Plain, Valley

The commercial pilot of the multi-engine airplane was conducting an instrument flight rules cross-country flight at night. The pilot checked in with air traffic control at a cruise altitude about 10,000 ft mean sea level (msl). About 31 minutes later, the pilot reported that he saw lightning off the airplane's left wing. The controller advised the pilot that the weather appeared to be about 35 to 40 miles away and that the airplane should be well clear of it. The pilot responded to the controller that he had onboard weather radar and agreed that they would fly clear of the weather. There were no further communications from the pilot. About 4 minutes later, radar information showed the airplane at 10,400 ft msl. About 1 minute later, radar showed the airplane in a descending right turn at 9,400 ft. Radar contact was lost shortly thereafter. The distribution of the wreckage, which was scattered in an area with about a 1/4-mile radius, was consistent with an in-flight breakup. The left horizontal stabilizer and significant portions of both left and right elevators and their respective trim tabs were not found. Of the available components for examination, no pre-impact airframe structural anomalies were found. Examination of the engines and turbochargers did not reveal any pre-impact anomalies. Examination of the propellers showed evidence of rotation at impact and no pre-impact anomalies. Review of weather information indicated that no convection or thunderstorms were coincident with or near the airplane's route of flight, and the nearest convective activity was located about 25 miles west of the accident site. Autopsy and toxicology testing revealed no evidence of pilot impairment or incapacitation. Given the lack of radar information after the airplane passed through 9,400 ft, it is likely that it entered a rapid descent during which it exceeded its design stress limitations, which resulted in the in-flight breakup; however, based on the available information, the event that precipitated the descent and loss of control could not be determined.

The crew was engaged in a spraying mission over rice paddy fields in the region of Kiliya, Odessa. While completing the 18th sortie of the day, flying at a height of 50 metres and at a speed of 140-150 km/h, the engine failed. The crew attempted an emergency landing when the aircraft hit obstacles and trees and crashed. The captain escaped unhurt while the copilot was slightly injured. The aircraft was damaged beyond repair.

On 16 June 2017, a Pacific Aerospace Ltd FU24 Stallion, registered VH-EUO (EUO), was conducting aerial agricultural operations from a private airstrip at Redhill, 36 km north-north-east of Bathurst, New South Wales (NSW). The operations planned for that day involved the aerial application of fertiliser on three properties in the Upper Turon area of NSW. At about 0700 Eastern Standard Time on the morning of the accident, the pilot and loader drove to Bathurst Airport to fill the fuel tanker and then continued to the worksite at the Redhill airstrip in the Upper Turon area, arriving at about 0830. Work on the first property started at about 0900, with the first flight of the day commencing at 0920. Work on the first property continued until 1350 with two refuelling stops at 1048 and 1250. Approximately 40 tonnes of fertiliser was applied on the first job. In preparation for the second job, fertiliser and seed were loaded into the aircraft and maps of the second job area were passed to the pilot. At 1357, the aircraft took off for the first flight of the second job. The aircraft returned to reload, and at 1405 the aircraft took off for the second flight. A short time later, at 14:06:59, recorded flight data from the aircraft ceased. When the aircraft did not return as expected, the loader radioed the pilot. When the loader could not raise the pilot on the radio, he became concerned and drove his vehicle down the airstrip to see if the aircraft had experienced a problem on the initial climb. Finding no sign of the aircraft, he returned to the load site, while continuing to call the pilot on the radio. He then drove to the application area to search for the aircraft before returning to the load site. With no sign of the aircraft, the loader called emergency services to raise the alarm. By about 1500, police had arrived on site and a ground search commenced. A police helicopter also joined the search, which was eventually called off due to low light. The next morning, at about 0630, the search recommenced and included NSW Police State Emergency Service personnel, and local volunteers. At about 0757, the wreckage of the aircraft was found in dense bush on the side of a hill to the east of the application area. The pilot was found deceased in the aircraft. The aircraft was found approximately 17 hours after the last recorded flight data and there were no witnesses to the accident.

The twin engine airplane departed El Palomar Airport at 1604LT on a training flight, carrying one passenger and two pilots. While descending to Buenos Aires-Ezeiza-Ministro Pistarini Airport, the right engine failed. The crew was unable to restart the engine and to maintain a safe altitude, so he attempted an emergency landing when the aircraft crashed in an open field located 24 km from the airport, bursting into flames. All three occupants were injured and the aircraft was partially destroyed by fire.

