Airport (less than 10 km from airport)

The single engine aircraft departed New Delhi at 0842LT on an ambulance flight to Bangkok with two pilots and three doctors on board. A refueling stop was completed at Calcutta Airport. At 1903LT, en route to Bangkok-Don Mueang Airport, the crew contacted ATC and requested permission to divert to Kamphaeng Saen Airport due to an emergency. The permission was granted and the crew initiated the descent when the aircraft disappeared from radar screens at 1916LT. The burned wreckage was found an hour and 30 minutes later, at 2048LT, in a wooded area located few km from runway 22L threshold. All five occupants were injured while the aircraft was destroyed. Few hours later, the copilot died from his injuries.

The 69-year-old commercial pilot was making a personal cross-country flight in the newly purchased airplane. When the airplane was on final approach to the destination airport in night visual meteorological conditions, airport surveillance video showed it pitch up and roll to the right. The airplane then descended in a nose-down attitude to impact in a ravine on the right side of the runway. During the descent over the ravine the right wing came in contact with a powerline that briefly cut power to the airport. Postaccident examination of the airframe, engines, and their components revealed no evidence of mechanical anomalies or malfunctions that would have precluded normal operation. The pilot's toxicology findings identified five different impairing medications: clonazepam, temazepam, hydrocodone, nortriptyline, and diphenhydramine. Although the results were from cavity blood and may not accurately reflect antemortem levels, the hydrocodone, temazepam, and diphenhydramine levels were high enough to likely have had some psychoactive effects. While the exact effects of these drugs in combination are not known, it is likely that the pilot was impaired to some degree by his use of this combination of medications, which likely contributed to his failure to maintain control of the airplane.

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. Even 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.

While overflying the Yucatán Province, en route from Monterrey to Cancún, the pilot informed ATC that he was low of fuel and requested the permission to divert to Chichén Itzá Airport for an emergency landing. While approaching the airfield by night, the single engine aircraft descended into trees and crashed few km from the airport. The airplane was destroyed and there was no fire. All five occupants were injured.

Following an uneventful flight, the aircraft belly landed at Unalaska-Tom Madsen Airport runway 13/31. The airplane slid for few dozen metres before coming to rest and was damaged beyond repair. All three occupants evacuated safely.

The aircraft was flying from St Thomas in the US Virgin Islands to Virgin Gorda (VIJ) in the British Virgin Islands. There were eight passengers on board, together with the pilot. It was the pilot’s eleventh flight of the day, and his fourth flight to Virgin Gorda. All these flights were short, with the longest flight being about 40 minutes duration and the shortest just a few minutes. The flight from St Thomas to Virgin Gorda took 35 minutes. The weather in Virgin Gorda was excellent with a light easterly wind and little cloud. The pilot commenced his approach to Virgin Gorda using his usual turning and configuration points. The aircraft touched down normally on runway 03 and the pilot retracted the flaps before applying the brakes. The brakes responded, although the pilot commented that the right brake did not seem to respond as positively as he expected. The pilot reapplied the brakes but the left brake pedal “flopped to the floor”. Judging he had insufficient room to abort the landing, the pilot continued to pump the brakes which he did not consider to be responding. He shut down the engines before the aircraft left the paved surface, struck signage and then a low wall before coming to rest on a bank. The pilot vacated the aircraft through the side window and then opened the main door to allow the passengers to exit the aircraft. None of the occupants was injured. The aircraft was extensively damaged.

The airplane departed Brasilía-Presidente Juscelino Kubitschek Airport in the evening on a charter flight to São Paulo-Congonhas, carrying two pilots and one passenger, the Senator Aécio Neves da Cunha. During the takeoff roll, a tire on one of the main landing gear failed. The crew continued the flight, informed ATC about his situation and preferred to divert to São Paulo-Guarulhos Airport that offered longer runway for an emergency landing. After touchdown by night, the aircraft deviated to the right then veered off runway. The left main gear collapsed and the aircraft came to rest in a grassy area. All three occupants evacuated safely and the aircraft was damaged beyond repair.

Shortly after takeoff from Thebephatshwa AFB, en route to Gaborone, the twin engine aircraft went out of control and crashed 4 km from the airport. All three crew members were killed.

The airline transport pilot reported that, before landing following an uneventful flight, he extended the wing flaps to the approach position and extended the landing gear; the gear indicator lights showed "3 green." After touchdown, he heard noises, and the airplane started to sink. After the airplane came to a stop on the right side of the runway, he noticed that the landing gear handle was up. The pilot stated to the copilot, "How did the gear handle get up?" then placed the handle to the down position and the flight crew exited the airplane. The copilot reported that he was acting as an observer during the flight and that he also saw three green landing gear down-and-locked indicator lights before landing. The airframe sustained substantial damage from contact with the runway. All three landing gear were found in a partially-extended position. Skid marks from all three tires were observed on the runway leading up to the main wreckage. Both propeller assemblies were damaged due to contact with the runway. The pressure vessel was compromised from contact with a propeller blade. The nose landing gear actuator was forced up, into the nose gear well and penetrated the upper nose skin. Examination of the landing gear components did not reveal evidence of a preexisting mechanical malfunction or malfunction. The skid marks leading to the wreckage and the partially-extended gear were inconsistent with the pilot's account that the gear handle was up after the airplane came to rest and was then lowered. The gear handle consisted of an electrical switch that required it to be pulled out of a detent before placing it up or down. There was no mechanical linkage between the gear handle and the landing gear, as the gear were driven by an electric motor. It is likely that the pilot realized that the gear were not extended just before touchdown and then tried to lower the gear, resulting in a touchdown with the gear only partially extended. The pilot reported that he had experienced several interruptions to his sleep the night before the accident. He also reported that he flew 7 legs on the day of the accident for a total of 5.2 hours, only eating a banana for breakfast during this time period. It is likely that the pilot's fatigue contributed to his failure to ensure that the landing gear were down and locked before landing.

The pilot and the passenger departed on a cross-country, personal flight in the airplane that the operator had purchased the day before the accident. Shortly after takeoff from runway 11L, after reaching an altitude of about 100 to 150 ft above the runway in a nose-high pitch attitude, the airplane rolled left to an inverted position as its nose dropped, and it descended to terrain impact on airport property, consistent with an aerodynamic stall. Post-accident examination of the accident site revealed propeller strike marks separated at distances consistent with both propellers rotating at the speed required for takeoff and in a normal blade angle range of operation at impact. Both engines exhibited rotational scoring signatures that indicated the engines were producing symmetrical power and were most likely operating in the mid-to upper-power range at impact. The engines did not display any pre-impact anomalies or distress that would have precluded normal engine operation before impact. No evidence was found of any preexisting mechanical anomalies that would have precluded normal operation of the airplane. Toxicology testing revealed the pilot's use of multiple psychoactive substances including marijuana, venlafaxine, amphetamine, pseudoephedrine, clonazepam, and pheniramine. The wide variety of psychoactive effects of these medications precludes predicting the specific effects of their use in combination. However, it is likely that the pilot was impaired by the effects of the combination of psychoactive substances he was using and that those effects contributed to his loss of control. The investigation was unable to obtain medical records regarding any underlying neuropsychiatric disease(s); therefore, whether these may have contributed to the accident circumstances could not be determined.