Flight

While en route to the destination airport, the pilot was issued a clearance to descend. As the airplane descended to the assigned altitude, radar plots depicted the airplane entering a right turn, climbing rapidly, and then descending rapidly in a spiral-like pattern. The airplane wreckage was found the following day in mountainous terrain. Several tall trees surrounded the perimeter of the wreckage. Many of the trees showed scuff marks down the trunks consistent with the airplane impacting the terrain in a near-vertical descent. All airplane components were accounted for at the accident site. A postaccident examination of the airplane showed no preimpact failures of the airframe or the engine. A weather analysis revealed that the airplane was descending in the immediate vicinity of a stationary front. The weather conditions in the area were conducive to the production of moderate to severe turbulence, mountain wave activity with updraft/downdrafts in excess of 750 feet per minute, and moderate icing. The radar data confirmed that the airplane began its rapid descent shortly after entering cumuliform clouds. The radar information along with the wreckage at the accident site was consistent with the pilot losing control while trying to maneuver the airplane in an area of turbulent weather.

The twin engine aircraft departed Porlamar on a private flight to Charallave, carrying five passengers and one pilot, all from the same family. It is believed that the pilot changed his destination en route and elected to continue to the Cojedes Province. Due to fuel exhaustion, both engines lost power then failed, forcing the pilot to attempt an emergency landing. The aircraft crashed in a wooded area located near Macapo. A young girl aged 10 was seriously injured while five other occupants were killed.

About 20 minutes after departing on a cross-country flight, the pilot acknowledged the air traffic controller’s clearance to climb to 17,000 feet mean sea level (msl). Radar data indicated that the airplane reached a maximum altitude of 16,800 feet msl. The airplane then entered a right descending turn followed by a left descending turn. While in the left turn, the pilot informed the controller, “I lost my autopilot; I’m in an unusual attitude.” The pilot stated this same information two more times in response to transmissions by the controller. The pilot’s last transmission was that he was busy trying to recover the airplane. Witnesses heard the airplane flying overhead for several minutes, but they could not see it due to the low ceiling. A postaccident examination of the airplane did not reveal any pre accident mechanical malfunctions or failures with the engine that would have precluded normal operation. Examination of the autopilot system revealed a loose screw inside the pitch servo housing. The screw was one of two that secured the high wattage resistor to the solenoid housing. Observed corrosion within the screw threads was consistent with the threads not being engaged in a nut or other internally threaded feature. No mechanical damage or arcing was visible on the screw. The operational impact of the loose screw is unknown. The pilot’s instrument flying proficiency could not be determined. According to log records, the pilot last flew 4.5 months before the accident. The airplane was in instrument meteorological conditions when the pilot stated that he was trying to recover from the unusual attitude. The pilot did not follow prescribed procedures for an autopilot malfunction. Weather data indicates that the airplane most likely encountered turbulence and icing conditions during the flight; however, the airplane was equipped with an ice protection system. Although ethanol was found during the toxicology tests, the levels varied greatly among the tissue/fluid samples. The investigation was unable to determine if the presence of ethanol was from ingestion or from postmortem production or contamination. The detected level of diphenhydramine, an over-the-counter sedating antihistamine used to treat allergies, was above therapeutic levels and likely contributed to the pilot’s inability to recover from the unusual attitude.

The crew was returning to his base at Tver-Migalovo after he delivered a MiG-31 to the Voronezh Military Aviation Engineering University. While in cruising flight, the four engine aircraft entered an uncontrolled descent and crashed in a snow covered prairie located near Krasny Oktyabr. The aircraft was totally destroyed and all 12 occupants were killed.

The twin engine aircraft was en route from Yellowknife, NT to Fort St. John, BC. The pilot noticed fumes and smoke coming from behind the rear cabin wall. The cabin was depressurized and the door opened to clear the smoke. A forced landing was conducted onto the frozen surface of Falaise Lake, NT. The pilot immediately egressed, however, the aircraft was soon engulfed in flames and was completely consumed. The pilot was not injured and was flown out by helicopter.

The pilot departed the airport mid-morning to fly to his home airport, 63 miles to the northwest. Weather conditions at the departureb airport were visual flight rules (VFR), the weather at the destination airport was not reported, and the weather conditions en-route were marginal VFR. The global positioning system (GPS) track for the flight indicated that the airplane departed from the airport and headed west along a highway corridor flying approximately 1,000 feet above ground level (agl) through a mountain pass. For the majority of the flight, the airplane maintained altitudes between 900 feet and 1,200 feet agl. Twenty-nine minutes after takeoff, the airplane’s GPS track turned southwest away from an area of concentrated precipitation and directly towards an isolated mountain peak that rose approximately 1,000 feet above the surrounding terrain. The pilot contacted the local air traffic control facility, reported his position and requested traffic advisories through the local airspace to his destination airport. About 6 minutes later, the pilot stated that he was having difficulty maintaining VFR and asked for an instrument flight rules (IFR)clearance. At the same time, the GPS track showed that the airplane came within 50 feet of the mountainous terrain. No further transmissions from the pilot were received. The final GPS position was recorded 1 minute later, at 500 feet agl and approximately half a mile from the crash site. The terrain rapidly ascended in this area and intersected the airplane's flight path over the remaining 1/2 mile. An airport located about 4 miles from the accident site and in an area of flat terrain 1,000 feet below the isolated mountain top, recorded weather at the time of the accident as few clouds at 900 feet agl, overcast clouds at 1,500 feet agl, and a variable ceiling between 1,200 and 1,800 feet agl, in drizzle. Weather radar images at the time of the accident depicted precipitation at the elevation and location of the accident site, indicating probable mountain obscuration.

The twin engine aircraft departed Lamidanda Airport at 1508LT on a flight to Kathmandu. Shortly after departure, the crew was cleared to climb to 10,500 feet but ATC ask them to maintain 8,500 feet due to traffic. The captain disagreed with this ATC instruction and continued to climb. The copilot asked the captain to accept the ATC proposal so finally, the captain cleared the copilot (who was the pilot in command) to descend to 8,500 feet despite the fact it was risky due to the mountainous terrain. Few minutes later, the aircraft entered clouds when the right wing impacted ground. The aircraft crashed in a rocky area located on the Palunge Hill, near Okhaldhunga. The wreckage was found the following morning. The aircraft was destroyed by impact forces and all 22 occupants were killed. IMC conditions prevailed at the time of the accident due to low visibility (cloudy conditions).

The twin engine aircraft departed Tangier on a flight to Ouarzazate, carrying three Police Officers and two pilots on behalf of the Royal Moroccan Police (Gendarmerie Royale Marocaine). While cruising by night between Demnate and Ouarzazate, the aircraft struck a mountain slope and crashed. The wreckage was found two days later in an isolated area. The aircraft was totally destroyed and all five occupants were killed. For unknown reasons, the crew was flying at an insufficient altitude.

About 2 hours into a cross-country flight over water, the pilot heard a noticeable change in engine noise and observed erratic engine torque readings. Moments later the airplane experienced a complete loss of engine power. After declaring an emergency, the pilot attempted to diagnose the problem and restart the engine to no avail. The airplane ditched 175 miles from land, in water over 5,000 feet deep. The airplane was not recovered and the reason for the loss of engine power could not be determined.

En route from Basco to Tuguegarao, the crew encountered technical problems and elected to divert to the nearest airport for an emergency landing. The twin engine aircraft stalled and crashed in a river. All 13 occupants, among them two children, evacuated safely. The aircraft damaged beyond repair.