Flight

En route, the crew encountered technical issues and attempted to make a belly landing in a desert and rocky area located in the Hadhramaut. The aircraft came to rest and was damaged beyond repair while all 19 occupants (among them three were injured) were kidnapped by local tribesmen. The exact cause of the technical malfunction remains unknown. The aircraft was on its way to the oil field of Masila that belongs to Canadian Nexen and members of the Yemeni president family.

On 16 February 2014, the Twin Otter (DHC6/300) aircraft with registration number 9N-ABB, owned and operated by Nepal Airlines Corporation (NAC), departed Kathmandu at 0610 UTC (1155 LT) on its schedule flight to Jumla carrying 18 persons on board including 3 crews. Detailed sectors to be covered by the flight No. RA 183/718 was Kathmandu–Pokhara–Jumla-Nepālganj (Night stop). Flight from Kathmandu to Pokhara completed in normal condition. After 17 minutes on ground at Pokhara airport and refueling 9N-ABB departed Pokhara at 0658 for Jumla. After Jumla flight, the aircraft was scheduled to Night stop at Nepālganj. Next day it was to do a series of shuttle flights from Nepālganj. Prevailing westerly weather had a severe impact on most of the domestic flights since last two days. A.M.E. of Engineering Department of NAC who had performed D.I. of 9N ABB had mentioned in his written report to the Commission that he had reminded the diversion of Bhojpur flight of NAC due weather and asked the Captain whether he had weather briefing of the Western Nepal or not. In response to the AME's query the Captain had replied casually that- "weather is moving from west to east and now west is improving". Pilots behavior was reported normal by the ground staffs of Kathmandu and Pokhara airports prior to the commencement of flight on that day. All the pre and post departure procedure of the flight were completed in normal manner. Before departure to Jumla from Pokhara, Pilots obtained Jumla and Bhairahawa weather and seems to be encouraged with VFR Weather at both stations. However, they were unable to make proper assessment of en route weather. PIC decided to remain south of track to avoid the terrain and weather. CVR read out revealed that pilots were aware and concerned about the icing conditions due to low outside air temperature. After around 25 minutes, probably maneuvering to avoid weather, the PIC instructed the co-pilot to plan a route further south of their position, to fly through the Dang valley. The copilot selected Dang in the GPS, on a bearing of 283°, and determined the required altitude was 8500ft. He then raised concerns that the aircraft may not have enough fuel to reach the planned destination. Approximately two and a half minutes before the accident, the PIC initiated a descent, and the copilot advised against this. As per CVR read out, last heading recorded by copilot, approximately one minute before the crash, was 280. The last one minute was a very critical phase of the flight during which PIC said I am entering (perhaps inside the cloud). At that time copilot called Bhairahawa Tower on his own and got latest Bhairahawa weather. While copilot was transmitting its last position report to Bhairahawa Control Tower (approximately 25 miles from Bhairahawa), PIC interrupted and declared to divert Bhairahawa. Bhairahawa Control Tower wanted the pilots to confirm their present position. But crews were very much occupied and copilot said STANDBY. Just few seconds before crash copilot had told PIC not to descend. Copilot also suggested PIC in two occasions - sir don't turn. Very unfortunately aircraft was crashed. The aircraft disintegrated on impact and all 18 occupants were killed.

The twin engine aircraft departed Bucharest-Baneasa Airport on an ambulance flight to Oradea, carrying a medical team, one patient and two pilots. Doctors should go to Oradea to obtain transplant organs from a patient who just passed away. While cruising at an altitude of 6,300 feet vertical to the Apuseni Mountain Range, the crew encountered marginal weather conditions with icing conditions but continued when both engines lost power and failed. The crew attempted an emergency landing when the aircraft collided with trees and crashed in a snowy and wooded hillside at an altitude of 1,400 metres. A pilot and a passenger were killed while five other occupants were injured. The aircraft was destroyed.

The twin engine aircraft was performing a special mission with a crew of two and a member of the ISAF on board. The accident occurred in unknown circumstances somewhere in the east part of Afghanistan. The aircraft was destroyed and all three occupants were killed. There are no indications that the aircraft was brought down by enemy fire, said a Defense official. It was later reported that the airplane involved was completing an Air Medium-Altitude Reconnaissance and Surveillance System (MARSS) mission.

