Mountains

The Britten Norman “Islander” aircraft, registration G-CHES, had flown on the morning of 17 October 2007 over various points of the Sierra Morena and the north part of the province of Seville. Its mission had been to scout the various flight fields which would be available to the aircraft in future operations. The purpose of that day’s flight was to land at a temporary runway in the town of Guadalcanal, in the province of Seville on the border with the province of Badajoz. This runway, used by airplanes on agricultural flights, is some five kilometers SW of the town. The pilot, however, mistakenly landed at another temporary field, with the same bearing and approximately halfway between the town and the other runway on Guadalcanal. The runway on which it landed, called Los Tomillares (after the name of the ranch on which it is located), is considerably shorter. The distance available was sufficient for the airplane’s sole pilot to land normally. In order to be able to depart from that strip, which measured only 400 m in length, the pilot telephoned for help and guidance in order to make the short four-kilometer flight from that strip to the runway in Guadalcanal, his original destination. In response to his call for help, a pilot with experience on that type of airplane reported to the strip early in the afternoon and joined the pilot as a crew advisor on the aircraft in order to aid the pilot in command. Two other persons on the ground provided assistance loading fuel in the main tanks. The gasoline was taken to the aerodrome in 50-liter plastic drums, which were placed inside the aircraft once emptied, since they were operating between runways in which there was no refueling service. A total of 250 liters of AV100LL fuel was deposited in the main tanks. Both pilots walked the length of the field at Los Tomillares to check its condition and dimensions. They determined its length by counting their steps. They also determined its gradient. Although the surface was made of uncompacted dirt, they calculated that it was sufficient for takeoff, which they decided to do toward the southeast to take advantage of the favorable negative slope. Specifically, they planned to depart on a SE heading, turn 90° right, and continue flying south until they were lined up with the Guadalcanal runway. They planned to land on a NW course. They postponed the operation until late in the afternoon, before sunset, so as to avoid glare from the setting sun while landing at Guadalcanal. According to eyewitness accounts, the pilot in command did the pre-flight check and dismissed the ground assistants, who left before the airplane took off. A few minutes later, at 19:30, half an hour prior to sunset, the aircraft headed for the runway threshold. Shortly thereafter it started its takeoff, gaining speed and becoming airborne prior to reaching the opposite threshold. The right engine then started to fail partially, causing the airplane to yaw hard to the right. The pilot in command, seated to the left, was flying the airplane. According to the statement of the accompanying pilot, who was seated in the RH seat, when the engine failed, the pilot asked him to take the flight controls while he attempted to restore power to the right engine. After lowering the nose, they started to descend slightly, managing to correct the right yaw by applying left rudder. They had practically managed to regain directional control of the aircraft when the right engine started to run at full power once more, propelling the aircraft, which caused it to veer left, toward higher ground. They were unable to avoid the impact. The aircraft’s left wingtip impacted first, hitting some bushes on the hillside. A few meters later the left gear wheel made contact. After crossing a small river bed, the aircraft’s left wing and forward fuselage impacted, with the airplane coming to a stop after traveling along the ground for a few meters. The impact site was on the runway centerline extension and some 400 m from the southeast threshold, which they had overflown a few seconds earlier when taking off. The aircraft was seriously damaged and was essentially destroyed. There was no fire after the impact.

The twin engine aircraft departed Villavicencio-La Vanguardia Airport at 1530LT on a flight to Uribe with 15 passengers and 2 pilots on board. En route, while cruising in poor weather conditions, the crew reported his ETA in Uribe at 1550LT. At an altitude of 11,800 feet, the aircraft struck the slope of a mountain and disintegrated on impact. The wreckage was found 3 days later on Mt Páramo El Nevado, about 33 km northeast of Cubarral. The aircraft was totally destroyed upon impact and all 17 occupants were killed.

