Private

The pilot was performing a personal cross-country flight. While en route to the intended destination, the pilot contacted air traffic control to report that the airplane was having a fuel pump issue and requested to divert to the nearest airport. The pilot stated that the request was only precautionary and did not declare an emergency during the flight; he provided no further information about the fuel pump. As the airplane approached the diversion airport, witnesses observed the airplane flying low and rolling to the left just before impacting terrain, after which a postcrash fire ensued. An examination of the airframe revealed no preimpact mechanical malfunctions or failures that would have precluded normal operation. A postaccident examination and review of recorded data indicated that the left engine was secured and in the feather position, and that the right engine was operating at a high RPM setting. The left engine-driven fuel pump was found fractured. Further examination of the fuel pump revealed fatigue failure of the pressure relief valve. The fatigue failure initiated in upward bending on one side of the valve disk and progressed around both sides of the valve stem. As the cracks grew, the stem separated from the disk on one side and began to tilt in relation to the disk and the valve guide due to the non-symmetric support, which caused the lower end of the stem to rub against the valve guide, creating wear marks. The increasing stem tilt would have impinged against the valve guide, and the valve might have begun to stick in the closed position. If the valve were stuck in the closed position, it would not be able to open, and the outlet fuel pressure could rise above the set point pressure. Because the pump was driven by the engine, there would not be a way for the pilot to shut it off, disconnect it, or bypass it. Instead, the fuel pressure would continue to rise until the valve were to unstick. Thus, the pilot was likely experiencing variable fuel pressure as the valve became stuck and unstuck. Examination of the spring seat and the diaphragm plate, which were in contact with each other in the fuel pump assembly, revealed wear marks on the surface of each component, with one mark on the diaphragm plate and two wear marks on the spring seat. The two wear marks on the spring seat were distinct features separated by material with no wear indications in between. The only way that these wear marks could have occurred were if the spring seat was separated from the diaphragm plate and reinstalled in a different orientation. Thus, it is likely that the pilot had encountered a fuel pump problem before the accident flight and that someone tried to troubleshoot the problem. The last radar data point indicated that the airplane was traveling at a groundspeed of about 98 knots, and had passed north of the airport, traveling to the southwest. The minimum control speed for the airplane with single-engine operation was 88 knots. However, it is likely that if the pilot initiated a left turn back toward the airport, that the right engine torque and the 14 knot wind with gusts to 24 knots would have necessitated a higher speed. Because appropriate control inputs and airspeed were not maintained, the airplane rolled in the direction of the feathered engine (due to the left fuel pump problem), resulting in a loss of control. The pilot's toxicology report was positive for cetirizine, sumatriptan, gabapentin, topiramate, and duloxetine. All of these drugs act in the central nervous system and can be impairing alone or in combination. Although this investigation could not determine the reason(s) for the pilot's use of these drugs, they are commonly used to treat chronic pain syndromes or seizures. It is likely that the pilot was experiencing some impairment because of multiple impairing medications and was unable to successfully respond to the in-flight urgent situation and safely land the airplane.

The pilot landed the seaplane into an easterly wind, then noticed that the surface wind was greater than forecast. Unable to taxi to the beaching location, he elected to return to his destination. He maneuvered the airplane into the wind and applied takeoff power. He described the takeoff run as "bumpy" and the water conditions as "rough." The pilot reported that the left float departed the airplane at rotation speed, and the airplane subsequently nosed into the water. The pilot and passengers were assisted by a nearby vessel and the airplane subsequently sank into 50 ft of water. Inclement sea and wind conditions prevented recovery of the wreckage for 52 days, and the wreckage was stored outside for an additional 13 days before recovery by the salvage company. Extensive saltwater corrosion prevented metallurgical examination of the landing gear components; however, no indication of a preexisting mechanical malfunction or failure was found.

