the pilot’s mechanic and flight instructor stated that they were not kept on board the airplane. Federal Aviation Regulations require all occupants on board to use supplemental oxygen above 15,000 ft mean sea level. The pilot’s operation of the airplane above this altitude for almost 90 minutes would Page 2 of 12 CEN22FA145have likely led to a performance impairment resulting from hypoxia. The airplane’s track deviations away from its intended destination could have been the result of one or more of the following: 1) an attempt to maneuver the airplane to avoid IMC; 2) the pilot’s impaired performance as a result of hypoxia; and/or 3) the onset of spatial disorientation. However, there was insufficient evidence from which to determine the degree to which hypoxia and spatial disorientation played a role in the sequence of events leading to the airplane’s departure from controlled flight.
The pilot stated he was previously aware of the nose-over issue of the various models of the aircraft, and as such was very cautious during landing. He attempted to recover after bouncing on a grass runway but on the second touchdown with aft elevator control input, the nose landing gear dug in and the airplane nosed over, which resulted in substantial damage to the rudder. He indicated that he should have done an immediate go-around as a result of the bounced landing, and not attempted to recover.According to the photographs and information provided by airplane owner/pilot, the nose gear leg was bent aft about 60° beginning about 2.25 inches from the landing gear mount. Equipment that was attached to the nose gear leg was permanently deformed.The airplane was equipped with upgraded nose gear leg and nose wheel fork that were specified by Van’s Aircraft Service Bulletin (SB) 07-11-09. Those components were designed to reduce the likelihood of fork axle-to-runway surface contact during nose gear overload conditions.
The pilot reported that his approach to landing was normal.  He said that during the landing roll he felt nose gear “dig in” just before the nose gear collapsed, and the airplane nosed over inverted onto the runway, which resulted in substantial damage to the airframe. After exiting the airplane, the pilot observed that the grass/turf landing surface was loose and uneven. Inspection of the grass runway surface revealed the dirt was soft, and a ground scar was created by the nose wheel. A post-accident examination of the airplane revealed a fractured wheel pant and scarring on the lower right-wing skin. The pilot reported no mechanical anomalies prior to landing.
During longline operations, and while flying to a structure, the helicopter sustained a partial loss of engine power. The helicopter was at 90ft above ground level and about 30 kts airspeed, when the pilot lowered the collective to attempt an autorotation. There was insufficient altitude and airspeed to increase main rotor rotation, and the helicopter impacted a muddy grass hill. The helicopter came to rest on its right side. After the helicopter came to rest, the pilot noticed the engine was still, “at a slow run, less than idle.” The helicopter sustained substantial damage to the fuselage, the main rotor system, and the tail rotor system. During the recovery of the helicopter from the field, it was noticed by the operator that the compressor discharge pressure (Pc) line B-nut connection at the fuel control unit (FCU) was not attached. It appeared the B-nut had backed off the FCU fitting.A postaccident examination was performed on the airframe with no anomalies noted. The engine was removed from the airframe and an engine test run was performed with no anomalies noted after the Pc line B-nut was properly torqued. During the Pc line B-nut torquing process, a “squeeze out” of pink paint, consistent with torque stripe paint, was observed emanating from the remaining threads on the line.On the day before the accident, the fuel control unit (FCU) was installed on the helicopter’s turboshaft engine. A calibrated torque wrench was used by the mechanic to tighten the various FCU B-nuts. The mechanic tightened and torqued each B-nut, one at a time, when completing the task. Another mechanic inspected the work after it was completed and found no issues. After the B-nuts were torqued, pink torque stripe paint was applied. Following the FCU installation, the fuel system was purged of air, and a leak check was performed with the helicopter running, an acceptable practice per the engine manufacturer, with no issues noted.Page 2 of 8 CEN22LA146It is likely that the mechanic failed to properly torque the B-nut that secures the Pc line to the FCU, which resulted in a partial loss of engine power due to the Pc line separation. Based on the available evidence, it was undetermined as to why the mechanic failed to properly torque the B-nut.
The pilot and two friends flew their individual airplanes from their home airport on the mainland to an airport on an island in the Florida Keys to meet for lunch. Upon arrival, the pilot landed opposite the direction of other landing traffic and subsequently taxied erratically for 6 minutes, unresponsive to radio calls. The pilot had to be directed by a lineman to park at the location where his friends waited. The lineman stated that the pilot had difficulty getting out of the airplane, appeared “befuddled,” and did not respond to questions. When confronted by another pilot about the opposite-direction landing, the pilot did not respond, and his friends defended him. The lineman reported that the pilot was “devastated” by what he had done, but the only unusual behavior cited by his friends was that the pilot did not eat his lunch. The accident occurred on the return flight, which was conducted during the day and in visual meteorological conditions, and during which the airplane was lost from radar over the Gulf of Mexico. Debris from the airplane was recovered from the surface of the ocean, and the airplane was presumed to be destroyed. Flight track data revealed multiple altitude, heading, and speed excursions on both the accident flight and the previous flight; however, the airplane’s flight track was not erratic at the time radar contact was lost.Pre-event medical records showed that the pilot had multiple medical conditions that significantly increased his risk for a sudden cardiovascular event, including coronary artery disease with stenting of several coronary arteries, previous myocardial infarct, hypertension, high lipid levels, diabetes, and obesity. The pilot’s remains were not recovered, and no autopsy was performed. Based on operational evidence, including interviews, flight track data, and medical risk factors, the pilot may have  been medically impaired or incapacitated at the time Page 2 of 9 ERA22LA162of the accident; however, given the available medical evidence, the reason for the impairment could not be determined.