The captain and first officer were conducting an international cargo flight in the twin-engine turboprop airplane. After about 40 minutes of flight during night visual meteorological conditions, an air traffic controller cleared the airplane for a descent to 7,000 ft and then another controller further cleared the airplane for a descent to 3,000 ft and told the flight crew to expect an ILS (instrument landing system) approach. During the descent, about 7,300 ft and about 290 kts, the airplane entered a shallow left turn, followed by a 45-degree right turn and a rapid, uncontrolled descent, during which the airplane broke up about 1,500 ft over uneven terrain. The moderately loaded cargo airplane was not equipped with a flight data recorder or cockpit voice recorder (CVR) (although it previously had a CVR in its passenger configuration) nor was it required by Federal Aviation Administration (FAA) regulations. There were also no avionics on board with downloadable or nonvolatile memory. As a result, there was limited information available to determine what led to the uncontrolled descent or what occurred as the flight crew attempted to regain control of the airplane. Also, although the first officer was identified in FAA-recorded radio transmissions several minutes before the loss of control and it was company policy that the pilot not flying make those transmissions, it could not be determined who was at the controls when either the loss of control occurred or when the airplane broke up. There was no evidence of any in-flight mechanical failures that would have resulted in the loss of control, and the airplane was loaded within limits. Evidence of all flight control surfaces was confirmed, and, to the extent possible, flight control continuity was also confirmed. Evidence also indicated that both engines were operating at the time of the accident, and, although one of the four propeller blades from the right propeller was not located after separating from the fractured hub, there was no evidence of any preexisting propeller anomalies. The electrically controlled pitch trim actuator did not exhibit any evidence of runaway pitch, and measurements of the actuator rods indicated that the airplane was trimmed slightly nose low, consistent for the phase of flight. Due to the separation of the wings and tail, the in-flight positions of the manually operated aileron and rudder trim wheels could not be determined. Other similarly documented accidents and incidents generally involved unequal fuel burns, which resulted in wing drops or airplane rolls. In one case, the flight crew intentionally induced an excessive slide slip to balance fuel between the wings, which resulted in an uncontrolled roll. However, in the current investigation, the fuel cross feed valve was found in the closed position, indicating that a fuel imbalance was likely not a concern of the flight crew. In at least two other events, unequal fuel loads also involved autopilots that reached their maximum hold limits, snapped off, and rolled the airplane. Although the airplane in this accident did not have an autopilot, historical examples indicate that a sudden yawing or rolling motion, regardless of the source, could result in a roll, nose tuck, and loss of control. The roll may have been recoverable, and in one documented case, a pilot was able to recover the airplane, but after it lost almost 11,000 ft of altitude. During this accident flight, it was likely that, during the descent, the flight crew did regain control of the airplane to the extent that the flight control surfaces were effective. With darkness and the rapid descent at a relatively low altitude, one or both crewmembers likely pulled hard on the yoke to arrest the downward trajectory, and, in doing so, placed the wings broadside against the force of the relative wind, which resulted in both wings failing upward. As the wings failed, the propellers simultaneously chopped through the fuselage behind the cockpit. At the same time, the horizontal stabilizers were also positioned broadside against the relative wind, and they also failed upward. Evidence also revealed that, at some point, the flight crew lowered the landing gear. Although it could not be determined when they lowered the gear, it could have been in an attempt to slow or regain control of the airplane during the descent. Although reasons for the loss of control could not be definitively determined, the lack of any preexisting mechanical anomalies indicates a likelihood of flight crew involvement. Then, during the recovery attempt, the flight crew's actions, while operating under the difficult circumstances of darkness and rapidly decreasing altitude, resulted in the overstress of the airplane.

Aircraft left Maputo Airport at 1126LT on flight LAM470 to Luanda, Angola. En route, while overflying Botswana and Namibia, aircraft encountered bad weather conditions with CB's at high altitude and turbulence. In unknown circumstances, aircraft went out of control and disappeared from radar screens at 1230LT, most probably after diving into the ground. As the aircraft did not arrive at Luanda, SAR commenced but were suspended by night due to low visibility and bad weather conditions (heavy rain falls). The day after, on 30NOV, Namibia Police forces announced they located the wreckage in the Bwabwata National Park, near Divundu. Aircraft was completely destroyed by impact forces and post impact fire. All 33 occupants were killed, among them 16 Mozambicans, 9 Angolans, 5 Portuguese, one French, one Brazilian and one Chinese. The aircraft crashed in a dense wooded and isolated area, sot SAR are difficult. No distress call was sent by the crew.

The airplane departed Annecy-Meythet Airport at 1033LT on a flight to Toussus-le-Noble, carrying five passengers and one pilot. The flying time was approximately one hour under IFR mode. At 1111LT, while cruising at FL180 near Auxerre, heading to EBOMA, the pilot informed ATC he was ready for the descent. He was cleared to descend to FL120 when the aircraft started to drift to the left of the airway. Two minutes later, ATC informed the pilot about the deviation and the pilot acknowledged and initiated a turn to the right when control was lost. The airplane entered a dive and reached an excessive vertical speed until it crashed in an open field. The airplane disintegrated on impact and all six occupants were killed.

