roccoangelella/AeroGraph huggingface dataset:
The pilot reported that, during the preflight, it was snowing, and he wiped the snow that had accumulated on the wings off "as best as [he] could." He added that, while taxiing to the runway, "snow was falling heavily," and he observed "light accumulation of wet snow" on the wings. During the takeoff roll, he observed the snow "sloughing off" the wings as the airspeed increased. Subsequently, during the climb to about 150 ft above the ground, the airplane yawed to the left, and he attempted to recover using right aileron. He reported that he "could see a stall forming," so he lowered the nose and reduced power to idle. The airplane impacted the general aviation ramp in a left-wing-down attitude and slid 500 to 600 ft. The pilot reported on the National Transportation Safety Board Aircraft Accident/ Incident Report 6120.1 form that the airplane stalled, and he recommended "better deicing" before takeoff.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 airframe or engine that would have precluded normal operation.A review of recorded data from the automated weather observation station located on the airport revealed that, about 27 minutes before the accident, the wind was 010° at 8 knots, 1/2-mile visibility, moderate snow, freezing fog, and sky condition broken at 500 ft above ground level (agl) and overcast at 1,500 ft agl. The airplane departed from runway 16.The Federal Aviation Administration (FAA) Aeronautical Information Manual stated, in part: "The presence of aircraft airframe icing during takeoff, typically caused by improper or no deicing of the aircraft being accomplished prior to flight has contributed to many recent accidents in turbine aircraft."The manual further stated, "Ensure that your aircraft's lift-generating surfaces are COMPLETELY free of contamination before flight through a tactile (hands on) check of the critical surfaces when feasible. Page 2 of 6 GAA17CA158Even when otherwise permitted, operators should avoid smooth or polished frost on lift-generating surfaces as an acceptable preflight condition."FAA Advisory Circular, AC 135-17, stated in part: "Test data indicate that ice, snow, or frost formations having thickness and surface roughness similar to medium or course sandpaper on the leading edge and upper surfaces of a wing can reduce wing lift by as much as 30 percent and increase drag by 40 percent."Included in the public docket for this report is a copy of a service bulletin from the airplane manufacturer, which describes deicing and anti-icing ground procedures. It stated, in part:         During conditions conducive to aeroplane icing during ground operations, take-off shall not be attempted when ice, snow, slush or frost is present or adhering to the wings, propellers, control surfaces, engine inlets or other critical surfaces.         This is known as the "Clean Aircraft Concept". Any deposit of ice, snow or frost on the external surfaces may drastically affect its performance due to reduced aerodynamic lift and increased drag resulting from the disturbed airflow.
The commercial pilot was repositioning the helicopter from an offshore oil platform to the operator's home base in visual meteorological conditions. When the helicopter did not return as expected, the operator initiated a search; the helicopter wreckage was found in a shallow marsh area just off shore. No radio distress calls were received from the pilot, and the skid-mounted emergency float system was not deployed. Onboard flight-following equipment recorded a straight flight path tracking directly to the intended destination with a gradual descent just prior to impact.Accident flight data extracted from the helicopter's engine control unit did not show any faults with the engine. Detailed examinations of the helicopter's airframe, drive system, and flight controls did not reveal any preimpact anomalies. Examination and full teardown of the engine did not reveal any anomalies and indicated that the engine was operating at the time of impact. Airframe deformations were consistent with a slightly nose-low and left-skid-down attitude at the time of impact; therefore, it is unlikely that the pilot experienced a loss of control. Given the absence of mechanical anomalies, the fact that the pilot did not make a distress call or activate the emergency float system, and the helicopter's relatively straight recorded flight path, it is likely that the helicopter was operating normally at the time of impact. Further, toxicology testing and autopsy findings did not indicate any evidence of pilot impairment. It could not be determined why the pilot failed to recognize the helicopter's descent and maintain a proper altitude above the water.
The flight instructor and the commercial pilot receiving instruction were conducting a local training flight to practice aerodynamic spins. A review of air traffic control radar track data established that the airplane entered two aerodynamic spins during the flight. The first aerodynamic spin began at 10,300 ft mean sea level (msl), and the airplane descended about 1,000 ft before it recovered into a climb. The airplane then made a series of climbing turns until reaching 10,800 ft msl where it entered a second aerodynamic spin. The airplane did not recover from the second spin before it descended below available radar coverage at 6,800 ft msl (about 1,700 ft above the ground). Multiple witnesses reported seeing the airplane descending in a nose-down spin. One witness stated that the airplane completed about 5 turns in the spin before it descended behind a tree line into a reservoir.The airplane's Pilot Operating Handbook specified that at least 1,000 ft of altitude loss should be expected for a one-turn spin and recovery and that a six-turn spin and recovery may require more than twice that altitude loss because the airplane can develop a rapid rate of rotation and a steep nose-down pitch attitude. A postaccident examination revealed no evidence of a mechanical malfunction or failure that would have precluded normal operation during the flight. Additionally, the examination did not identify any foreign object debris that would have limited full movement of the flight controls during the flight, and the airplane's weight and balance were within the specified limits to conduct aerodynamic spins. It is likely that the pilots did not apply prompt and/or correct flight control inputs to adequately recover from the intentional aerodynamic spin.