The pilot began the takeoff roll in visual meteorological conditions. The airplane was airborne about 1,300 ft down the runway, which was about 75% of the normal ground roll distance for the airplane’s weight and the takeoff environment. About 2 seconds after rotation, the airplane rolled left. Three seconds later, the airplane had reached an altitude of about 80 ft above ground level and was in a 90° left bank. The nose then dropped as the airplane rolled inverted and struck the ground in a right-wing-low, nose-down attitude. The airplane was destroyed. Postaccident examination did not reveal any anomalies with the airframe or engines that would have precluded normal operation. The landing gear, flap, and trim positions were appropriate for takeoff and flight control continuity was confirmed. The symmetry of damage between both propeller assemblies indicated that both engines were producing equal and high amounts of power at impact. The autopsy revealed no natural disease was present that could pose a significant hazard to flight safety. Review of surveillance video footage from before the accident revealed that the elevator was in the almost full nose-up (or trailing edge up) position during the taxi and the beginning of the takeoff roll. Surveillance footage also showed that the pilot did not perform a preflight inspection of the airplane or control check before the accident flight. According to the pilot’s friend who was also in the hangar, as the accident pilot was pushing the airplane back into his hangar on the night before the accident, he manipulated and locked the elevator in the trailing edge up position to clear an obstacle in the hangar. However, no evidence of an installed elevator control lock was found in the cabin after the accident. The loss of control during takeoff was likely due to the pilot’s use of an unapproved elevator control lock device. Despite video evidence of the elevator locked in the trailing edge up position before the accident, an examination revealed no evidence of an installed control lock in the cabin. Therefore, during the night before the accident, the pilot likely placed an unapproved object between the elevator balance weight and the trailing edge of the horizontal stabilizer to lock the elevator in the trailing edge up position. The loss of control was also due to the pilot’s failure to correctly position the elevator before takeoff. The pilot’s friend at the hangar also reported that the pilot was running about one hour late; the night before, he was trying to troubleshoot an electrical issue in the airplane that caused a circuit breaker to keep tripping, which may have become a distraction to the pilot. The pilot had the opportunity to detect his error in not freeing the elevator both before boarding the airplane and again while in the airplane, either via a control check or detecting an anomalous aft position of the yoke. The pilot directed his attention to the arrival of a motorbike in the hangar alley shortly after he pulled the airplane out of the hangar, which likely distracted the pilot and further delayed his departure. He did not conduct a preflight inspection of the airplane or control check before the accident flight, due either to distraction or time pressure.

Two instrument-rated commercial pilots and one passenger were conducting a cross-country flight in instrument meteorological conditions when they began discussing an electrical malfunction; they then reported the electrical problem to air traffic control. The airplane subsequently made a descending right turn and impacted wooded terrain at a high speed. Most components of the airplane were highly fragmented, impact damaged, and unidentifiable. Based on the limited discussion of the electrical problem on the cockpit voice recorder and the damage to the airplane, it was not possible to determine the specific nature of the electrical malfunction the airplane may have experienced. While it was not possible to determine which systems were impacted by the electrical malfunction, it is possible the flight instruments were affected. The airplane's descending, turning, flight path before impact is consistent with a system malfunction that either directly or indirectly (through a diversion of attention) led to the pilot's loss of awareness of the airplane's performance in instrument meteorological conditions and subsequent loss of control of the airplane.