The commercial pilot departed on a planned 1-hour cargo cross-country flight in the autopilot-equipped airplane. About 3 minutes after departure, the controller instructed the pilot to fly direct to the destination airport at 2,000 ft mean sea level (msl). The pilot acknowledged the clearance, and there were no further radio transmissions from the airplane. The airplane continued flying past the destination airport in straight-and-level flight at 2,100 ft msl, consistent with the airplane operating under autopilot control, until it was about 100 miles beyond the destination airport. A witness near the accident site watched the airplane fly over at a low altitude, heard three "pops" come from the airplane, and then saw it bank to the left and begin to descend. The airplane continued in the descending left turn until he lost sight of it as it dropped below the horizon. The airplane impacted trees in about a 45° left bank and a level pitch attitude and came to rest in a heavily wooded area. The airplane sustained extensive thermal damage from a postcrash fire; however, examination of the remaining portions of the airframe, flight controls, engines, and engine accessories revealed no evidence of preimpact failure or malfunction. The fuel selector valves were found on the outboard tanks, which was in accordance with the normal cruise procedures in the pilot's operating handbook. Calculations based on the airplane's flight records and the fuel consumption information in the engine manual indicated that, at departure, the outboard tanks of the airplane contained sufficient fuel for about 1 hour 10 minutes of flight. The airplane had been flying for about 1 hour 15 minutes when the accident occurred. Therefore, it is likely that the fuel in the outboard tanks was exhausted; without pilot action to switch fuel tanks, the engines lost power as a result of fuel starvation, and the airplane descended and impacted trees and terrain. The overflight of the intended destination and the subsequent loss of engine power due to fuel starvation are indicative of pilot incapacitation. The pilot's autopsy identified no significant natural disease:however, the examination was limited by the severity of damage to the body. Further, there are a number of conditions, including cardiac arrhythmias, seizures, or other causes of loss of consciousness, that could incapacitate a pilot and leave no evidence at autopsy. The pilot's toxicology results indicated that the pilot had used marijuana/tetrahydrocannabinol (THC) at some point before the accident. THC can impair judgment, but it does not cause incapacitation; therefore, the circumstances of this accident are not consistent with impairment from THC, and, the pilot's THC use likely did not contribute to this accident. The reason for the pilot's incapacitation could not be determined.

The twin engine aircraft departed Cali-Alfonso Bonilla Aragón Airport in the morning on a flight to Tolú, carrying seven passengers and one pilot. After takeoff from Tolú, the pilot decided to position to Montería-Los Garzones Airport. Shortly after takeoff, the pilot encountered engine problems and elected to make an emergency landing in a pasture. Upon landing, the right wing collided with obstacles then the nose gear collapsed and the aircraft came to rest near Purísima de la Concepción, about 10 km east of Tolú. The pilot was uninjured and the aircraft was damaged beyond repair.

The commercial pilot and three passengers departed on an instrument flight rules crosscountry flight. While on approach to the destination airport, the pilot indicated to the air traffic controller that the airplane was passing through areas of moderate-to-extreme precipitation. After clearing the airplane for the approach, the controller noted that the airplane descended below its assigned altitude; the controller issued a low altitude alert, but no response was received from the pilot. The airplane subsequently impacted terrain in a level attitude about 12 miles from the airport. Examination of the airframe, engine, and system components revealed no evidence of preimpact mechanical malfunction that would have precluded normal operation. An area of disturbed, flattened, tall grass was located about 450 ft southwest of the accident site. Based on the images of the grass, the National Weather Service estimated that it would take greater than 35 knots of wind to lay over tall grass as the images indicated, and that a downburst/microburst event could not be ruled out. A downburst is an intense downdraft that creates strong, often damaging winds. About 6 hours before the flight, the pilot obtained weather information through a mobile application. Review of weather data indicated the presence of strong winds, heavy precipitation, turbulence, and low-level wind shear (LLWS) in the area at the time of arrival, which was reflected in the information the pilot received. Given the weather conditions, it is likely that the airplane encountered an intense downdraft, or downburst, which would have resulted in a sudden, major change in wind velocity. The airplane was on approach for landing at the time and was particularly susceptible to this hazardous condition given its lower altitude and slower airspeed. The downburst likely exceeded the climb performance capabilities of the airplane and resulted in a subsequent descent into terrain. It is unknown if the accident pilot checked or received additional weather information before or during the accident flight. While the flight was en route, several PIREPs were issued for the area of the accident site, which also indicated the potential of LLWS near the destination airport; however, the controller did not provide this information to the pilot, nor did he solicit PIREP information from the pilot. Based on published Federal Aviation Administration guidance for controllers and the widespread adverse weather conditions in the vicinity of the accident site, the controller should have both solicited PIREP information from the pilot and disseminated information from previous PIREPs to him; this would have provided the pilot with more complete information about the conditions to expect during the approach and landing at the destination.