The pilot was returning a group of skydivers to their home base after a weekend of skydiving. He flew several jump flights, and then stopped early in the afternoon to prepare the airplane for the flight home. The flight was planned into an area of clouds, turbulence, and icing, which the pilot had researched. He delayed the departure until he decided that he could complete the planned flight under visual flight rules (VFR). The accident occurred at night with little illumination of the moon, and the airplane was in an area of layered clouds. A detailed analysis of the weather conditions revealed that the flight probably encountered broken to overcast layers both below and above its flight altitude. The satellite and sounding images suggested that it was possibly in an area of mountain wave conditions, which can enhance icing. The recorded radar data indicated that the pilot was likely maneuvering to go around, above, or below rain showers or clouds while attempting to maintain VFR. The airplane likely entered clouds during the last 3 minutes of flight, and possibly icing and turbulence. It was turning when it departed from controlled flight, and a performance study showed that the angle-of-attack at this point in the flight was increasing rapidly. The study determined that the
departure from controlled flight was consistent with an aerodynamic stall. The unpressurized airplane was flying at over 14,000 feet mean sea level for more than 1 hour during the flight. It reached 15,000 feet just prior to the accident in sequential 360-degree turns while climbing and descending. Supplemental oxygen was not being used. At these altitudes, the pilot would be substantially impaired by hypoxia, but would have virtually no subjective symptoms, and would likely be unaware of his impairment. The pilot had logged over 2,000 hours of total flight time, with nearly 300 hours in this make and model of airplane. He was instrument rated, but had only logged a total of 2 hours of actual instrument flight time. Company policy was to fly under visual flight rules only, and they had not flight-checked the pilot for instrument flight.

The pilot contacted air traffic control, using the wrong call sign, requesting radar flight following. The airplane initially climbed to 13,500 feet, descended to 11,500 feet, climbed to 13,500 feet, and then began a descent until it impacted terrain at 11,900 feet. One minute prior to impact, the pilot asked the air traffic controller about various minimum altitudes for his route of flight. The controller responded with a minimum instrument altitude of 15,000 to 15,300 feet. A review of the handling of the accident flight showed that the controller was aware of the airplane's position, altitude, general route of flight, and its proximity to terrain. No safety alert was issued to the accident flight. Weather depiction charts, infrared satellite imagery, and local weather observations indicate instrument meteorological conditions prevailed along the route of flight, closest to the accident location. The moon had set at 1539 on the day of the accident. The pilot reported a planned flight altitude of 12,500 feet to his dispatcher. No record of a preflight weather briefing was located. An examination of the airplane, engines, and related systems revealed no anomalies.

The pilot was ferrying the aircraft under the visual flight rules (VFR) from the operator’s base at Tully, Qld to Ingham and return. The flights, conducted in the private category without passengers, were to allow aircraft maintenance to be conducted at Ingham. The flight from Tully to Ingham was conducted in the morning, with no reported difficulties. At 1454 Eastern Standard Time, the pilot departed Ingham on the return flight to Tully. The aircraft did not arrive at Tully. It was not until the next day that the pilot and aircraft were reported missing. Australian Search and Rescue (AusSAR) was notified and a search, based on the last air traffic control radar observed position of an unidentified aircraft from a replay of recorded radar data together with witness reports from the area, was initiated. Searchers located the aircraft wreckage on the morning of 18 August. The aircraft had impacted mountainous terrain in a state forest 24 km south of Tully. The pilot was fatally injured and the aircraft was destroyed.