The two commercial pilots were conducting a personal, cross-country flight. A video surveillance camera at the airport captured their airplane’s approach. Review of the video revealed that, as the airplane approached the approach end of the landing runway, it began to climb, rolled left, became inverted, and then impacted terrain. The left thrust reverser (T/R) was found open and unlatched at the accident site. An asymmetric deployment of the left T/R would have resulted in a left roll/yaw. The lack of an airworthy and operable cockpit voice recorder, which was required for the flight, precluded identifying which pilot was performing pilot flying duties, as well as other crew actions and background noises, that would have facilitated the investigation. Postaccident examination of the airplane revealed that it was not equipped, nor was required to be equipped, with a nose landing gear (NLG) ground contact switch intended to preclude inflight operation of the thrust reverser (T/R). The left T/R door was found unlatched and open, and the right T/R door was found closed and latched. Further, electrical testing of the T/R left and right stow microswitches within the cockpit throttle quadrant revealed that the left stow microswitch did not operate within design specifications. Disassembly of the left and right stow microswitches revealed evidence of arc wear due to aging. Based on this information, it is likely that the airplane’s lack of an NLG ground contact switch and the age-related failure of the stow microswitches resulted in an asymmetric T/R deployment while on approach and a subsequent loss of airplane control. Also, there were additional T/R system components that were found to unairworthy that would have affected the control of the T/R system. Operational testing of the T/R system could not be performed due to the damage the airplane incurred during the accident. Toxicology testing results of the pilot’s specimens indicated that the pilot had taken diazepam, which is considered impairing at certain levels. However, the detected amounts of both diazepam and its metabolite nordiazepam were at subtherapeutic levels, and given the long half-life of these compounds, it appears that the medication was taken several days before the accident; therefore, it is unlikely that the pilot was impaired at the time of the accident and thus that his use of diazepam was a not factor in the accident.

The pilot departed on a short cross-country flight in the twin-engine airplane. Instrument meteorological conditions (IMC) were present at the time. While en route at an altitude of 3,000 ft mean sea level, the pilot reported that the airplane was "picking up icing" and that he needed to "pick up speed." The controller then cleared the pilot to descend, then to climb, in order to exit the icing conditions; shortly thereafter, the controller issued a low altitude alert. The pilot indicated that he was climbing; radar and radio contact with the airplane were lost shortly thereafter. The airplane impacted a field about 7 miles short of the destination airport. Examination of the airplane was limited due to the fragmentation of the wreckage; however, no pre-impact anomalies were noted during the airframe and engine examinations. Extensive damage to the pitot static and deicing systems precluded functional testing of the two systems. A review of data recorded from onboard avionics units indicated that, about the time the pilot reported to the controller that the airplane was accumulating ice, the airplane's indicated airspeed had begun to diverge from its ground speed as calculated by position data. However, several minutes later, the indicated airspeed was zero while the ground speed remained fairly constant. It is likely that this airspeed indication was the result of icing of the airplane's pitot probe. During the final 2 minutes of flight, the airplane was in a left turn and the pilot received several "SINK RATE" and "PULL UP PULL UP" annunciations as the airplane conducted a series of climbs and descents during which its ground speed (and likely, airspeed) reached and/or exceeded the airplane's maneuvering and maximum structural cruising speeds. It is likely that the pilot became distracted by the erroneous airspeed indication due to icing of the pitot probe and subsequently lost control while maneuvering.

The instrument-rated private pilot and passenger departed into instrument meteorological conditions with a 600-ft cloud ceiling in an airplane that was about 550 lbs over gross weight. Air traffic control data showed the airplane in a climbing left turn that continued beyond the assigned heading. After reaching 1,400 ft msl, the airplane continued turning left and its altitude and speed began to vary. The airplane continued in a left spiral, completing more than two full circles, then decelerated in a right turn and rapidly descended until impact with terrain. Examination of the flight control system revealed no evidence of mechanical malfunctions and downloaded engine data indicated normal engine operation. Downloaded data from the autopilot system revealed three in-flight error codes. The first error code, which likely occurred about 1 minute after takeoff, would have resulted in the autopilot, if it was engaged at the time, disengaging. The subsequent error codes likely occurred during the erratic flight profile, with the autopilot disengaged. Before the accident flight, the pilot had informed a mechanic, who is also a pilot, of intermittent issues with the autopilot system and that these issues were unresolved. The mechanic had flown with the accident pilot previously and assessed his instrument flying skills as weak. The flight instructor who provided initial flight training for the turbine engine transition stated the pilot's instrument flying proficiency was poor when he was hand flying the airplane. Toxicology testing revealed that the pilot had used marijuana, and his girlfriend stated the pilot would take a marijuana gummy before bedtime to sleep more soundly. However, given that no psychoactive compounds were found in blood specimens, it is unlikely that the pilot was impaired at the time of the accident. The instrument conditions at the time of the accident, the airplane's erratic flightpath, and the pilot's reported lack of instrument proficiency when flying by hand support the likelihood that the pilot experienced spatial disorientation sometime after takeoff. In addition, given the reports of the intermittently malfunctioning autopilot that had not been fixed, it is likely the pilot experienced an increased workload during a critical phase of flight that, in combination with spatial disorientation, led to the pilot's loss of airplane control.