The pilot was forced to attempt an emergency landing in a wasteland for unknown reason. There were no casualties and the aircraft was damaged beyond repair.

The private pilot, who had recently purchased the airplane, and the flight instructor were conducting an instructional flight in the multi-engine airplane to meet insurance requirements. Radar data for the accident flight, which occurred on the second day of 2 days of training, showed the airplane maneuvering between 1,000 ft and 1,200 ft above ground level (agl) just before the accident. The witness descriptions of the accident were consistent with the airplane transitioning from slow flight into a stall that developed into a spin from which the pilots were unable to recover before the airplane impacted terrain. Examination of the wreckage did not reveal evidence of any preexisting mechanical malfunctions or anomalies that would have precluded normal operation of the airplane. After the first day of training, the pilot told friends and fellow pilots that the instructor provided non-standard training that included stall practice that required emergency recoveries at low airspeed and low altitude. The instructor used techniques that were not in keeping with established flight training standards and were not what would be expected from an individual with his extensive background in general aviation flight instruction. Most critically, the instructor used two techniques that introduced unnecessary risk: increasing power before reducing the angle of attack during a stall recovery and introducing asymmetric power while recovering from a stall in a multi-engine airplane; both techniques are dangerous errors because they can lead to an airplane entering a spin. At one point during the first day of training, the airplane entered a full stall and spun before control was regained at very low altitude. The procedures performed contradicted standard practice and Federal Aviation Administration guidance; yet, despite the pilot's experience in multi-engine airplanes and in the accident airplane make and model, he chose to continue the second day of training with the instructor instead of seeking a replacement to complete the insurance check out. The spin encountered on the accident flight likely resulted from the stall recovery errors advocated by the instructor and practiced on the prior day's flight. Unlike the previous flight, the accident flight did not have sufficient altitude for recovery because of the low altitude it was operating at, which was below the safe altitude required for stall training (one which allows recovery no lower than 3,000 ft agl).

The pilot stated that the engine start and airplane power-up were normal for the air medical flight with two medical crewmembers. The engine ice vanes were lowered (as required for ground operations) and then were subsequently raised before takeoff. Takeoff and climbout were routine, and the pilot leveled off the airplane at the assigned cruise altitude. The air traffic controller informed the pilot of heavy showers near the destination airport, and the pilot "put the ice vanes down." The pilot indicated that, shortly afterward, the airplane experienced two "quick" electrical power fluctuations in which "everything went away and then came back," and "[s]econds later the entire [electrical] system failed." Due to the associated loss of navigation capability while operating in instrument meteorological conditions (IMC), the pilot set a general course for better weather conditions based on information from his preflight weather briefing. While the pilot attempted to find a suitable hole in the clouds to descend through under visual conditions, the left engine lost power. The pilot ultimately located a field through the cloud cover and executed a single-engine off-airport landing, which resulted in substantial damage to the right engine mount and firewall. A postaccident examination of the airplane and systems did not reveal any anomalies consistent with an in-flight electrical system malfunction. The three-position ignition and engine start/starter-only switches were in the ON position, and the engine anti-ice switches were in the ON position. When the airplane battery was initially checked during the examination, the voltmeter indicated 10.7 volts (normal voltage is 12 volts); the battery was charged and appeared to function normally thereafter. The loss of electrical power was likely initiated by the pilot inadvertently selecting the engine start switches instead of the engine anti-ice (ice vane) switches. This resulted in the starter/generators changing to starter operation and taking the generator function offline. Airplane electrical power was then being supplied solely by the battery, which caused it to deplete and led to a subsequent loss of electrical power to the airplane. A postaccident examination revealed that neither wing fuel tank contained any visible fuel. The left nacelle fuel tank did not contain any visible fuel, and the right nacelle fuel tank appeared to contain about 1 quart of fuel. The lack of fuel onboard at the time of the accident is consistent with a loss of engine power due to fuel exhaustion. This was a result of the extended flight time as the pilot attempted to exit instrument conditions after the loss of electrical power to locate a suitable airport. Further, the operator reported that 253 gallons (1,720 lbs) of fuel were on board at takeoff, and the accident flight duration was 3.65 hours. At maximum range power, the expected fuel consumption was about 406 lbs/hour, resulting in an endurance of about 4.2 hours. Thus, the pilot did not have the adequate fuel reserves required for flying in IMC. Both the pilot and medical crewmembers described a lack of communication and coordination among crewmembers as the emergency transpired. This resulted in multiple course adjustments that hindered the pilot's ability to locate visual meteorological conditions before the left engine fuel supply was exhausted.