Flight

The pilot, sole on board, departed Ozeryany on a private flight to Gardychyvka. En route, weather conditions deteriorated with low clouds and fog. The pilot decided to continue and reduced his altitude to maintain a visual contact with the ground when the aircraft struck the ground and crashed in a snow covered field. The pilot was seriously injured and the aircraft was destroyed.

The twin engine aircraft departed Maringá Airport at 1837LT on a flight to São Paulo, carrying four passengers and one pilot. 35 minutes into the flight, about five minutes after he reached its assigned altitude of 21,000 feet, the aircraft stalled and entered an uncontrolled descent. The pilot was unable to regain control, the aircraft partially disintegrated in the air and eventually crashed in a flat attitude in a field. The aircraft was destroyed and all five occupants were killed.

The aircraft departed South Pole Station, Antarctica, at 0523 Coordinated Universal Time on 23 January 2013 for a visual flight rules repositioning flight to Terra Nova Bay, Antarctica, with a crew of 3 on board. The aircraft failed to make its last radio check-in scheduled at 0827, and the flight was considered overdue. An emergency locator transmitter signal was detected in the vicinity of Mount Elizabeth, Antarctica, and a search and rescue effort was initiated. Extreme weather conditions hampered the search and rescue operation, preventing the search and rescue team from accessing the site for 2 days. Once on site, it was determined that the aircraft had impacted terrain and crew members of C-GKBC had not survived. Adverse weather, high altitude and the condition of the aircraft prevented the recovery of the crew and comprehensive examination of the aircraft. There were no indications of fire on the limited portions of the aircraft that were visible. The accident occurred during daylight hours.

The twin engine aircraft departed Los Roques Island Airport Runway 07 at 1132LT on a charter flight to Caracas, carrying four passengers and two pilots. During initial climb, the crew was cleared to climb to 6,500 feet. Seven minutes later, the crew informed ATC he was climbing to 5,000 feet and reported his position some 10 NM from Gran Roque VOR. While cruising at 5,400 feet at a speed of 120 knots, the aircraft entered an uncontrolled descent and crashed in the sea. SAR operations did not find any trace of the aircraft nor the six occupants and all operations were abandoned after one week. The Italian couturier Vittorio Missoni was among the passenger. In June 2013, some debris were localized at a depth of 75 meters and five bodies were found on 17OCT2013. Eventually, the wreckage was recovered on 25NOV2013.

The aircraft was completing a flight on behalf of the Kazakh Border Guard Corp. While approaching Shymkent in low visibility due to the night and heavy snow falls, the aircraft hit a mountain slope located 21 km from the airport and was destroyed by impact forces. All 27 occupants were killed, among them Tourganbek Stambekov, Chief of the Kazakhtan Border Guards. It appears that the automatic pilot system failed shortly after take off from Astana and the captain decided to continue the flight. Two minutes and 40 seconds later, the radio altimeter failed as well and the crew continued the flight, referring to the barometric altimeter. But these suffered a momentary failure 19 minutes later and several differences were observed with the altitude parameters. During the descent to Shymkent in poor weather conditions, the captain failed to set the correct pressure in the barometric altimeters so the setting he was taking for reference was wrong. At the time of the accident, the aircraft was 385 meters too low and as a result, the Board concluded that the accident was the consequence of a controlled flight into terrain (CFIT).

