roccoangelella/AeroGraph huggingface dataset:
The pilot observed a high voltage warning during the experimental amateur-built airplane’s takeoff roll on the 5th flight during phase 1 testing. The pilot continued the takeoff and the airplane climbed normally to an altitude of 50 ft. When the pilot raised the landing gear, the engine immediately lost all power. He performed a forced landing straight ahead to a field, during which the fuselage sustained substantial damage. A postaccident examination of the airplane by the pilot revealed that the primary alternator circuit breaker was open. The airplane was equipped with two electrical busses, an airframe bus and an isolated engine bus. The airframe bus included a 60-amp primary alternator, a 20-amp secondary alternator, and an electro-hydraulic power pack that provided hydraulic pressure to operate the landing gear. The power pack’s electric motor required an estimated 40-42 amps for startup. Given the high voltage warning and open primary alternator circuit breaker, it is likely that the primary alternator went offline at some time during the takeoff before the pilot attempted to raise the landing gear. As he moved the landing gear lever, the hydraulic pump startup demand likely exceeded the capacity of the airframe electrical bus while operating with only the 20-amp secondary alternator. The airframe electrical bus provided power to the engine electrical bus. The engine electrical bus powered the engine’s electronic fuel injection and ignition system, which required an estimated 24 amps to operate. The high demand on the airframe bus due to the landing gear operation while the bus was operating off of the secondary alternator likely reduced or interrupted its ability to provide power to the engine electrical bus. The engine bus was equipped with a backup battery intended to provide power to the fuel injection and ignition systems in the event of a loss of electrical power from the airframe bus. The battery remained Page 2 of 6 ERA22LA155intact and able to energize the engine bus after the accident; however, neither of the electric fuel pumps would rotate. Although the fuel pumps were not examined and may have been damaged during the accident, given the loss of electrical power followed by loss of engine power, it is more likely that the backup battery system was unable to sustain the required load of the fuel injection/ignition system. The cause of the initial overvoltage and the alternator circuit breaker opening was not determined. The pilot suggested that an alternator overspeed due to an improper pully diameter, or loss of an electrical ground connection, could have resulted in an overvoltage.
The pilots reported the engine began to vibrate and lose power while on the downwind leg in the traffic pattern. The pilot in the right seat took control and attempted to conduct a downwind forced landing to the runway, but the airplane’s flight path continued beyond the end of the runway into uneven terrain and the airplane nosed over. The airplane sustained substantial damage to both wings and the vertical stabilizer.Postaccident examination revealed the No. 1 cylinder rocker shaft bosses were fractured. Further examination of fracture surfaces with a stereomicroscope revealed fatigue crack initiation at and progression from the rocker shaft bore hole.In 1996, based on a history of fatigue cracking of cylinder rocker shaft bosses, the Federal Aviation Administration issued an airworthiness directive (AD) that required inspection of the cylinder shaft rocker bosses at the next overhaul or cylinder removal. Since the engine was last overhauled in 1978 and the No. 1 cylinder was last removed 1991, compliance with the AD was not required for the accident airplane’s No. 1 cylinder.
The pilot of the tailwheel equipped airplane reported that, during the takeoff roll, after the tailwheel came off the ground, the airplane veered left and exited the side of the runway. The pilot rotated the airplane to lift off the ground and remain in ground effect, but the main landing gear impacted a snowbank. The airplane nosed over and came to rest inverted, which resulted in substantial damage to the empennage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.
The pilot reported that he was on approach to a hospital rooftop helipad that he had never landed at before. About 30 ft above ground level, he felt a “thump” in the pedals; the helicopter vibrated, pitched forward, rolled left, then yawed right. The pilot landed the helicopter on the helipad. After the accident the pilot discovered that the tail rotor had contacted the building.  The helicopter sustained substantial damage to the tail rotor, tail rotor drivetrain, and tail pylon. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.
