Scheduled Revenue Flight

On approach to Dembidolo by night and stratus clouds, the crew failed to realize his altitude was too low. While facing a mountain, the crew increased engine power to gain height but the aircraft stalled, lost altitude and crashed on a hilly terrain located few km from the airfield. All 20 occupants were injured while the aircraft was damaged beyond repair.

Crashed in unknown circumstances after the crew got distracted in flight.

On June 18, 1986, at 0855 mountain standard time, a Grand Canyon Airlines DHC-6, N76GC (Twin Otter), call sign Canyon 6, took off from runway 21 of the Grand Canyon Airport. The flight, a scheduled air tour over Grand Canyon National Park, was to be about 50 minutes in duration. Shortly thereafter, at 0913, a Helitech Bell 2068 (Jet Ranger), NGTC, call sign Tech 2, began its approximate 30-minute, on-demand air tour of the Grand Canyon. It took off from its base at a heliport adjacent to State route 64 in Tusayan, Arizona, located about 5 miles south of the main entrance to the south rim of the National Park. Visual meteorological conditions prevailed. The two aircraft collided at an altitude of 6,500 feet msl in the area of the Tonto Plateau. There were 18 passengers and 2 flightcrew members on the DHC-6 and 4 passengers and 1 flightcrew member on the Bell 206B. All 25 passengers and crew members on both aircraft were killed as a result of the collision. Because of the lack of cockpit voice recorders and flight data recorders in both aircraft, as well as the lack of radar data, no assessment of the flight path of either aircraft could be made. As a result, the reason for the failure of the pilots of each aircraft to “see and avoid” each other cannot be determined. Consequently, the issues highlighted in this report concern primarily the oversight of the Federal Aviation Administration (FAA) on Grand Canyon-based scenic air tours or sightseeing flights and the actions of the National Park Service to influence these operations. Because of an exemption to 14 Code of Federal Regulations (CFR) Part 135, local scenic air tours were conducted under 14 CFR Part 91. This investigation revealed that there was no FAA oversight on the routes and altitudes of Grand Canyon-based scenic air tour operators. This was contrary to the intent of Safety Recommendation A-84-52. Further, the National Park Service, through its authority under a 1975 law, was conducting a study to determine the effects of aircraft noise on the Grand Canyon and, at the same time, influencing the selection of air tour routes. The routes of the rotary-wing operators were ‘moved as a noise conservation measure to where they converged with those of Grand Canyon Airlines at the location of the accident. Other safety issues concern the lack of regulations to limit flight and duty times of pilots conducting scenic air tour flights, and the lack of a requirement for the pilots of such flights to use intercoms or public address systems when narrating during the flights. All 20 occupants of the Twin Otter were killed, among them 11 citizen from The Netherlands and two Swiss.

Loganair Flight LC423 was a scheduled passenger flight from Glasgow Airport (GLA) to Islay/Port Ellen (ILY). The handling pilot, who occupied the first pilot's position, had recently converted to flying the DHC-6 Twin Otter aircraft, and was completing a series of supervised route flights required by the airline before the award of full command status. A company supervisory captain, the designated commander for this flight, occupied the co-pilot's position. The Twin Otter's engines were started at 14:38, and, at 14:44, Glasgow Airport ATC approved taxy clearance to the holding point of runway 28. The aircraft was operating on a stored Instrument Flight Rules (IFR) flight plan. The requested routeing was a Standard Instrument Departure (SID), to join Airway Blue 2 for the Skipness VOR beacon, and thereafter direct to the Islay/Port Ellen NDB. The direct track is the 272° Magnetic (M) radial from Skipness. At 14:46 Glasgow ATC advised LC423 of their flight clearance. The requirement to fly the SID was cancelled and the aircraft was cleared direct to Skipness, cruising level FL55. The aircraft took off from runway 28 at 14:48. The aircraft reported a position overhead the Skipness VOR at 15:08. At this point Scottish Airways Control informed LC423 that they should clear controlled airspace, contact Port Ellen, and that there was no known traffic to affect their descent. After passing overhead the Skipness VOR the aircraft did not depart that position on the 272° radial, but instead turned 15° left, and descended on the 257° radial towards the south of the island of Islay. At 15:10, having already started to descend, LC423 contacted Islay/Port Ellen, reported an arrival time of 15:23, and requested details of the latest weather. The Islay/Port Ellen radio operator replied that the weather details were a surface wind of 220°/05 knots, visibility 2000 metres in drizzle, cloud 3 oktas at 400 feet, 5 oktas at 700 feet, and 8 oktas at 1400 feet. The sea level barometric pressure was 1018 millibars. LC423 acknowledged the information and was asked to advise when overhead the aerodrome at 3600 feet, or when in visual contact. The aircraft then continued to descend, on a track of about 260° M towards the south of the island, until it disappeared from radar cover at a height of 1400 feet and at a position 12 nautical miles (nm) from Islay/Port Ellen aerodrome on the 106° M radial. From the position that the aircraft descended below radar cover it is estimated that a direct track was flown towards the southern coast of the Isle of Islay. The flight continued at very low level parallel to the south coast. At 15:21 the Islay/Port Ellen radio operator transmitted further weather information which recorded that cloud conditions were similar to the previous report but that there was then heavy drizzle. Changes in barometric pressure settings were also reported. LC423 acknowledged this information and reported "over Port Ellen". However, the aircraft was not, at that time, over Port Ellen, but was in fact turning inland at very low level over Laphroaig. From overhead Laphroaig the aircraft settled on to a northwesterly heading and very shortly afterwards crashed into rising ground, that was obscured in hill fog, approximately 1 nm from the coast at a height of 360 feet amsl.