The pilot began flying the twin piston-engine airplane model for the cargo airline about 11 months before the accident. Although he had since upgraded to one of the airline’s twin turboprop airplane models, due to the airline’s logistical needs, the pilot was transferred back to the piston-engine model about 1 week before the accident. The flight originated at one of the airline’s outlying destination airports and was planned to stop at an interim destination to the southwest before continuing to the airline’s base as the final destination. The late afternoon departure meant that the flight would arrive at the interim destination about 10 minutes after sunset. That interim destination was situated in a sparsely populated geographic bowl just south of terrain that was significantly higher, and the ceilings there included multiple broken and overcast cloud layers near, or lower than, the surrounding terrain. Although not required by Federal Aviation Administration (FAA) regulations, the airline employed dedicated personnel who performed partial dispatch-like activities, such as providing relevant flight information, including weather, to the pilots. Before takeoff on the accident flight, the pilot conferred briefly with the dispatch personnel by telephone, and, with little discussion, they agreed that the flight would proceed under visual flight rules to the interim destination. Information available at the time indicated that the cloud cover almost certainly precluded access to the airport without an instrument approach; however, the airplane was not equipped to conduct the only available instrument approach procedure for that airport. Additionally, the pilot did not have in-flight access to any GPS or terrain mapping/database information to readily assist him in either locating the airport or remaining safely clear of the local terrain. Although the airplane was not being actively tracked or assisted by air traffic control (ATC) early in the flight, review of ground tracking radar data showed that the flight initially headed directly toward the interim destination but then began a series of turns, descents, and climbs. The airplane then disappeared from radar as the result of radar coverage floor limitations due to high terrain and radar antenna siting. The airplane reappeared on radar about 24 minutes after it disappeared and about 9 minutes after the FAA-defined beginning of night. Based on the flight track, it is likely that the pilot made a dedicated effort to access the airport, while concurrently remaining clear of the clouds and terrain, strictly by visual means. This task was made considerably more difficult and hazardous by attempting it in dusk conditions, and then darkness, instead of during daylight hours. About 15 minutes after the airplane reappeared on radar, when it was at an altitude of about 13,500 ft, the pilot contacted ATC and requested and was granted an instrument flight rules clearance to his final destination. About 3 minutes later, the controller cleared the flight to descend to 10,000 ft, and the airplane leveled off at that altitude about 6 minutes later. However, upon reaching 10,000 ft, the pilot requested a lower altitude to escape “heavy” upand down-drafts, but the controller was unable to comply because the ATC minimum vectoring altitude was 9,700 ft in that region. About 1 minute later, radar contact was lost. Shortly thereafter, the airplane impacted terrain in a steep nose-down attitude in a near-vertical trajectory. Although examination of the wreckage did not reveal any preimpact mechanical deficiencies that would have prevented normal operation and continued flight, the extent of the damage precluded, except on a macro scale, any determination of the preimpact integrity or functionality of any systems, subsystems, or components, including the ice protection systems, autopilot, and nose baggage door. Analysis of the radar data indicated that the airplane was above 10,000 ft for at least 41 minutes (possibly in two discontinuous periods) and above 12,000 ft (in two discontinuous periods) for at least 18 minutes. Although the airplane was reportedly equipped with supplemental oxygen, the investigation was unable to verify either its presence or its use by the pilot. Lack of supplemental oxygen at those altitudes for those periods could have contributed to a decrease in the pilot’s mental acuity and his ability to safely conduct the light. Analysis of air mass data revealed that mountain-wave activity and up- and downdrafts with vertical velocities of about 1,000 ft per minute (fpm) were present near the accident site and that the largest and most rapid transitions from up- to down-drafts occurred near the accident site, which was also supported by the airplane’s altitude data trace. The analysis also indicated that the last radar target from the airplane was located in a downdraft with a velocity of between 600 and 1,000 fpm. Other meteorological analysis indicated that the airplane encountered icing conditions, likely in the form of supercooled large droplets (SLD), several minutes before the accident. Aside from pilot reports from aircraft actually encountering SLD, no tools currently exist to detect airborne SLD. Further, the tools and processes to reliably forecast SLD do not exist. SLD is often associated with rapid ice accumulation, especially on portions of the airplane that are not served by ice protection systems. Airframe icing, whether due to accumulation rates or locations that exceed the airplane’s deicing system capabilities, mechanical failure, or the pilot’s failure to properly use the system, can impose significant adverse effects on airplane controllability and its ability to remain airborne. Because of the pilot’s recent transition from the Beechcraft BE-99, in which the pitot heat was always operating during flight, he may have forgotten that the accident airplane’s pitot heat procedures were different and that the pitot heat had to be manually activated when the airplane encountered the icing conditions. If the pitot heat is not operating in icing conditions, the airspeed information becomes unreliable and likely erroneous. Erroneous airspeed indications, particularly in night instrument meteorological conditions when the pilot has no outside references, could result in a loss of control. The investigation was unable to determine whether the pitot heat was operating during the final portion of the flight. The investigation was unable to determine whether the pilot used the autopilot during the last portion of the flight. If he was using the autopilot, it is possible that, at some point, he was forced to revert to flying the airplane manually due to the unit’s inability and to a corresponding Pilot’s Operating Handbook prohibition against using it to maintain altitude in the strong up- and downdrafts, which would increase the pilot’s workload. Another possibility is that the autopilot was unable to maintain altitude, and, instead of disconnecting it, the pilot overpowered it via the control wheel. If that occurred and the pilot overrode the autopilot for more than 3 seconds, the pitch autotrim system would have activated in the direction opposite the pilot’s input, and, when the pilot released the control wheel, the airplane could have been significantly out of trim, which could result in uncommanded pitch, altitude, and speed excursions and possible loss of control. Whether the pilot was hand-flying the airplane or was using the autopilot, the encounter with the strong up- and downdrafts and consequent altitude loss likely prompted the pilot to input corrective actions to regain the lost altitude, specifically increasing pitch and possibly power. Such corrections typically result in airspeed losses; those losses can sometimes be significant as a function of downdraft strength and the airplane’s climb capability. If that capability is compromised by the added weight, drag, and other adverse aerodynamic effects of ice, aerodynamic stall and a loss of control could result. Radar tracking data and ATC communications revealed that another, similar-model airplane flew a very similar track about 6 minutes behind the accident airplane, except that that other airplane was at 12,000 ft not 10,000 ft. The 10,000-ft ATC-mandated altitude placed the accident airplane closer to the underlying high terrain and into the clouds with the icing conditions and the strong vertical air movements. In contrast, the pilot of the second airplane reported that he was in and out of the cloud tops and did not report any weather-induced difficulties. The accident pilot did not have any efficient in-flight means for accurately determining the airborne meteorological conditions ahead, and the ATC controller did not advise him of any adverse conditions. Therefore, the pilot did not have any objective or immediate reason to refuse the ATC-assigned altitude of 10,000 ft. Ideally, based on both the AIRMET and the ambient temperatures, the pilot should have been aware of the likelihood of icing once he descended into clouds. That, particularly combined with his previously expressed lack of confidence in the airplane’s capability in icing conditions, could have prompted him to request either an interim stepdown altitude of 12,000 ft or an outright delay in a direct descent to 10,000 ft, but, for undetermined reasons, the pilot did not make any such request of ATC. Based on the available evidence, if the ATC controller had not descended the airplane to 10,000 ft when he did, either by delaying or by assigning an interim altitude of 12,000 ft, it is likely that the airplane would not have encountered the icing conditions and the strong up- and downdrafts. In addition, if the presence of SLD and/or strong up- and downdrafts had been known or explicitly forecast and then communicated to the pilot either via his weather briefing, his onboard equipment, or by ATC, it is likely that the pilot would have opted to avoid those phenomena to the maximum extent possible. The flight’s encounter with airframe icing and strong up-and downdrafts placed the pilot and airplane in an environment that either exacerbated or directly caused a situation that resulted in the loss of airplane control.

