roccoangelella/AeroGraph huggingface dataset:
The purpose of the flight was for the pilot to gain some experience, with a pilot-rated passenger onboard, in his recently purchased airplane. The pilot reported that, after completing about 10 touch-and-go landings at a nearby airport, he flew the airplane back to his home airport for a full-stop landing. The pilot announced the he was entering a left downwind, reduced the speed, and lowered the landing gear. After turning to final approach, the pilot lowered the flaps and was concentrating on lining up the airplane on the runway centerline. The pilot-rated passenger stated that the airplane was lined up on the runway but that it seemed a little low. The passenger stated that, after passing over a tree line, the pilot surprised him by reducing the power rather than increasing it. Subsequently, the airplane descended into power lines and then impacted the ground and tumbled inverted. The pilot stated that he did not see the power lines nor that he was looking for any because they "had not been a factor" in his previous approaches.  The power lines were located about 1/4 mile from the airport. Evidence at the accident site revealed that the airplane had impacted the top two lines of a four-line power line. After the accident, the pilot stated that there were no mechanical issues with the airplane that would have precluded normal operation. It is likely that the pilot failed to adequately monitor the environment and to maintain sufficient altitude to clear the power lines.
After a preflight inspection revealed no anomalies, the private pilot departed on a local flight. Shortly after takeoff, he elected to return to the departure airport due to adverse weather nearby. He entered the airport traffic pattern and while on final approach with the flaps extended 30°, the airplane encountered a wind gust, which caused the airplane to balloon. The pilot executed a go-around and entered the traffic pattern for the same runway, but he only extended the flaps to 10°. He reported that the touchdown was soft and on the runway numbers. He then taxied to parking and secured the airplane. Surveillance video footage showed the pilot inspecting the propeller after disembarking. Postaccident examination of the airplane, which had not moved or been operated since being returned by the pilot, revealed damage to the propeller and firewall; therefore, it is likely that the damage was sustained during the pilot's landing due to an improper landing flare.
The private pilot was conducting a personal cross-country flight. Fuel records indicated that the pilot had purchased 9.56 gallons of fuel the day before the accident. A witness reported observing the pilot use fuel cans to add fuel to both airplane's fuel tanks. The witness saw the pilot taxi up and down the runway multiple times and subsequently depart; he then drove to the nearby airport (the pilot's intended destination) to pick up the pilot. When the pilot did not arrive, he reported the airplane missing. Responders tracked the emergency locator transmitter signal, and a helicopter pilot spotted the airplane in a field near a tree line.Upon examination, the propeller blades did not exhibit any chordwise abrasions or leading edge nicks, consistent with the engine not producing power at the time of impact. The fuel system was found intact except for a separated line near the left fuel tank. About 6 gallons of a blue-colored liquid consistent with the smell and color of aviation gasoline (avgas) was recovered from the right fuel tank. About 2 gallons of liquid consistent with avgas was recovered from the left fuel tank. Each fuel tank could hold 21 gallons of fuel, of which 2.5 gallons was unusable. There was some liquid consistent with avgas found in the carburetor bowl and in the firewall-mounted strainer bowl. All found and recovered liquid samples were tested for water contamination, and no water contamination was observed. Observed airplane damage was consistent with impact with trees and inverted impact with terrain.The fuel valve selector handle was found in the "right tank" position. However, no securing pin was installed in the selector handle, and during postaccident examination, pressurized air applied to the main fuel line at the firewall was observed discharging from the left tank's fuel line, which showed the selector valve fed the engine from the left tank. The engine operated normally during postaccident engine test runs. Based on the evidence, it is likely that the engine was starved of fuel when the fuel selector handle did not move the fuel selector valve to the desired position because the necessary securing pin was missing. The airplane's most recent annual inspection was completed about 8.5 years before the accident. The lack of routine maintenance on the airplane likely eliminated the necessary opportunities for the missing securing pin to be corrected.Page 2 of 9 CEN17FA085
The pilot reported that, during the landing roll in gusting crosswind conditions, the airplane veered off the runway to the left into the grass. During the runway excursion, the right wing impacted an airport sign, which resulted in substantial damage. After the airplane had stopped, the pilot taxied to the ramp without further incident. The pilot reported no preaccident mechanical malfunctions or failures 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 2 minutes before the accident, the wind was from 310° at 22 knots, gusting to 27 knots. The airplane landed on runway 1R.According to the Pilot's Operating Handbook for the accident airplane, the maximum demonstrated crosswind component for the airplane is 20 miles per hour/17.3 knots.