The pilot reported that he noticed the engine oil pressure dropped to 14 psi after he began the descent to his destination airport. He turned toward a nearby airport, but shortly thereafter the oil pressure dropped to 0 psi and the engine seized.  The pilot executed a forced landing to a field and the airplane sustained substantial damage to its wings when it struck fences and livestock feeding troughs during the landing.Postaccident examination of the airplane revealed several missing and loose bolts securing the engine valve covers. The No. 4 cylinder valve cover was completely off and its gasket was not located after the accident. The No. 6 cylinder valve cover was very loose and was only held on by 4 of the 8 bolts normally used to secure the cover. The No. 4 cylinder valve arm shaft bolt was missing. Metal shavings were observed throughout the valve assembly area as well as deposited on the cowling and airplane along with the lost engine oil.Review of maintenance records did not reveal any recorded maintenance to the rocker covers since the most recent engine overhaul 6 years before the accident. Maintenance entries since the overhaul indicated routine maintenance, including annual/100-hour inspections and oil changes, with no leaks detected during post-maintenance engine runs. Attempts to discover when the rocker covers were last accessed for maintenance were unsuccessful.Based on the available evidence the loss of engine power was due to oil exhaustion that resulted from improper installation of the engine valve covers. Determination of when the improper maintenance was performed could not be determined based on the maintenance entries that were available.Page 2 of 7 CEN22LA140
During a cross-country flight, about 50-miles from the destination airport, the engine began to run rough. The pilot continued toward the airport and tried to resolve the engine issue. The No. 6 cylinder dropped offline, followed by the Nos. 2 and 4 cylinders. The engine was still running, but the pilot could not maintain enough altitude to make it to the airport. The pilot executed a forced landing in a snow-covered field. The airplane nosed over during the landing, which resulted in substantial damage to the engine firewall. Downloaded engine monitoring data showed the No.6 cylinder stopped operating, followed by the Nos. 2 and 4 cylinders, consistent with the pilot’s statement. Oil was found on the belly of the airplane during initial examination. The data showed that the cruise power setting during the accident flight was 0.1 inches of mercury above the maximum cruise power setting listed in the flight manual. The recorded fuel flow was also above that expected for the maximum cruise power setting at the altitude flown.During detailed teardown examinations of the engine, all six piston heads were found with various degrees of pitting damage. The most significant damage was found on the No. 2, 4, and 6 pistons. The damage found was consistent with detonation. The connecting rods exhibited thermal damage and the oil sump and oil filter contained aluminum particles. The fuel distribution spider valve and the fuel injectors were found normal and not obstructed. The metal fragments from the piston heads most likely obstructed the oil journals in the crankshaft and prevented oil from reaching the connecting rods and bearings. Thermal damage found within the rods and bearings of the engine likely resulted from the oil starvation. Review of the engine logbooks did not reveal any uncorrected mechanical defects. The loss of engine power was likely due to detonation that damaged the piston heads and resulted in their subsequent failure. Page 2 of 6 CEN22LA144
The pilot reported that the airplane encountered a crosswind gust during the landing roll and subsequently departed the left side of the runway pavement. The left main and nose landing gear sunk into the soft ground adjacent to the runway which resulted in substantial damage to the engine mount. The pilot stated that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.
The pilot of the tailwheel-equipped airplane reported that, during the landing roll, as the tailwheel touched down, airplane veered to the right and ground looped. The left wing and aileron 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 pilot purchased the airplane about 6 months before the incident; however, he did not have a current Federal Aviation Administration (FAA) medical certificate and had not previously flown the airplane.  A family member reported that the pilot often went to the airport at night to run the airplane’s engine and taxi around the airport property. In the early morning hours on the night of the incident, the airport was unattended and the weather conditions were conducive to low visibility in mist. Later that day, the airplane was found inverted in the grass off the end of a taxiway and down an embankment. The pilot was fatally injured.Examination of the incident site revealed that the airplane likely traveled off the end of the taxiway and went about 130 ft down an embankment before it came to rest inverted, sustaining substantial damage to the airframe in the process. Tire (skid) marks consistent with the left and right main landing gear tires braking were observed leading up to the edge of the taxiway at the top of the embankment. The postincident examination of the airplane also revealed that it was not configured for takeoff. Even the pitot tube cover had remained installed on the pitot tube. During the examination, no evidence of any preimpact failures or malfunctions of the airplane or engine were discovered that would have precluded normal operation.The pilot had moderate to severe atherosclerosis of two coronary arteries. While this condition placed him at an increased risk for a sudden cardiac event, the autopsy findings indicated that the pilot initially likely had initially survived the impact. Thus, the pilot’s cardiovascular disease was not a contributing cause to the incident. Toxicology testing revealed that the pilot had used cannabis. THC and 11-OH-THC were detected in his blood at low concentrations. While the pilot was found to have cannabis in his system, it could not be determined if the Page 2 of 8 ERA22FA153concentration would have been impairing and influenced his ability to control the airplane on the taxiway.The late-night taxiing of his airplane was typical behavior for the pilot. All evidence indicated that there was no intent for flight as the airplane was not configured for, or in a position to conduct a takeoff. It is likely that, with the pitot cover still on the pitot tube, which would have prevented use of the airspeed indicator, the pilot did not realize how fast he was taxiing. He also may not have realized in the darkness and reduced visibility due to mist that he was quickly approaching the end of the taxiway. This was supported by the presence of the skid marks leading up to the edge of the taxiway and the top of the embankment. Based on this information, it is likely that the pilot lost control of the airplane while taxiing and overran the taxiway edge, after which the airplane traveled down the embankment and came to rest inverted.