The pilot was conducting a personal cross-country flight with one passenger in his twin-engine airplane. There was no record that the pilot received a weather briefing before the accident flight. While en route to the destination, the pilot was in contact with air traffic control and received visual flight rules flightfollowing services. About 18 miles from the destination airport, the radar service was terminated, as is typical in this geographic region due to insufficient radio and radar coverage below 7,000 ft. The airplane was heading northeast at 4,900 ft mean sea level (msl) (about 2,200 ft above ground level [agl]). About 4 minutes later, radar coverage resumed, and the airplane was 6 miles west of the airport at 4,100 ft msl (1,400 ft agl) and climbing to the north. The airplane climbed through 6,000 ft msl (3,300 ft agl), then began a shallow left turn and climbed to 6,600 ft msl (3,800 ft agl), then began to descend while continuing the shallow left turn ; the last radar data point showed the airplane was about 20 nm northwest of the airport, 5,100 ft msl (2,350 ft agl) on a southwest heading. The final recorded data was about 13 miles northwest of the accident site. A witness near the destination airport heard the pilot on the radio. He reported that the pilot asked about the cloud height and the witness responded that the clouds were 800 to 1,000 ft agl. In his final radio call, the pilot told the witness, "Ok, see you in a little bit." The witness did not see the airplane in the air. The airplane impacted terrain in a slightly nose-low and wings-level attitude with no evidence of forward movement, and a postimpact fire destroyed a majority of the wreckage. The damage to the airplane was consistent with a relatively flat spin to the left at the time of impact. A postaccident examination did not reveal any preimpact mechanical malfunctions or anomalies that would have precluded normal operation. A detailed examination of the cockpit instruments and other portions of the wreckage was not possible due to the fire damage. A cold front had advanced from the northeast and instrument meteorological conditions prevailed across the region surrounding the accident site and the destination airport; the cloud ceilings were 400 ft to 900 ft above ground level. The airplane likely experienced wind shear below 3,000 ft, and there was likely icing in the clouds. While moderate icing conditions were forecast for the accident site, about the time of the accident, investigators were unable to determine the amount and severity of icing the flight may have experienced. The weather conditions had deteriorated over the previous 1 to 2 hours. The conditions at the destination airport had been clear about 2 hours before accident, and visual flight rules conditions about 1 hour before accident, when the pilot departed. Based on the available evidence it is likely that the pilot was unable to maintain control of the airplane, which resulted in an aerodynamic stall and spin into terrain.