The pilot stated that after departure for the local flight, he maneuvered the airplane along the shoreline, and the airplane reached about 900 ft above ground level. The fuel pressure then dropped to zero, and the low-pressure light illuminated. The pilot switched fuel tanks and activated the fuel pump; however, the pressure remained at zero. The pilot attempted to restart the engine and switched tanks again, to no avail. He ditched the airplane in the bay, and the airplane became submerged after impact. After the airplane was recovered, the pilot removed the top wings, which revealed water in the fuel tanks. Due to the submersion of the airplane, it could not be determined if water was in the fuel tanks before the accident, and the fuel system could not be examined. The pilot also noticed that the ground wire on the electric pump was loose; however, it could not be determined if the loose wire was a result of impact. Thus, the reason for the loss of engine power could not be determined.
The flight instructor was demonstrating the emergency procedure for a full-authority digital engine control (FADEC) failure that would cause it to switch from auto to manual mode as part of the helicopter manufacturer's training program. The instructor stated that the helicopter was in a stable 5-ft hover when he was demonstrating the maneuver. To begin the demonstration, the flight instructor intentionally switched the FADEC to the manual mode. After about 10 seconds, the engine speed began to increase, which resulted in a corresponding increase in the main rotor speed. The instructor increased the collective control input in an attempt to control the engine and rotor speeds. The helicopter subsequently climbed and began to shake violently. The instructor initiated a descent for landing with an excessive descent rate, which resulted in damage to the landing skids and tailboom upon touchdown.The helicopter flight manual emergency procedure for a FADEC failure and the training program procedure for the FADEC manual mode demonstration both noted that the engine and rotor speeds must be maintained between 95% and 100% with the collective and throttle controls. The demonstration procedure also noted that the throttle control should be in the fly position when the FADEC is placed into manual mode. A review of engine data recovered from the FADEC indicated that the throttle was not in the fly position before beginning the demonstration, which likely resulted in a greater increase in engine and rotor speeds than would have been expected. The flight instructor did not promptly manage the increase in the engine and rotor speeds, which resulted in an inadvertent overspeed condition and subsequent airframe vibrations that prompted the need for an emergency landing.
The flight crew was departing the airport in winter weather conditions. The flight crew taxied to the runway and waited as another regional jet landed and cleared the runway. The captain of that jet reported on the common traffic advisory frequency that the braking action was nil and cautioned the accident flight crew to be careful because the runway was slick. The pilot flying reported that, as they taxied onto the runway, the wind was 40° right of runway heading at 10 kts with no gusts and the runway was slick. As the airplane was on the takeoff roll passing 60 kts, the pilot noticed a rising crosswind but maintained centerline. When the airplane was passing 80 kts, the flight crew was unable to maintain the airplane's track on the centerline with full right aileron deflection. The pilot attempted to rotate and lift off, but the airplane went into deep snow on the side of the runway. The pilot then reduced power to idle before going off the left side of the runway; the nose wheel collapsed, which resulted in substantial damage to the nose of the airplane and both engines. The flight crew reported no preimpact mechanical malfunctions or failures that would have precluded normal operation.
The No. 2 engine fan blade airfoil separation was caused by a low cycle fatigue crack that originated at the forward blade pin hole attachment tang due to insufficient residual stress (hoop stress) levels in the Ti-8-1-1 blade material. The fan blade had undergone a hot form repair following a bird strike incident in December 2007 to restore the blade profile. During the hot form repair process the blade was placed in a ceramic die and heated to 1150-1200oF to restore the blade geometry. The hot form process relieved the compressive residual stress layer in the fan blade and the layer was not properly restored with a lance peen/shot peen step as called out in the GE Standard Repair Manual. There was visual evidence of 100% lance peen/shot peen coverage on the fan blade attachment pin holes surfaces that was identified during the materials lab examination, but the peen marks were most likely formed during the original fan blade manufacturing process.When the fan blade airfoil separated during the incident it was contained by the engine fan case containment system. The fan blade impact with the fan case containment system resulted in a bulge in the Kevlar wrap that damaged the attaching hardware at the fan cowl flanges, and the cowl subsequently separated when exposed to the jet stream. When the fan cowls separated from the engine they impacted the thrust reverser translating cowl and core cowl and resulted in gouging and surface buckling.The fan blade airfoil separation caused a fan imbalance that led to high No. 2 engine vibration levels. The high vibration levels caused the engine transition case to LPT flange separation, AGB housing fracture, and starter damage.