The twin engine aircraft departed Monterrey-Del Norte Airport at 0820LT on a flight to Xalapa-El Lencero Airport, Veracruz. While cruising in marginal weather conditions, the airplane crashed in the Sierra Madre Oriental, near the summit of Mirador. The aircraft was destroyed by a post crash fire and both occupants were killed.

At approximately 1830 hrs on 3 November 2013 the operator’s duty pilot received a request that the aircraft should be dispatched to carry out a search. The volunteer crew-members were alerted and made their way to the airport. Weather conditions in the Channel Islands were poor, with a southerly wind gusting up to 41 kt, turbulence, rain, cloud below 1,000 ft aal, and visibility of 3 to 6 km. On arrival at the aircraft’s hangar, the crew was established, consisting of a pilot, search director, and three observers. They donned immersion suits and life jackets and prepared for flight. The search director obtained details of the search request, which was to search for two fishermen near Les Écréhous (a group of rocks in the English Channel approximately 5 nm north-east of the north-eastern corner of Jersey). Some evidence suggested the men were in a small dinghy; other information was that they were in the water. The men were reported to be alive and communicating by mobile telephone. One crew-member carried out pre-flight preparations, although he did not check the fuel quantities or carry out a water drain check. When interviewed, he recalled having reported to the pilot that he had not checked the fuel. The aircraft was then pulled out of its hangar and the search director explained the details of the search request to the pilot and other crew-members. Bearing in mind the weather, the fact that it was dark, and the fishermen’s predicament, the pilot recognized the need for “a lot of urgency” about the task. In the context of the operation, he regarded the task as being routine, but the weather not so. The pilot “walked round” the aircraft, though he did not carry out a formal pre-flight inspection; it was the organization’s custom to ensure that the aircraft was ready for flight at all times. The technical log showed that the aircraft was serviceable, with no deferred defects, and that the wing tanks contained 55 USG each side and the tip tanks, 18 USG each side. The search director recalled asking the pilot whether he was content to fly in the prevailing conditions, and that the pilot stated that he was willing to fly. The crew boarded the aircraft. The observer in the front right-hand seat had recently obtained a Private Pilot’s Licence and this influenced the decision for him to be placed next to the pilot. The pilot reported that he carried out a “fairly rapid” start, although the normal pre-departure sequence was interrupted while a problem with switch selections, affecting the functioning of the search equipment in the aircraft’s cabin, was resolved. The pilot obtained clearance from ATC to taxi, enter the runway, and take off when ready. He described that he carried out engine power checks during a brief back-track, checking the magnetos and propeller controls at 2,100 rpm, before carrying out pre-takeoff checks. He did not refer to the written checklists provided in the aircraft but executed a generic set of checks from memory. Following an unremarkable takeoff, in the strong crosswind , the pilot corrected for drift and established a climb towards a cruising altitude of 900 ft. When interviewed, he described the conditions as being “awful” and “ghastly”, with turbulence from the cliffs contributing to occasional activation of the stall warner, even though the speed was “probably 100 plus knots” . At 900 ft, the aircraft was “in the bottom” of the cloud, which was unhelpful for the observers, so the pilot descended the aircraft to cruise at 500 or 600 ft, flying by reference to the artificial horizon, and making constant control inputs to maintain straight and level flight. He stated that, although he would normally have begun checking fuel flow, mixture settings, etc, shortly after establishing in the cruise, he found that the conditions required him to devote his full attention to flying the aircraft. As the aircraft passed north abeam the western end of Jersey, the rain and low cloud continued and the turbulence worsened, The pilot gained sight of red obstacle lights on a television mast on the north side of the island but had few other visual references. The pilot noticed a change in an engine note. He immediately “reached down to put the hot air on” which made little difference; the observer recalled that the pilot checked that the mixtures were fully rich at this time. The right-hand engine rpm then began surging. The pilot made a quick check of the engine instruments, before applying full throttle on both engines, setting both propellers to maximum rpm and beginning a climb. The observer noticed that the fuel pressure gauge for the right-hand engine was “going up and down” but did not mention this to the pilot; the pilot did not see the gauge indication fluctuating. Around this time the pilot switched the electric fuel pumps on. The pilot turned the aircraft towards Jersey and made a MAYDAY call to ATC; the search director made a similar call on the appropriate maritime frequency. These calls were acknowledged, and a life boat, on its way to Les Écréhous, altered course towards the aircraft’s position. Although the pilot was “amazed” at how few lights he could see on the ground, he perceived what he thought was the runway at Jersey Airport, and flew towards it. The aircraft reached approximately 1,100 ft amsl. The right-hand engine then stopped. The pilot carried out the shut-down checks, feathering the propeller as he did so. The aircraft carried on tracking towards Jersey Airport, descending towards the north side of the island. Some moments later, the left-hand engine’s rpm began to fluctuate briefly before it also stopped. The pilot later recalled being “fairly certain” that he “was trying to change tanks” but acknowledged that he could not recall events with certainty. He trimmed the aircraft for a glide, still heading towards the airport at Jersey, but with very limited visual references outside the cockpit. The crew-members prepared the cabin for a ditching or off-airport landing; the observers in the rear-most seats considered how they might deploy the aircraft’s life raft (stored behind their seats) should a ditching occur. The pilot’s next recollection was that the automated decision height voice call-out activated (he had selected it to announce at 200 ft radio height). He switched the landing lights on and maintained a “reasonable speed” in anticipation of landing or ditching. One crew-member recalled the pilot calling “brace, brace, brace”, while another recalled being instructed to tighten seat belts and brace. No brace position had been set out in the operations manual, or rehearsed in training, and the responses of the crew-members to this instruction varied. The pilot glimpsed something green in front of the aircraft, and flared for landing. The aircraft touched down and decelerated, sliding downhill and passing through a hedge. With the aircraft now sliding somewhat sideways, it came to a halt when its nose lodged against a tree, with significant airframe damage. The pilot made various cockpit selections safe and all the occupants vacated the aircraft, with some difficulty. The search director became entangled in his headset lead as he egressed but freed himself. The front seat occupants experienced difficulty because their door could not be opened. They climbed over the search director’s desk and vacated the aircraft via the door adjacent to the search director’s position (the rear-row observers simultaneously opened the pilot’s door from the outside). The pilot and crew made their way to nearby habitation where they were subsequently assessed by an ambulance crew; none were injured. The search director returned to the aircraft with fire-fighters, to ensure that pyrotechnics and the self-inflating life raft on board the aircraft did not pose a hazard. In his very frank account of the flight, the pilot acknowledged that a decision to turn back soon after departure would have been justified by the weather conditions. He added that before the engine power changed, his workload was already very high, on account of the task and conditions.