The commercial pilot departed for a cross-country, personal flight with no flight plan filed. No evidence was found that the pilot received a preflight weather briefing; therefore, it could not be determined if he checked or received any weather information before or during the accident flight. Visual meteorological conditions existed at the departure airport; however, during the departure climb, the weather transitioned to instrument meteorological conditions (IMC) with precipitation, microburst, and rain showers over the accident area. During the takeoff clearance, the air traffic controller cautioned the pilot about deteriorating weather conditions about 4 miles east of the airport. Radar data showed that, about 5 1/2 minutes after takeoff, the airplane had climbed to about 7,800 ft above ground level before it started a rapid descending right turn and subsequently impacted the ground about 9.6 miles east of the departure airport. Recorded data from the airplane’s Appareo Stratus 2S (portable ADS-B receiver and attitude heading and reference system) revealed that, during the last 15 seconds of the flight, the airplane’s attitude changed erratically with the pitch angle fluctuating between 45° nose-down and 75°nose-up, and the bank angle fluctuating between 170° left and 150° right while descending from 5,500 to 500 ft above ground level, indicative of a loss of airplane control shortly after the airplane entered the clouds. Several witnesses located near the accident site reported seeing the airplane exit the clouds at a high descent rate, followed by airplane parts breaking off. One witness reported that he saw the airplane exit the overcast cloud layer with a nose down pitch of about 60°and remain in that attitude for about 4 to 5 seconds “before initiating a high-speed dive recovery,” at the bottom of which, the airplane began to roll right as the left horizontal stabilizer separated from the airplane, immediately followed by the remaining empennage. He added that the left wing then appeared to shear off near the left engine, followed by the wing igniting. An outdoor home security camera, located about 0.5 mile north-northwest of the accident location, captured the airplane exiting the clouds trailing black smoke and then igniting. Examination of the debris field, airplane component damage patterns, and the fracture surfaces of separated parts revealed that both wings and the one-piece horizontal stabilizer and elevators were separated from the empennage in flight due to overstress, which resulted from excessive air loads. Although the airplane was equipped with an autopilot, the erratic variations in heading and altitude during the last 15 seconds of the flight indicated that the pilot was likely hand-flying the airplane; therefore, he likely induced the excessive air loads while attempting to regain airplane control. Conditions conducive to the development of spatial orientation existed around the time of the in-flight breakup, including restricted visibility and the flight entering IMC. The flight track data was consistent with the known effects of spatial disorientation and a resultant loss of airplane control. Therefore, the pilot likely lost airplane control after inadvertently entering IMC due to spatial disorientation, which resulted in the exceedance of the airplane’s design stress limits and subsequent in-flight breakup. Contributing to accident was the pilot’s improper decision to conduct the flight under visual flight rules despite encountering IMC and continuing the flight when the conditions deteriorated. Toxicology testing on specimens from the pilot detected the presence of delta-9-tetrahydrocanninol (THC) in heart blood, which indicated that the pilot had used marijuana at some point before the flight. Although there is no direct relationship between postmortem blood levels and antemortem effects from THC, it does undergo postmortem redistribution. Therefore, the antemortem THC level was likely lower than detected postmortem level due to postmortem redistribution from use of marijuana days previously, and it is unlikely that the pilot’s use of marijuana contributed to his poor decision-making the day of the accident. The toxicology testing also detected 67 ng/mL of the sedating antihistamine diphenhydramine. Generally, diphenhydramine is expected to cause sedating effects between 25 to 1,120 ng/mL. However, diphenhydramine undergoes postmortem redistribution, and the postmortem heart blood level may increase by about three times. Therefore, the antemortem level of diphenhydramine was likely at or below the lowest level expected to cause significant effects, and thus it is unlikely that the pilot’s use of diphenhydramine contributed to the accident.

The pilot departed on an instrument flight rules flight into instrument meteorological conditions (IMC). Radar data indicated that the airplane entered a left turn after takeoff, consistent with the pilot's instrument clearance. As the airplane climbed to an altitude about 2,410 ft above ground level, its rate of climb increased from about 3,500 ft per minute to 9,600 ft per minute, the stick shaker activated, and the airplane decelerated to about 75 knots. The airplane then entered a descending right turn and rolled inverted before impacting terrain about 1 mile from the airport. All major components of the airplane were located at the accident site, and examination of the wreckage revealed no anomalies with the airplane that would have precluded normal operation. The weather conditions about the time of the accident included an overcast cloud ceiling about 600 ft above ground level. It is likely that the pilot became spatially disoriented after entering the cloud layer, which resulted in the airplane's high rate of climb, rapid loss of airspeed, and a likely aerodynamic stall. The steep descending right turn, the airplane's roll to an inverted attitude, and the high-energy impact are also consistent with a loss of control due to spatial disorientation.