Mountains

The pilot, sole on board, departed Siegerland Airport at 1100LT on a ferry flight to Arezzo, Tuscany. En route, while overflying Switzerland, he encountered marginal weather conditions. While cruising in IMC conditions, the single engine airplane impacted the slope of a rocky and snow covered face located west of Mt Grüehorn, in the south part of the canton of St Gallen. The wreckage was found later in the afternoon at an altitude of 1,700 metres. The aircraft was destroyed and the pilot was killed.

The airplane departed Kunming-Wujiaba Airport at 1315LT on a schedule service (flight MU5735) to Guangzhou, carrying 123 passengers and a crew of nine. At 1420LT, while cruising at an altitude of 29,100 feet, the aircraft entered an uncontrolled descent until 7,400 feet then climbed to 8,600 feet. It finally entered a steep descent and crashed almost two minutes later in a vertical attitude on hilly and wooded terrain located some 20 km southwest of Wuzhou. The airplane disintegrated on impact and all 132 occupants were killed. Two days after the accident, the CVR was found while the DFDR was found on March 27.

The pilot was conducting a solo night cross-country flight in low visibility through mountainous terrain. The pilot was then cleared by an air traffic controller to conduct a RNAV (GPS)-E instrument approach into the destination airport. After passing the final approach fix and before the missed approach point, the pilot, for an unknown reason, executed a left turn, consistent with the missed approach procedure. During the turn toward the holding waypoint, the airplane did not climb. Shortly thereafter, the airplane impacted steep rising terrain The local weather at the time of the accident indicated a cloud ceiling of 1,200 ft above ground level and 1 statute mile visibility, which was below the weather minimums for the approach. Data retrieved from the onboard avionics revealed that although the pilot flew the published route in accordance with the instrument approach procedure, the minimum required altitudes were not adhered to. A review of the ForeFlight weather briefing data indicated that a route weather briefing had been generated by the pilot with the filing of the instrument flight rules (IFR) flight plan. While no weather imagery was reviewed during the period, the pilot had checked METARs for the destination and another nearby airport before departure and viewed the RNAV (GPS)-E approach procedure at the destination airport. A review of the data that was presented to the pilot indicated that visual flight rules conditions prevailed at the destination with light snow in the vicinity at the time it was generated. Based on the preflight weather briefing the pilot obtained, he was likely unaware of the IFR conditions and below minimum weather conditions at the destination until he descended into the area and obtained the current local weather during the flight. It is probable that, based upon the weather and flight track information, as the pilot was on the instrument approach, he became aware of the below minimum weather conditions and elected to initiate the missed approach, as evident by the turn away from the airport similar to the missed approach procedure and the flaps and landing gear being in transition. This investigation was unable to determine why the missed approach procedure was prematurely initiated and why the airplane failed to climb. Additionally, there were no preimpact mechanical malfunctions or anomalies found during a postaccident examination that would have precluded normal operation.

The airplane was engaged in a calibration mission at Khabarovsk-Novy Airport, carrying six crew members. The goal of the flight was to caliber the ILS system of runway 05R. In the afternoon, the airplane departed Khabarovsk-Novy Airport and completed several circuits over the aerodrome and the area. The crew was instructed to climb away from the airport to an altitude of 600 metres and to turn to follow the reverse approach course. However, the minimum published altitude for that sector up to a distance of 46 km was fixed to 1,200 metres. The crew continued at an altitude of 600 metres with a heading of 220° for few minutes. While initiating a slight climb and while flying at an altitude of 742 metres in poor visibility due to marginal weather conditions, the airplane impacted trees and crashed on the wooded slope of Mt Khrebtovaya (793 metres high) located in the Bolchoï Khekhtsir Mountain Range, some 40 km southwest of Khabarovsk Airport. The aircraft was totally destroyed by impact forces and all six occupants were killed.