The pilot back-taxied the airplane for departure and then began a 180° left turn to align the airplane with the runway centerline when the right main landing gear collapsed. The gear collapse resulted in substantial damage to the right elevator. A postaccident examination of the airplane revealed fractures to the bellcrank lower arm fork, bellcrank, pivot bolt, and trunnion bellcrank lug at the right main landing gear, which all displayed signatures consistent with overstress. The airplane had recently been repaired following another right main landing gear failure. During the repair the accident pilot, who was also the mechanic, adjusted the down lock tension as required by the maintenance manual and returned the airplane to service after he determined that the tension was within limits. A statement from the airplane manufacturer suggested that the failure may have been the result of an improper down lock tension adjustment. However, there was insufficient evidence in the investigation to show whether the pilot performed the adjustment incorrectly, thus the cause of the landing gear failure is undetermined.
According to the pilot, the purpose of the flight was to practice wheel landings in the tailwheel equipped airplane. The third approach was normal, and the airplane touched down to the right of centerline of the runway. The pilot applied left rudder to maneuver the airplane onto the centerline and “inadvertently engaged” the toe brake, which resulted in a veer to the left. The pilot attempted to correct the turn; however, he “over corrected” and the airplane departed the right side of the runway into the grass. The airplane nosed over and came to rest inverted, which resulted in substantial damage to the fuselage and right wing. The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.
The fuel-injected engine lost power on final approach.  Efforts to restore engine power were not successful and the flight instructor executed a forced landing about 1/2-mile short of the runway.  A postimpact fire consumed portions of the fuselage and right wing.  Postrecovery airframe and engine examinations revealed no anomalies that would have precluded normal operations.  However, examination of the airframe fuel system was hindered by the extent of the fire damage.  Available information indicated that sufficient fuel was onboard for the airplane.  As a result, the investigation was unable to determine the reason for the loss of engine power.
The pilot of the tailwheel equipped airplane reported that, during the landing the airplane bounced, he added power and landed a second time about halfway down the runway. Subsequently, he lost directional control which resulted in a ground loop and runway excursion. The left wing, left horizontal stabilizer and left elevator were substantially damaged. The pilot reported no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.
The pilot in the tailwheel equipped airplane reported that while landing with a crosswind from the right, the airplane veered left. The pilot applied aft pressure to the control stick and brakes, but the airplane nosed over substantially damaging the rudder. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.
The flight crew reported they flew a normal flight and a stabilized approach in gusty wind conditions. Performance data indicated they would require about 3,000 ft of runway for landing on the 6,995 ft long runway, and they added 5 knots (kts) to the approach speed due to the gusts. Data indicated that the airplane landed in the touchdown zone and at an appropriate airspeed of 110 kts (104 kts groundspeed); however, the pilot’s and co-pilot’s application of brakes was unsuccessful in achieving sufficient braking action. The airplane departed the runway at a groundspeed of 58 kts and came to rest against a perimeter fence 450 ft past the runway. A witness stated the airplane landed long; however, his distance from the runway and his angle of view of the airplane may have prevented an accurate assessment. Although the airplane flight manual states that if the brake system or antiskid fails, the pilot(s) are to attempt to pull the emergency brake, the pilots were unable to locate the emergency brake and instead pulled the parking brake.Although an examination of the braking system failed to find an anomaly, a performance study revealed that during the ground rollout the deceleration was primarily due to aerodynamic drag and free rolling “unbraked” wheel friction for about 5,000 ft and that there was virtually no evidence of deceleration due to hydraulic or pneumatic wheel braking during the rollout. However, the pilots’ inability to locate and use the emergency brake contributed to the insufficient braking. The crew failed to immediately recognize the issue and locate and utilize the emergency brake for supplemental braking authority.