The airline transport pilot was conducting a local flight and had been airborne for about 40 minutes when he heard a "bang;" the engine then began to shake and experienced a total loss of power. The pilot conducted a forced landing, and the airplane impacted a stand of pine trees before coming to rest. An onsite examination of the airplane found oil on the underside of the airframe and the back of the engine, with no oil showing on the dipstick. Additionally, the nuts securing the engine vacuum pump appeared loose.Disassembly of the engine found only a small amount of oil in the engine sump as well as numerous metal pieces. The crankshaft No. 5 rod journal exhibited heat damage, and the connecting rod had separated from the journal, consistent with the lack of oil lubrication. A review of the engine's maintenance records revealed that the engine had accumulated about 263 hours since overhaul. The records also indicated the vacuum pump was replaced and had accumulated 1.19 hours at the time of the accident. The accident is consistent with the loss of engine oil from the vacuum pump drive, likely as a result of maintenance personnel improperly securing the vacuum pump following replacement.
The commercial pilot was taking his cousin for an airplane ride. During takeoff, the airplane remained in ground effect until it reached a point near or past the departure end of the runway, and then it entered a right climbing turn. At an altitude of about 100 to 150 ft above ground level, the airplane entered a left turn with a bank angle that increased to about 80&deg; to 90&deg; before the airplane descended and impacted the ground. Wreckage distribution and ground scarring were consistent with a nose-down, low-speed, impact. It is likely that the excessive left bank angle resulted in the airplane exceeding its critical angle of attack and experiencing an aerodynamic stall at an altitude too low for recovery. Postaccident examination of the engine and airframe revealed no anomalies that would have precluded normal airplane operation.
The commercial pilot reported that, after departing for the cross-country, cargo flight, he retracted the landing gear and heard a "thud" sound. Subsequently, the main landing gear (MLG) "unsafe" light illuminated, and the left MLG light remained illuminated green, indicating that it was still extended despite the landing gear handle being in the retracted position. The pilot returned to the departure airport, and during touchdown, the right MLG collapsed, which resulted in substantial damage to the right aileron and right wing spar.During the postaccident examination of the landing gear, the left MLG actuator's piston rod was found fractured. Metallurgical examination of the piston rod revealed that the rod had failed in its threaded section due to fatigue cracking over about 60% of the cross-section. Contact wear was observed on the faying surface of the retaining nut and piston head and the shoulder of the piston rod. These signatures were consistent with the nut not being tight enough to mitigate sliding of the piston head relative to the piston rod and retaining nut. It could not be determined if the manufacturer required a specific torque to be applied to the nut during assembly. Based on the evidence, it is likely that inadequate torque on the nut reduced the preload on the threaded section of the piston rod and contributed to premature fatigue crack propagation in the rod and its eventual failure. The failure of the piston rod allowed hydraulic fluid to pass freely from the down-side to the up-side of the piston, which prevented the hydraulic system from producing pressure to control the MLG's position.
The airplane experienced a gear-up landing after the private pilot was unable to extend the landing gear. Postaccident examination of the landing gear motor revealed that the sector gear teeth were partially sheared and were bound with the worm gear teeth, resulting in interference. Once the gear was turned past the sheared area, the assembly functioned with no anomalies. Review of maintenance logs revealed that the most recent annual inspection, which included the landing gear system, was completed about 6 months before the accident with no anomalies noted.