On 15 September 2021, a DHC-6-300 (Twin Otter) aircraft registered PK-OTW was being operated for an unscheduled cargo flight from Douw Aturure Airport (WABI), Nabire, Papua to Bilorai Airport (WAYB), Intan Jaya, Papua. The aircraft was operated by two pilots accompanied by one engineer on board. The filed flight plan for the flight indicated that the aircraft would be operated under Visual Flight Rule (VFR) with fuel endurance of 2 hours 30 minutes. The estimate time departure for the flight was at 0640 LT. At 0610 LT, the pilot received weather observation report from the Bilorai aeronautical communication officer (ACO) that the visibility was 5 up to 7 kilometers, several clouds over the airport and all final areas were clear. About 7 minutes later, the ACO updated the observation report which indicated that the visibility changed to 7 up to 8 kilometers (km). After the cargo loading process and the flight preparation had completed, the aircraft taxied to Runway 16. At 0644 LT, the aircraft departed and climbed to the cruising altitude of 9,500 feet. Prior to the departure, there was no record or report of aircraft system malfunction. The Pilot in Command (PIC) acted as Pilot Monitoring (PM) while the Second in Command (SIC) acted as Pilot Flying (PF). At 0658 LT, the PK-OTW pilot reported to the Nabire air traffic control that the aircraft was at 25 Nm with altitude of 9,500 feet. At 0702 LT, the SIC asked the PIC to have the aircraft control as PF. During flight, the PK-OTW pilots monitored weather information provided by the pilots of two other aircraft that flew ahead of the PK-OTW to Bilorai. Both pilots monitored that the first aircraft (Cessna 208B EX) landed using Runway 27 while the second aircraft (Cessna 208B) would use Runway 09. At 0715 LT, the PIC advised the SIC to use the Runway 27 for landing. At 0719 LT, the SIC made initial contact with the ACO and advised that the aircraft was approaching Bilai at altitude of 9,500 feet and the estimate time arrival at Bilorai was 0726 LT. The ACO acknowledged the pilot report and provided current weather observation as follows “…wind westerly 3 until 5 knots, final 09 open with broken fog and final 27 open, visibility 5 until 7 km, blue sky overhead”. The SIC acknowledged the weather information and advised the ACO would report when the aircraft position was on left downwind Runway 27. At 0721 LT, the SIC read the descent checklist included the item of Landing Data/Approach Briefing and was replied by completed. The Cockpit Voice Recorder (CVR) did not record any pilot’s discussion regarding to the airport minimum safe altitude since the beginning of the recording. At 0723 LT, a pilot of DHC-6-400 aircraft registered PK-OTJ, asked the PK-OTW pilot of the weather condition in Bilorai. The PK-OTJ flew behind the PK-OTW with from Nabire to Bilorai. The SIC then responded that the PK-OTW was on descend and would fly through clouds about 5 Nm to Bilorai. Thereafter, the ACO provided traffic information to PK-OTW pilot that there was an aircraft (Cessna 208B aircraft) on final Runway 09. The PIC who acted as PF acknowledged the traffic information and advised to the ACO that the PK-OTW would join left downwind Runway 27 for the landing approach. At 0725 LT, the SIC advised to the ACO that the aircraft was on left downwind Runway 27. The ACO then advised the PK-OTW pilot to report when on final Runway 27. At 07:26:12 LT, a stall warning recorded in the Cockpit Voice Recorder (CVR) then the PIC asked to the SIC to check the aircraft speed. The SIC responded the aircraft speed was 65 knots. At 07:26:16 LT, the PIC asked to the SIC to advise the ACO that they were making a go around. The SIC then advised the ACO that the PK-OTW was making a go around and was responded to report when on final. The CVR did not record pilot’s discussion about the plan maneuver of the go around. At 07:26:45 LT, the PIC informed that they were making a go around to the PK-OTJ pilot. The PK-OTJ pilot responded that the aircraft was approaching Homeyo and would reduce the speed to make enough separation with the PK-OTW. The PIC then advised the PK-OTJ that the PK-OTW would attempt to land using Runway 09. Based on the data transmitted from the flight following system, at 07:27:57 LT, the aircraft was about 3 Nm outbound from Bilorai on direction of 238°. At 07:28:22 LT, the PK-OTJ pilot advised to the ACO that the aircraft was about 6 nm to Bilai and the pilot intended to make holding maneuver over Bilai to make enough separation with the PK-OTW. At 07:28:33 LT, the SIC advised the PIC that the aircraft was at 8,200 feet and was responded that the PIC initiated turning the aircraft. A few second later, the SIC advised to the PIC that the aircraft was turning, and the aircraft was at 3.2 Nm outbound from Bilorai. At 07:28:38 LT, the last data of the flight following system recorded that the aircraft was on direction of 110°. At 07:29:25 LT, the SIC advised the PIC to fly left. Thereafter, the SIC advised the PIC that the aircraft was passing 8,000 feet. At 07:29:35 LTC, the PIC asked to the SIC about the distance to Bilorai and was responded 2.5 Nm. The SIC, reminded the PIC to fly left as the aircraft flew too close to the terrain. At 07:29:49 LT, the CVR recorded the first impact sound and the CVR recording stopped at 07:29:55 LT. At 0730 LT, the ACO asked the PK-OTW pilot intention as the aircraft was not visible from the ACO working position, and the pilot did not respond the ACO. At about the same time, the ACO heard impact sound that was predicted coming from terrain area on west of Bilorai. The ACO then called the PK-OTW pilot several times without response. Several pilots also attempted to contact the PK-OTW with the same result. The PK-OTW was found on a ridge at elevation of 8,100 feet, about 2 Nm on bearing 260° from Bilorai.