The pilot of the helicopter reported that, during the hover-taxi for departure in the ramp area, he was monitoring another helicopter that had just departed and then "brought [his] eyes inside [the helicopter]" to switch a radio frequency. As the pilot looked back outside, he observed "the nose of a big plane taxiing" from behind another parked airplane to his left. Subsequently, the pilot abruptly applied aft cyclic to stop the helicopter's forward momentum, and the Fenestron struck the ramp. The pilot returned to the ramp area without further incident.The Fenestron sustained substantial damage.The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.
The student pilot in the tricycle-gear-equipped airplane reported that he was flying a solo cross-country flight and landed on the 60-ft-wide asphalt runway. He recalled that there were 4-ft-high snow berm that paralleled the edges of the runway. When he touched down, he applied the brakes, and the airplane yawed to the left. In fear of striking the snow berm, he initiated a go around and rotated about 65 kts. The airplane climbed about 2 ft above the runway, but the left main landing gear wheel struck the snow berm on the left side of the runway. The left tire and brake assembly separated from the airplane, and the airplane came to rest in the snow-covered safety area left of the runway. The airplane sustained substantial damage to the left wing ribs and aileron.The student reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.
The pilot reported that, during approach, he pushed the yoke forward to avoid a flock of birds in his flightpath, which resulted in an "increased and abnormal rate of descent." He was then unable to arrest the descent, and the "main landing gear made very hard contact with the runway." The airplane bounced, the nose landing gear collapsed, and the airplane came to rest nose down.The airplane sustained substantial damage to the firewall.The Federal Aviation Administration Airport Facility Diagram page for the destination airport in part states: "Birds on and invof [in vicinity of] arpt."
The private pilot was on the second leg of a cross-country flight in the helicopter. After about 45 minutes and while in cruise flight at 1,800 ft mean sea level, the engine lost total power; the low rpm warning sounded, and the pilot initiated an autorotation in the congested area during nighttime conditions. During the autorotation, the helicopter struck a building, which resulted in substantial damage to the fuselage. Postaccident examination of the engine revealed that the crankshaft gear bolt was about 3/16 inch from the seated position. The safety lockplate washer was worn, the back of the bolt head displayed rotational scoring, the bottom threads of the bolt were damaged, and the alignment dowel had sheared. The engine had accumulated 5.9 hours total time since undergoing major overhaul about 1 year before the accident. It is likely that, when the engine was overhauled, the crankshaft gear bolt was not properly seated against the gear, which resulted in the crankshaft gear disengaging from the accessory gears and a subsequent total loss of engine power.
The student pilot and flight instructor of the balloon were performing their ninth training flight. The instructor reported that, during the flight, the student made an approach to a grass field about 5 knots. During the landing, there were multiple touchdowns, and during the first, the balloon "rebounded back up" and touched down again about 65 ft northwest of the initial touchdown point. During the second touchdown, the student pilot put his right foot on the front of the basket to brace for the landing, and his left foot remained on the floor of the basket. The balloon touched down, and the student pilot rolled his ankle. The balloon "rebounded back up," and the flight instructor pulled the valve line to deflate the balloon. The balloon came to rest about 30 ft farther to the northwest. The student pilot sustained a broken ankle. The balloon did not sustain substantial damage.The student pilot reported that there were no preaccident mechanical malfunctions or failures with the balloon that would have precluded normal operation. Per the recommendation of the National Transportation Safety Board investigator-in-charge, the flight instructor reported the following:In an effort to prevent an accident similar to the one that occurred with N7423D, I will brief student pilots as to the importance of bracing oneself correctly and that two feet on the floor during touch downs will provide better stability from the human factors perspective of balance. I will also discuss this event in future safety forums within the balloon community in order to enhance safety. It is my belief that these actions will help to prevent any future occurrences of this nature.
The pilot of the tailwheel-equipped airplane reported that, while attempting to land on the "grass portion of the runway" parallel to the paved runway, the ground was soft. Subsequently, the main wheels sunk into the ground, and the airplane nosed over.The airplane sustained substantial damage to its right-wing lift strut and vertical stabilizer.The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.