The crew was performing a cargo flight from Lima to Las Malvinas (Sabeti), and departed Lima-Jorge Chávez Airport at 1009LT for a 78-minutes flight. 32 minutes into the flight, while overflying the Andes mountains at FL195, the crew lost control of the airplane that crashed in a mountainous area located near Tomas. The wreckage was found the following day and all four occupants were killed while.

The private pilot and passenger departed on the 875-nautical-mile cross-country flight and leveled off at a cruise altitude of 24,000 feet mean seal level, which, based on the radar data, was accomplished with the use of the autopilot. About 1 hour 40 minutes after departure, the pilot contacted air traffic control personnel to request that he would “like to leave frequency for a couple of minutes.” No further radio transmissions were made. About 20 seconds after the last transmission, the airplane banked to the right, continued in a spiral while rapidly descending, and subsequently broke apart. At no time during the flight did the pilot indicate that he was experiencing difficulty or request assistance. Just prior to departing from the flight path, the pilot made an entry of the engine parameters in a flight log, which appeared to be consistent with his other entries indicating the airplane was not experiencing any difficulties. Portions of the wings, along with the horizontal stabilizers and elevators, separated during the breakup sequence. Analysis of the fracture surfaces, along with the debris field distribution and radar data, revealed that the rapid descent resulted in an exceedance of the design stress limits of the airplane and led to an in-flight structural failure. The airplane sustained extensive damage after ground impact, and examination of the engine components and surviving primary airframe components did not reveal any mechanical malfunctions or failures that would have precluded normal operation. The airplane was flying on a flight path that the pilot was familiar with over largely unpopulated hilly terrain at the time of the upset. The clouds were well below his cruising altitude, giving the pilot reliable external visual cues should the airplane have experienced a failure of either the flight instruments or autopilot. Further, no turbulence was reported in the area. The airplane was equipped with a supplemental oxygen system, which the pilot likely had his mask plugged into and available in the unstowed position behind his seat; the passenger’s mask was stowed under her seat. The airplane’s autopilot could be disengaged by the pilot by depressing the appropriate mode switch, pushing the autopilot disengage switch on the control wheel, or turning off the autopilot switch on the control head. All autopilot servos were also equipped with a clutch mechanism that allowed the servo to be manually overridden by the pilot at any time. It is likely that the reason the pilot requested to “leave the frequency” was to leave his seat and attend to something in the airplane. While leaving his seat, it is plausible he inadvertently disconnected the autopilot and was unable to recover by the time he realized the deviation had occurred.

During the cross-country instrument flight rules flight, the pilot was in contact with air traffic control personnel. The controller cleared the airplane to flight level 210 and gave the pilot permission to deviate east of the airplane's route to avoid weather and traffic. A review of radar data showed the airplane heading southward away from the departure airport and climbing to an altitude of about 14,800 feet mean sea level (msl). Shortly thereafter, the airplane turned north, and the controller queried the pilot about the turn; however, he did not respond. The airplane wreckage was located on ranch land with sections of the airplane's outer wing, engines, elevators, and vertical and horizontal stabilizers separated from the fuselage and scattered in several directions, which is consistent with an in-flight breakup before impact with terrain. A review of the weather information for the airplane's route of flight showed widely scattered thunderstorms and a southerly surface wind of 30 knots with gusts to 40 knots. An AIRMET active at the time advised of moderate turbulence below flight level 180. Three pilot reports made within 50 miles of the accident site indicated moderate turbulence and mountain wave activity. An assessment of the humidity and freezing level noted the potential for clear, light-mixed, or rime icing between 10,700 and 17,300 feet msl. Postaccident airplane examination did not reveal any mechanical malfunctions or anomalies with the airframe and engines that would have precluded normal operation. It's likely the airplane encountered heavy to extreme turbulence and icing conditions during the flight, which led to the pilot’s loss of control of the airplane and its subsequent in-flight breakup.

The aircraft crashed in unknown circumstances in Waitaanga while completing a spraying mission between Taumatunui and Mount Messenger. The aircraft was destroyed and the pilot, sole on board, was seriously injured.