The airplane was on an instrument approach when the pilot attempted to extend the landing gear. During the gear extension process, the passengers heard a “loud bang” under the floor panels, and the pilot reported that the gear would not extend. The pilot diverted to another airport and attempted to extend the landing gear manually, which was unsuccessful as the landing gear system was jammed. The pilot landed with the gear retracted and the airplane sustained substantial damage to the fuselage and empennage. A postaccident examination of the landing gear revealed that the gear was still jammed and could not be actuated with the gear handle or by manual extension. The right landing gear drive shaft was unable to rotate and exhibited a binding during the rotation attempt. The examination and disassembly of the right main landing gear actuator revealed that the initial failure originated between the bevel gear set. The pinion gear and driven gear exhibited damage and fractures of their respective teeth. The cracked teeth and pitch line pitting present on the pinion gear indicate that it exhibited fatigue wear prior to the failure of the bevel gears. The final surface of the driven gear was significantly smeared, which obstructed the examination and analysis of the surfaces for fatigue-like cracks and wear patterns. Although the failure was within the bevel gear set, the initiating gear failure could not be determined due to the damage. The pinion gear had effective case depth but did not meet the drawing requirements for minimum case hardness. The driven gear did not show evidence of case hardening and did not meet the drawing requirements for both effective case depth and minimum case hardness. Since the bevel gear set were operational for more than 12,000 cycles, it is likely that the case hardness did not contribute to the gear failure.Page 2 of 7 CEN22LA138
The pilot of the airplane reported that, while on short final to land, the airplane experienced a sudden loss of airspeed due to windshear. The pilot continued the approach and reported that he flared too high, and the airplane bounced during landing. He elected to go around, and during the second landing the airplane bounced again. During the third landing attempt, the pilot successfully landed the airplane.  The airplane sustained substantial damage to the forward fuselage undercarriage. The pilot reported there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.The automated weather observation station located on the airport reported that, about the time of the accident, the wind was from 330° at 12 knots. The pilot reported that during the accident flight, the wind was at 12 knots, gusting to 20 knots. The airplane landed on runway 30.
The pilot reported that during the cross-country flight, the engine began to lose power and as he attempted to regain power, he noted a decrease in fuel pressure. The engine then lost all power, and the pilot made a forced landing on a road. Postaccident examination of the airplane found that the aluminum fuel line from the fuel indicator to the carburetor had ruptured. Additionally, minor corrosion was present around the ruptured area. Based on this information, it is the likely that this corrosion ultimately resulted in the rupture of the fuel line and loss of engine power. Additionally, the airframe maintenance manual prescribed that all fuel lines should have been inspected during the airplane’s most recent annual inspection, which had occurred 8 months and 22 flight hours prior to the accident. Had the corrosion been detected, and the fuel line replaced at that time, it is likely that the loss of engine power would not have occurred.
The pilot reported that he encountered a very strong gust of wind during landing rollout, which pushed the airplane off the runway into a ditch. Subsequently, the airplane nosed over and sustained substantial damage to the right wing and vertical stabilizer. The pilot reported that the airplane had no preimpact mechanical malfunctions or failures that would have precluded normal operation.
The operator reported that the pilot had diverted to an alternate airport due to weather. As the flight approached the alternate airport, the weather had deteriorated, and the pilot requested a Special VFR clearance. The flight continued to follow the lake shoreline and the pilot recalled circling once while waiting for the clearance. Prior to reaching “the mouth of the river”, the pilot made the decision to divert to another alternate airport, due to the visibility getting worse as they approached the airport. As the pilot began to make an approximate 20° right hand turn over the frozen, snow-covered lake, he noticed the airplane was losing altitude and remembers increasing power and pitch, around this point he “switched to instruments”. The passenger recalled looking to his right and remarked it was like looking at a “white sheet of paper” with the sky blending with the frozen lake. Moments later, the airplane impacted the snow-covered ice while in the turn to the right. The airplane sustained substantial damage to the wings, fuselage, and empennage. The operator reported that there were no mechanical failures or malfunctions with the airplane that would have precluded normal operation.
The pilot of the personal flight planned to remain in the departure airport’s traffic pattern. During the departure climb, the airplane experienced a loss of engine power. The pilot preformed a forced landing on a field, and the airplane sustained substantial damage on impact with terrain to the engine mount. The pilot stated that he had the fuel selector positioned to the left main fuel tank for the flight. Postaccident examination revealed 16 gallons of fuel in the left main fuel tank. Minimal fuel was found in the engine carburetor bowl, and no fuel in the fuel line leading to the carburetor, which was consistent with fuel starvation to the engine. There were no mechanical anomalies identified that would have precluded normal engine operation.
The pilot reported that the tailwheel-equipped airplane drifted right during the landing rollout in crosswind conditions. The pilot applied left rudder to correct the deviation; however, the right main landing gear contacted a snowdrift on the runway edge and the right wing impacted a snowbank. The airplane then yawed right, departed the runway, nosed over, and came to rest inverted, which resulted in substantial damage to the fuselage and rudder. The pilot reported that the airplane had no preimpact mechanical malfunctions or failures that would have precluded normal operation.