The instrument-rated private pilot had filed an instrument flight rules (IFR) flight plan for the cross-country flight, but intended to depart under visual flight rules conditions and open his IFR flight plan shortly after takeoff. He stated that, during the preflight inspection, he did not see any low clouds and was able to see stars above him. The airplane departed shortly before sunrise, and the pilot stated that, while retracting the flaps after takeoff, he encountered low-level fog about 300 ft agl and the airplane entered instrument meteorological conditions. The pilot made a right turn to avoid the final approach course to the opposite runway, then saw a tree and attempted to avoid impacting it; he then recalled waking up in the airplane on the ground. Weather conditions near the accident site about the time of the accident included scattered clouds at 500 ft and a visibility of 6 miles in mist. The series of events described by the pilot was consistent with a loss of control due to spatial disorientation, likely due to the unexpected loss of visibility during the initial climb.
The airplane was parked on the operator's ramp when Federal Aviation Administration inspector(s), during a routine ramp inspection, found that the airplane had substantial damage to the firewall and structure aft of the firewall. Airplane maintenance records showed an entry stating that the damage was due to a suspected hard landing. The operator stated that the damage must have occurred between the airplane's 100-hour inspection on September 27 and an oil change performed on October 24, 2016. The operator's mechanic stated that the damage was found when the engine cowl was removed for the oil change. A review of airplane flight logs showed about 20 different people had flown the airplane over 48 flights between the time of the 100-hour inspection and the oil change. On October 8, 2016, a student pilot was performing touch and gos when the airplane bounced two or three times during the flight's final landing. The student pilot stated that, when she turned off the runway onto the taxiway, she noticed the airplane was not steering properly and reported to the air traffic control tower that she had some mechanical difficulty that required maintenance assistance. The student pilot's flight instructor and a company lineman responded and noticed that the airplane had a flat nosewheel tire. The lineman inflated the tire, and the student pilot and flight instructor taxied the airplane to the operator's maintenance facility. The flight instructor informed the operator's mechanic of the bounced landing and flat tire. The mechanic stated that he replaced the nose tire, performed a brief exterior walk-around visual inspection of the airplane, noting it appeared airworthy, and returned it to service. A hard landing inspection was not performed. Other than the bounced landing reported on October 8, 2016, no other concerns about the other flights were reported to the operator.
The pilot of the tailwheel-equipped airplane reported that, after conducting two touch-and-go landings at a nearby airport, he decided to land at a different airport to speak with a friend. He added that everything seemed normal during the touchdown on the snow-covered runway but that the airplane then "abruptly stopped and [nosed] over." The airplane sustained substantial damage to both wings and the rudder.The pilot reported that the inside of the left main landing gear and brake was "packed with ice" and had frozen, which prevented the wheel from rotating during the landing roll.
The pilot of a tailwheel-equipped airplane reported that the airplane veered to the right and then left. He corrected the veer to the right but "didn't get on it quick enough to stop the turn." The airplane continued to the left and ground looped. A postaccident examination revealed that the airplane sustained substantial damage to the right wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The automated weather observation station on the airport reported that, about the time of the accident, the wind was from 190° at 6 knots. The pilot landed on runway 26.
The flight instructor and the student pilot were practicing touch-and-go landings in the airplane. During the initial climb after the fourth landing, the flight instructor reported an emergency to air traffic control and indicated that he was going to return and land on a runway at the airport. During that transmission, a stall warning horn was sounding. The airplane then spun to the left and descended to impact in a marsh.The damage to the airplane was consistent with the airplane being in a left spin at impact, and the propeller displayed little damage, which is consistent with the engine not producing power at impact. The fuel selector handle was found positioned to the right main fuel tank; however, examination of the fuel selector's polymeric insert revealed that it had fractured and was in a position that provided openings of about 20% for the right main fuel tank inlet and for the engine outlet, instead of the 100% openings that would have been present with an intact polymeric insert. With only 20% of the normal fuel flow available, the airplane likely experienced a total loss of engine power due to fuel starvation. One of the pilots likely switched fuel tank positions during the previous touch-and-go landing, and the polymeric insert failed at that time. Examination of the wreckage did not reveal any other preimpact mechanical malfunctions.Metallurgical examination of the fuel selector valve revealed that the lower portion of the polymeric insert exhibited fracture features consistent with rotational ductile overstress. Abrasive wear was present on the outer portion of the insert due to contact with burs on the valve housing. The wear likely took place over a period during which the fuel selector handle would have been difficult to move and excessive force would have been required to move the handle from one position to another.Review of maintenance records did not reveal any prior anomalies with the fuel selector. The airplane maintenance manual contained instructions, applicable to 100-hour inspections, for the fuel selector to be inspected for condition, security, and operation. The instructions stated that, if the valve binds, sticks, or is otherwise difficult to operate, the fuel selector valve should be lubricated. However, about 5 months had passed since the most recent 100-hour inspection was completed on the airplane. During that time, the airplane had been operated about 78 hours. The investigation could not determine the condition Page 2 of 9 ERA17FA112of the fuel selector valve at the last 100-hour inspection.