At 1946 Eastern Standard Time on 31 July 2007, a Rockwell International Aero Commander 500S, registered VH-YJB (YJB), departed Essendon Airport, Vic. on a business flight to Shepparton that was conducted at night under the instrument flight rules (IFR). On board were the pilot and one passenger. At 1958, while in the cruise at 7,000 ft above mean sea level (AMSL) in Class C controlled airspace, radar and radio contact with the aircraft was lost simultaneously by air traffic control when it was about 25 NM (46 km) north-north-east of Essendon. The air traffic controller declared a distress phase after a number of unsuccessful attempts to contact the pilot. At 2003, the Operations Director at Melbourne Centre declared the aircraft as probably lost and advised AusSAR. A search was commenced using a helicopter and an aeroplane in addition to ground search parties. No emergency locator transmitter signal was reported. At 2147, aircraft wreckage was located by a searching aircraft in timbered ranges near Clonbinane, approximately 50 km north of Melbourne. At about 2200, a ground search party confirmed that the wreckage was that of YJB and that there were no survivors. The flight was arranged to take the company owner, who was also a licensed aircraft maintenance engineer (LAME), to Shepparton to replace an unserviceable starter motor in another of the operator‟s aircraft. The pilot, who had landed at Essendon at 1915 from a previous flight in another of the operator‟s aircraft, was tasked to fly the owner to Shepparton. The pilot transferred to YJB, which had previously been prepared for flight by another company pilot. At 1938, while taxiing for takeoff, the pilot advised the aerodrome controller of the intention to conduct the IFR flight, adding, „…and request a big favour for a submission of a flight plan, with an urgent departure Essendon [to] Shepparton [and] return‟. The aerodrome controller did not have the facilities for processing flight notifications and sought the assistance of a controller in the Melbourne air traffic control centre. There were no eyewitnesses to the accident. Residents living in the vicinity of the accident site were inside their homes and reported difficulty hearing anything above the noise made by the wind and the foliage being blown about. One of the residents reported hearing a brief, loud engine noise. Another resident thought the noise was that of a noisy vehicle on the road. The noise was described as being constant, „…not spluttering or misfiring‟ and lasted for only a few seconds. Some of those residents near the accident site reported hearing and feeling an impact only moments after the engine noise ceased. The aircraft was seriously damaged by excessive in-flight aerodynamic forces and impact with the terrain. The vegetation in the immediate vicinity of the main aircraft wreckage was slightly damaged as the aircraft descended, nearly vertically, through the trees. The pilot and passenger were fatally injured.

The crew departed Pescara-Liberi Airport at 1719LT on a fire fighting mission in the Sirente-Velino Regional Natural Park under callsign CAN19. While approaching the area under fire, the aircraft initiated a slight turn to the right when it collided with the top of a hill and disintegrated, bursting into flames. The wreckage was found at an altitude of 1,155 metres near Acciano. While the copilot was seriously injured, the captain was killed.

The aircraft departed Siem Reap Airport on a flight to Sihanoukville, carrying 16 passengers (13 South Korean and 3 Czech) and 6 crew members. While descending to Sihanoukville Airport in marginal weather conditions, the aircraft struck the slope of Mt Phnom Damrey located in the Elephant Mountain Range, about 50 km northeast of the Sihanoukville Airport. The aircraft was totally destroyed and all 22 occupants were killed.

The crew departed Bishkek on a special flight to Issyk Kul and Naryn to proceed with the calibration of the ILS systems. About 30 minutes into the flight from Issyk Kul to Naryn, the right engine started to vibrate while the left engine temperature increased. After the right engine was shut down, the captain asked the flight engineer to reduce the power on the left engine by 80%. While flying in the Karakuzhur Valley and unable to maintain a safe altitude, the pilot remembered he was using in the past an old dirt strip for agricultural operations as he was flying Antonov AN-2. He attempted to land on this airstrip located at an altitude of 2,700 metres. Upon landing, the aircraft collided with rocks (larger than 40 cm) and drainage ditches and came to rest, bursting into flames. All 14 occupants escaped uninjured while the aircraft was destroyed.

The Twin Otter departed Iquitos Airport at 1137LT on a flight to Pucallpa with intermediate stops in Requena, Orellana, Pampa Hermosa and Contamana. While descending to Pampa Hermosa in marginal weather conditions, the aircraft crashed in a mountainous area located few km from the airport. Seven passengers were rescued while 13 other occupants were killed.