Owned and operated by the Russian Navy, the aircraft was dispatched in Turkey in July to help the Turkish government (General Directorate of Forestry) to fight raging forest fires in the southeast part of the country. On board were eight crew members, five Russian and three Turkish. After the aircraft drop water on fire, the crew elected to gain height when the aircraft impacted terrain and crashed on the slope of a mountain, bursting into flames. The aircraft was totally destroyed and all 8 occupants were killed.

The accident flight was the pilot’s second passenger sightseeing flight of the day that overflew remote inland fjords, coastal waterways, and mountainous, tree-covered terrain in the Misty Fjords National Monument. Limited information was available about the airplane’s flight track due to radar limitations, and the flight tracking information from the airplane only provided data in 1-minute intervals. The data indicated that the airplane was on the return leg of the flight and in the final minutes of flight, the pilot was flying on the right side of a valley. The airplane impacted mountainous terrain at 1,750 ft mean sea level (msl), about 250 ft below the summit. Examination of the wreckage revealed no evidence of pre accident failures or malfunctions that would have precluded normal operation. Damage to the propeller indicated that it was rotating and under power at the time of the accident. The orientation and distribution of the wreckage indicated that the airplane impacted a tree in a left-wing-low attitude, likely as the pilot was attempting to maneuver away from terrain. Review of weather information for the day of the accident revealed a conditionally unstable environment below 6,000 ft msl, which led to rain organizing in bands of shower activity. Satellite imagery depicted that one of these bands was moving northeastward across the accident site at the accident time. Federal Aviation Administration (FAA) weather cameras and local weather observations also indicated that lower visibility and mountain obscuration conditions were progressing northward across the accident area with time. Based on photographs recovered from passenger cell phones along with FAA weather camera imagery, the accident flight encountered mountain obscuration conditions, rain shower activity, and reduced visibilities and cloud ceilings, resulting in instrument meteorological conditions (IMC) before the impact with terrain. The pilot reviewed weather conditions before the first flight of the day; however, there was no indication that he obtained updated weather conditions or additional weather information before departing on the accident flight. Based on interviews, the accident pilot landed following the first flight of the day in lowering visibility, ceiling, and precipitation, and departed on the accident flight in precipitation, based on passenger photos. Therefore, the pilot had knowledge of the weather conditions that he could have encountered along the route of flight before departure. The operator had adequate policies and procedures in place for pilots regarding inadvertent encounters with IMC; however, the pilot’s training records indicated that he was signed off for cue-based training that did not occur. Cue-based training is intended to help calibrate pilots’ weather assessment and foster an ability to accurately assess and respond appropriately to cues associated with deteriorating weather. Had the pilot completed the training, it might have helped improve his decision-making skills to either cancel the flight before departure or turn around earlier in the flight. The operator’s lack of safety management protocols resulted in the pilot not receiving the required cue-based training, allowed him to continue operating air tours with minimal remedial training following a previous accident, and allowed the accident airplane to operate without a valid FAA registration. The operator was signatory to a voluntary local air tour operator’s group letter of agreement that was developed to improve the overall safety of flight operations in the area of the Misty Fjords National Monument. Participation was voluntary and not regulated by the FAA, and the investigation noted multiple instances in which the LOA policies were ignored, including on the accident flight. For example, the accident flight did not follow the standard Misty Fjords route outlined in the LOA nor did it comply with the recommended altitudes for flights into and out of the Misty Fjords. FAA inspectors providing oversight for the area reported that, when they addressed operators about disregarding the LOA, the operators would respond that the LOA was voluntary and that they did not need to follow the guidance. The FAA’s reliance on voluntary compliance initiatives in the local air tour industry failed to produce compliance with safety initiatives or to reduce accidents in the Ketchikan region.