The flight instructor of the helicopter reported that, about halfway through the flight, he "discovered that the throttle control was inoperative" and stuck in the high rpm setting. He turned the helicopter back to the departure airport and briefed his student on the situation. Upon being cleared to land, he executed a "running landing" and performed a go-around on the first try. On the second try, the skids made hard contact with the runway, and the helicopter came to a stop.A postaccident examination revealed that the helicopter had sustained substantial damage to the fuselage.The flight instructor reported that the throttle cable outer housing separated from the inner solid housing at the throttle linkage and that the internal wire could flex outside of the housing.
The pilot/owner of the turbine helicopter was practicing autorotations with a flight instructor. After completing several autorotations uneventfully, the instructor asked if he could perform one, and the pilot agreed. Near the flare at the end of the maneuver, the pilot heard the engine overrev, followed by an Nr (rotor speed) aural warning, followed by a fire warning light illumination on the instrument panel. After landing, the pilot exited the helicopter with a fire extinguisher and attempted to extinguish an engine fire.Review of data downloaded from a vehicle-engine multifunction display and digital engine control unit revealed that the first failure recorded during the flight indicated that the gas generator rotation speed (N1) reached an out-of-limit value. At that time, the fuel regulation was in mixed mode, as the collective twist grip throttle control was out of the "flight" detent and the pilot was manually controlling the throttle. A second failure was recorded 2 seconds later, which indicated that the free turbine rotation speed (N2) reached an out-of-limit value. The failure was triggered by the maximum recorded value of 545 rpm, which equated to a turbine speed (Nr) of 140%.The engine's freewheeling turbine was designed to separate turbine blades at 150% Nr in order to prevent the turbine disc separating at 170% Nr. It is likely that the flight instructor excessively opened the fuel metering unit via the twist grip throttle manual control, which resulted in an engine overspeed, turbine blade separation, and subsequent engine fire.
The private pilot was conducting a familiarization flight with the non-pilot-rated passenger, who had recently purchased the airplane. They flew to a nearby airport to practice touch-and-go landings. After completing about 15 landings, they proceeded to another airport to get fuel. About 5 minutes before reaching the airport, the passenger noticed that the fuel pressure gauge indicated 0 psi, but the engine was operating smoothly. The pilot turned on the electric fuel boost pump and the fuel pressure gauge returned to 5 psi. The boost pump remained on for the remainder of the flight. Upon arrival at the airport, a go-around was performed. The engine experienced a loss of power during the climb about 200 ft above ground level and he performed a forced landing to a field short of the runway. Postaccident fuel consumption calculations revealed that the airplane likely contained about 1 gallon of fuel at the time of the accident, which would have been unusable. Examination of the fuel tanks revealed less than 1 cup of fuel in the left tank and no fuel remaining in the right tank. The fuel spill observed at the accident site by first responders was likely the 1 gallon of unusable fuel from the right tank, because the right wing was separated at the fuselage and its fuel line was fractured. No anomalies were noted with the engine and the propeller blades did not show any rotational signatures. Although the pilot reported that he flew the airplane during the final approach and go-around, there were discrepancies in his statements that suggested that the non-pilot rated passenger was actually manipulating the airplane controls during the loss of engine power.
The flight instructor reported that, while performing maneuvers about 800 ft above the ground, a bird impacted the left wing. He added that he returned to the airport without further incident. A postaccident examination of the airplane revealed substantial damage to the left wing. The flight instructor reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.
The pilot of the tailwheel-equipped airplane reported that, during landing, as the tail came down, a "sizable gust weathervaned" the airplane to the left. He added that, he "made aggressive inputs to correct the direction" but was unsuccessful. He further added that, once the airplane veered off the runway and into the grass, he could feel the mains begin to sink into the soft ground. Subsequently, the airplane nosed over. The airplane sustained substantial damage to the right wing lift struts and empennage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. A review of recorded data from the automated weather observation station located on the airport revealed that, about 16 minutes after the accident, the wind was from 170° at 9 knots. The airplane landed on runway 18.