On 19 October 2013, the Pilatus Porter was being used for parachute drops. The day started normally with the first take-off at 07:21. Each flight transported 9 or 10 passengers. Except for the first two, all the flights of that day were conducted by the same pilot. The aircraft’s last landing in EBNM was at 13:20 to board the next group of 10 parachutists. After the take-off, the aircraft appeared again on the radar at 13:28 at an altitude of 1200 ft. At 13:28:52, the EBCI Air Traffic Control Officer (ATCO) instructed the aircraft to remain at 2000 ft AMSL to allow for crossing traffic, a B737 landing at EBCI, and to proceed further to the east. After the crossing, the Pilatus was authorized to climb to 5000 ft. At 13:33:32, when the aeroplane was flying at 4400 ft, the pilot was authorized to turn back to the drop zone and turned towards its target, the EBNM airfield. Shortly after, a witness observed the aeroplane making a wide turn to the left. This witness monitored the aeroplane for about 40 seconds. He indicated the engine was making an abnormal noise which he compared with the explosions made by the exhaust of a rally car when decelerating. Finally, the witness heard a loud explosion ending by the dive of the aeroplane. He believed that the sound of an explosion was caused by the “engine turbine disintegration”. Another witness driving on the E42 highway saw the aeroplane performing what he perceived as being some aerobatic manoeuvers. The aeroplane was diving and was spinning. A moment later, he saw the wing break-up, including the separation and falling of smaller parts. A sailplane pilot was standing in his garden not far from the crash site. He first heard the sound of the Pilatus which he described as being typical, smooth and constant. He looked at the aeroplane and noticed it was flying at a lower altitude than usual. He stopped observing after a few seconds. 30 to 40 seconds later, he heard an abnormal noise change which he thought was a propeller pitch change or an engine power change. He looked for the aeroplane in the sky and saw the aeroplane diving with an angle of more than 45° immediately followed by a sharp pull-out angle of over 70°, followed by the upwards breaking of a wing. The aeroplane went down “as in a stall”. The witness still heard “the sound of propeller angle moving” after the wing separation. Another witness standing approximately at an horizontal distance of 600 m from the aeroplane described having heard a sound change. He looked at the aeroplane and saw the aeroplane flying horizontally, making several significant left and right roll movements of the wings before it disappearing from his view. The aeroplane crashed on a field in the territory of Gelbressée, killing all occupants. The aeroplane caught fire shortly after the impact. A big part of the left wing, elements thereof and the right sliding door of the cabin were found at 2 km from the main wreckage. Of the aircraft’s occupants, 4 parachutists were ejected from the aircraft just prior to impact.