On July 10, 2021, about 1254 mountain standard time, a Beech C-90, turbo prop airplane, N3688P, was destroyed when it was involved in an accident near Wikieup, Arizona. The pilot and Air Tactical Group supervisor were fatally injured. The airplane was operated as a public use firefighting aircraft in support of the Bureau of Land Management conducting aerial reconnaissance and supervision. The airplane was on station for about 45 minutes over the area of the Cedar Basin fire. The ADS-B data showed the airplane had accomplished multiple orbits over the area of the fire about 2,500 ft above ground level (agl). The last ADS-B data point showed the airplane’s airspeed as 151 knots, its altitude about 2,300 ft agl, and in a descent, about 805 ft east southeast of the accident site. No distress call from the airplane was overheard on the radio. According to a witness, the airplane was observed in a steep dive towards the ground. The airplane impacted the side of a ridgeline in mountainous desert terrain. The main wreckage was mostly consumed by a post-crash fire. Debris was scattered over an area of several acres. Another witness observed the left wing falling to the ground after the aircraft had impacted the terrain. The left wing had separated outboard of the nacelle and was located about 0.79 miles northeast of the main wreckage and did not sustain thermal damage.

The twin engine airplane departed Villavicencio-La Vanguardia Airport Runway 05 at 0659LT on a training flight consisting with a proficiency check of the captain. On board were one instructor, one captain and one mechanic. About 10 minutes into the flight, while cruising at an altitude of 6,000 feet over mountainous terrain in Instrument Meteorological Conditions, the airplane impacted trees and crashed on the slope of a hilly terrain located in the region of Restrepo. The wreckage was found three days later. All three crew members were killed.

The pilot was conducting an instrument flight rules cross-country flight and climbing to a planned altitude of 23,000 ft mean sea level (msl). According to air traffic control data, as the airplane climbed through 18,600 ft msl, its groundspeed was 171 knots, and a gradual reduction in groundspeed began. After reaching an altitude of about 20,200 ft msl, the airplane began a descent on a southeast heading. Just before the descent began, the airplane’s groundspeed had decreased to 145 knots. About 2 minutes after the descent began, the airplane turned right to a northeast heading on which it continued for about 30 seconds. The flightpath then became erratic before the data ended. The pilot made no distress calls and did not respond to repeated calls from the controller. The main wreckage of the airplane was located in densely forested terrain at an elevation of about 930 ft about 1,000 ft south of the last radar return. The outboard portion of the right wing, right aileron, right horizontal stabilizer, and right elevator were not located with the main wreckage and, despite ground and aerial searches with a small unmanned aircraft system, were not found. Examination of the wreckage indicated that the missing wing and tail sections separated in flight due to overload. Examination of the recovered airframe and engine did not reveal evidence of any pre-existing mechanical malfunctions or anomalies that would have precluded normal operation. Weather forecasts indicated that the accident site was in an area where moderate icing conditions up to 25,000 ft msl, embedded thunderstorms, and 2-inch hail were forecasted. Review of preflight weather information received by the pilot indicated that he was aware of the conditions forecast on the route of flight before initiating the flight. Meteorological data revealed that the airplane likely entered icing conditions that ranged from light to heavy as it climbed through 14,000 ft msl about 23 minutes after takeoff and remained in icing conditions for the remaining 16-minute duration of the flight. Freezing drizzle conditions were likely present along the flightpath. Although the airplane was equipped for flight in icing conditions, the pilot’s operating handbook contained a warning about flight into severe icing conditions, which stated that flight in freezing drizzle could result in ice build-up on protected surfaces exceeding the capability of the ice protection system. The airplane’s gradual loss of groundspeed as it climbed was consistent with ice accumulating on the airplane. It is likely that during the 16 minutes the airplane was operating in icing conditions, the capability of the ice protection system was exceeded, which resulted in a degradation of aircraft performance and subsequent aerodynamic stall. During the ensuing uncontrolled descent, the structural capability of the airplane was exceeded, which resulted in an inflight break up. A review of the pilot’s records revealed multiple certificate application failures for reasons that included inadequate knowledge of cross-country flight planning, aircraft performance, and stalls. Review of the pilot’s airman knowledge written tests found areas answered incorrectly over multiple exams included meteorology, aircraft performance, aeronautical decision-making, and stalls. The ethanol identified in the pilot’s cavity blood was most likely the result of postmortem production. Therefore, effects from ethanol did not play any role in this accident. The cargo was documented as it was removed from the airplane and remained secure until after it was weighed. Based upon the weight of the cargo, passengers, airplane, and fuel from the filed flight plan, at the time of departure, the airplane would have been about 361 lbs over maximum gross weight. According to the FAA Pilot’s Handbook of Aeronautical Knowledge, an overloaded airplane “may exhibit unexpected and unusually poor flight characteristics,” which include reduced maneuverability and an increased stall speed.