On approach to Cairo-Intl Airport, the crew encountered poor weather conditions due to sandstorm. On final, the aircraft descended below the glide when it struck the roof of a building and crashed in an industrial estate located short of runway. Three passengers were seriously injured while 23 other occupants were killed.

On approximately 25-May-1986, the aircraft landed on lake ice at Reliance, NWT; while taxiing the nose gear settled into a crack in the ice. The people of the community managed to prevent the aircraft from sinking further using pallets and empty drums. While the insurance company assessed methods of possibly removing the aircraft it continued to sink, eventually to a depth where only the tail remained above water. A military Chinook helicopter was eventually dispatched to Reliance, and it successfully lifted the aircraft out of the lake, and set it down in front of the weather station pending preparations to sling load it 143 nm to Yellowknife. After lift off, and a distance of approximately 200 yards the helicopter's load master elected to drop the aircraft, which plowed nose first into the lake, through the remaining lake ice. Some parts were salvageable and barged back to Yellowknife, however the aircraft was a total loss.
Text & photos : www.twinotterworld.com

Following an uneventful flight from Chelyabinsk to Moscow in relative good weather conditions, the crew started the descent to Moscow-Domodedovo when the weather conditions worsened. While descending to an altitude of 3,600 meters, the aircraft entered an area of heavy rain falls and icing (a cold front was passing over Moscow at that time). The Pitot tubes became obstructed, modifying some instruments settings. The airspeed indicator fell to zero and the crew thought the aircraft was near stall conditions so he initiated an emergency descent with a rate of descent of 100 meters per second and a speed of 813 km/h. The aircraft encountered positive acceleration of 3,2 g and suffered structural damages. The crew was able to divert to Moscow-Sheremetyevo Airport where an emergency landing was completed. All 185 occupants evacuated safely and the aircraft was later declared as damaged beyond repair due to irreparable damages to the main structure (fuselage).

This part 135 IFR flight was inbound for landing at Laramie, Wyoming. During the en route and approach for landing portions of the flight the aircraft picked up a moderate to heavy load of ice. During the landing flare the aircraft stalled, hit the runway, bounced, veered off the runway, and struck a VASI lighting system. The left landing gear collapsed and the aircraft skidded to a stop. All nine occupants escaped uninjured while the aircraft was damaged beyond repair.

While parked at Colombo-Bandaranaike Airport, the aircraft was preparing for the last leg to Male. Ground personnel was still servicing the aircraft with fuel and catering and about 150 people were on board when an explosion occurred in the rear part of the cabin. The aircraft was cut in two and partially destroyed by fire. 46 people were injured, 88 were unhurt and 16 passengers were killed.

The twin engine aircraft was cruising at an altitude of 8,500 feet in marginal weather conditions when it struck the slope of a mountain located about 18 km east of Tame, some 50 km south of Saravena. The aircraft was destroyed and all 13 occupants were killed.