The student pilot reported that, while practicing 180° autorotations about 500 ft above ground level, the flight instructor reduced the throttle, and the student pilot lowered the collective while simultaneously applying aft cyclic and right pedal. He added that the helicopter began to "dive," and the flight instructor took control of the helicopter. The flight instructor reported that he initiated a go-around by applying aft cyclic and raising the collective, but they "continued in a rapid descent." The flight instructor added that at "roughly fifty feet, [he] flared harder to attempt a next-to-final arrest." The helicopter landed hard, the skids collapsed, and the main rotor blades severed the tailboom. The helicopter slid about 300 ft down the runway toward the right; the right skid stuck into the grass, and the helicopter rotated clockwise about the right skid, tipped onto the nose, and rolled to the left.The flight instructor reported that he and the student pilot had performed about 10 to 12 practice autorotations before the accident.The helicopter sustained substantial damage to the fuselage.The flight instructor reported that there were no preaccident mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.Robinson Helicopter Company published Safety Notice, SN-38, dated July 2003 and revised in October 2004, which addressed training accidents caused by practice autorotations and stated, in part:        A high percentage of training accidents occur after many consecutive autorotations. To maintain instructor focus and minimize student fatigue, limit practice to no more than 3 or 4 consecutive autorotations.Page 2 of 6 GAA17CA112The Federal Aviation Administration's (FAA) Helicopter Flying Handbook, FAA-H-8083-21A, dated 2012, addressed tailboom strikes during autorotations and stated, in part:         A power recovery can be made during training in lieu of a full touchdown landing. Refer to the section on power recovery for the correct technique. After the helicopter has come to a complete stop after touchdown, lower the collective pitch to the full-down position. Do not try to stop the forward ground run with aft cyclic, as the main rotor blades can strike the tail boom. Rather, by lowering the collective slightly during the ground run, more weight is placed on the undercarriage, slowing the helicopter.One common error is holding the helicopter off the surface versus cushioning the helicopter on to the surface during an autorotation. Holding the helicopter in the air by using all of the rotor rpm potential energy usually causes the helicopter to have a hard landing, which results in the blades flexing down and contacting the tail boom. The rotor rpm should be used to cushion the helicopter on to the surface for a controlled, smooth landing instead of allowing the helicopter to drop the last few inches.
The pilot of the tailwheel-equipped airplane reported that he attempted to transition a mountain ridge after he had completed an aerial application. He added that he began to climb to a safe altitude in rising terrain but realized that it was going to be "close to clear" the mountain top. He attempted to turn to the left but noted that the terrain would not allow him to do so. He continued straight ahead and impacted the mountain top about 10 ft from the crest. The airplane sustained substantial damage to both wings and the fuselage.The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.
According to the pilot in the tailwheel-equipped airplane, during a low pass to evaluate the snow-covered runway, the airplane descended to 4 ft above ground level. The airplane encountered a crosswind from the left, and the pilot accomplished a "slip to remain over the runway." However, the airplane descended, and the left main landing gear struck a snow berm and the airplane struck the runway and nosed over. Substantial damage was sustained to both wings, the rudder, and the horizontal stabilizer.The pilot asserted that he should have practiced what he teaches his students and stayed 300 ft above airports when performing a fly-over.The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.
The private pilot, who was the owner and builder of the experimental amateur-built airplane, and a commercial pilot departed on a local flight and performed three touch-and-go practice takeoffs and landings. During the fourth takeoff, after reaching about 300 ft above the ground, the engine experienced a total loss of power. The airplane made a right turn and collided with terrain about 1,650 ft from the end of the runway. The single-engine airplane was constructed about 7 years before the accident, at which time the private pilot installed a newly-overhauled engine. The airplane had accrued about 100 total hours of time in service. During postaccident examination, the engine would not start but was found to operate normally when a different fuel servo was installed.The Bendix fuel servo, manufactured in 1977, was designed to meter fuel in relation to the volume of air being consumed by the engine. The metering is accomplished by air and fuel diaphragms inside the unit that are connected by a valve stem that has a regulator ball affixed at its end. A pressure differential across the air diaphragm results in the regulator ball unseating and providing the engine with more fuel. Complete disassembly of the accident fuel servo revealed that the regulator stem was separated from the regulator ball, which would prevent the ball from being able to unseat and would subsequently block fuel from entering the engine, resulting in fuel starvation.The servo manufacturer stated that the servo's internal components appeared to be original, although those components were required to be replaced every 12 years. There were no maintenance records pertaining to the servo, but its appearance indicated it was likely never overhauled. The maintenance entry for the engine overhaul noted that the airplane was equipped with a "serviceable fuel servo," which, according to a representative from the maintenance facility that performed the overhaul, was likely determined by an engine test run. Because the airframe and engine were classified as amateur-built experimental, the overhaul criteria are not required for airworthiness; however, it is likely that the failure of the regulator valve stem and ball would not have occurred if the servo components had been replaced in accordance with manufacturer specifications. Page 2 of 12 WPR17LA054