The pilot reported that, he planned a full stop landing at his ranch in the tailwheel equipped airplane. The landing spot was a ploughed, wet, and muddy field. He flew three low approaches to confirm the area was free of hazards. After touch down, he realized he had landed a little fast and long, but because the main landing gear and tailwheel were on the ground, he decided a go-around was not feasible. The airplane then struck a fence and came to rest on its nose substantially damaging the left wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.
The pilot was also the owner and builder of the experimental amateur-built airplane. While returning to the airport after a local flight, the engine lost oil pressure, so the pilot diverted toward the nearest airport. The engine then began to run roughly and lost partial power. The airplane was not able to glide to the runway and collided with a ditch in a field during the forced landing. The pilot described that his postaccident examination of the engine revealed that the pinion gear on the pull starter motor fractured into several pieces that entered the accessory gear case, likely seizing the oil pump. About 4 years and 100 flight hours before the accident, the pilot had modified the pull starter motor from its original design so that the motor would fit in the airplane. Postaccident metallurgical examination found that the pull starter motor’s pivot lever was shortened. The pivot lever arm was designed to move the starter clutch and engage the pinion (small) gear to the crankshaft gear. The pinion gear teeth displayed indentations in their surfaces that indicated that they were only partially engaged to the crankshaft gear when the starter was being operated, a condition which was likely the result of the shortened pivot lever. This ultimately resulted in increased stress on the gear teeth during engine start and the subsequent failure of the gear in overstress. The liberated gear teeth likely damaged and seized the engine oil pump, and resulted in the partial loss of engine power.
Before departing on an instructional flight with a new student, the flight instructor added 10 gallons of automotive premium 93 octane fuel that contained ethanol to the airplane, which had a supplemental type certificate (STC) to be able to use automotive fuel. The instructor conducted the takeoff and initial climb to 2,500 ft mean sea level (msl). Once established, the instructor let the student handle the flight controls and instructed the student to maintain their heading but to continue to climb to 3,000 ft msl. After practicing some basic flight maneuvers, the instructor had the student fly straight and level about 2,500 ft msl over a lake. While they were roughly over the center of the lake, the engine sustained a “severe loss of power.” The instructor immediately took the controls and established best glide airspeed. He observed the oil temperature and pressure gauges to be normal. The fuel quantity gauge was still indicating full. He worked the throttle in and out but without effect. He then pulled the carburetor heat to on, but the propeller continued to windmill under no power. The lake was surrounded by high, dense trees, so he elected to conduct a forced landing to the water. During landing the airplane nosed over, resulting in substantial damage to the airplane. The instructor and student were uninjured and were able to exit the airplane and walk to shore.   The postaccident examination of the airplane and engine did not reveal any evidence of preimpact failures or malfunctions that would have precluded normal operation. A review of a carburetor icing probability chart indicated that meteorological conditions at the time of the accident were conducive to carburetor icing at glide and cruise power. Guidance published by the automotive fuel-use STC holder advised that automotive fuel containing ethanol should not be used in the airplane as, among other things, ethanol can absorb significant amounts of water in flight, and has an affinity for water and can pull moisture from inlet air on humid days to such extent that the engine may malfunction. Page 2 of 10 ERA22LA157Furthermore, carburetor icing is likely to occur at higher ambient temperatures, and at lower humidity with automotive fuel than with aviation fuel. The flight instructor did not know that he should not have been using automobile gasoline that contained ethanol.Thus, the evidence in this case indicates that in addition to not using fuel containing ethanol, the flight instructor should have responded to the carburetor icing by applying full carburetor heat immediately, instead of applying it after the engine had stopped producing power, as the carburetor heat system needed hot air from the exhaust manifold while the engine was running to function properly. He also could have recognized the potential for the formation of carburetor ice and preemptively activated it to prevent the formation of carburetor ice. Therefore, it is likely the engine sustained a complete loss of engine power due to the formation of carburetor ice.
The pilot reported that the helicopter was being used to transport skiers in support of a commercial Heli-ski operation when the helicopter inadvertently collided with terrain while maneuvering to land on the glacier.The pilot stated that while on approach to an area to pick up a group of skiers, flat light conditions made it difficult to discern topographical features on the snow-covered, featureless, glacial terrain. The pilot said that during the approach, he inadvertently allowed the helicopter to descend below his intended approach path, and the helicopter touched down short of his intended landing site.  The helicopter subsequently rolled to the left and the main rotor blades struck the snow-covered terrain. The helicopter sustained substantial damage to the main rotor blades, tail rotor blades, tail boom, and fuselage.The pilot reported that there were no pre-accident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.
The solo student pilot reported that, during touchdown, the airplane bounced twice before he added power, and landed without further incident. A postaccident examination revealed the underside of the fuselage sustained substantial damage. The student pilot reported that there were no preimpact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation.
The pilot in the retractable landing gear-equipped airplane reported that about 700 ft agl, he initiated a descending right turn for landing. The pilot attempted to lower the landing gear however, the landing gear would not extend even after troubleshooting the problem. The pilot recalled that the mixture was rich, the propeller was set to maximum rpm, and full throttle was applied when he aborted the landing, but there was no corresponding response from the engine. The propeller began to windmill, and he attempted to troubleshoot the total loss of engine power by moving the fuel selector from the right tank position to the left tank position and engaged the starter to no avail. During the forced landing, the empennage struck a barbed wire fence short of the runway, and the airplane came to a stop upright.The airplane sustained substantial damage to the empennage and horizontal stabilizer. The pilot reported there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.The post-accident examination revealed that the right-wing fuel tank was empty, and the left-wing fuel tank contained seven gallons of fuel.