Widerøe Flight 839, also known as the Værøy Accident ( no, Værøy-ulykken), was a
de Havilland Canada DHC-6-300 Twin Otter that crashed shortly after take-off from
Værøy Airport
Værøy Airport ( no, Værøy lufthavn; ) was a regional airport located just southwest of the village of Nordland on the island of Værøya in Værøy Municipality in Nordland county, Norway. Operated between 1986 and 1990, it had an asphal ...
in
Norway
Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...
. The incident occurred on 12 April 1990 at 14:44, killing all five people on board. The cause of the accident were strong winds that exceeded the structure's tolerance, causing the
tail rudder and
tailplane
A tailplane, also known as a horizontal stabiliser, is a small lifting surface located on the tail (empennage) behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed-wing aircraft such as helicopters and gyroplane ...
to crack so the plane became uncontrollable. Impact occurred 63 seconds after take-off and 8 seconds after the crack. The aircraft crashed into the water, and a search was conducted for several days to find the wreck.
Uneven and strong winds had given the airport low regularity, and prior to take-off, wind speeds of had been recorded. The accident caused the airport to be permanently closed, and replaced by
Værøy Heliport
Værøy Heliport ( no, Værøy helikopterhavn; ) is a heliport located at Tobbisodden on the island of Værøya in Værøy Municipality in Nordland county, Norway. The heliport lies close to the village of Sørland, the municipal centre of the m ...
. The incident was investigated by the
Accident Investigation Board Norway
The Norwegian Safety Investigation Authority (NSIA; no, Statens havarikommisjon, SHK) is the government agency responsible for investigating transport-related accidents within Norway. Specifically, it investigates aviation accidents and incident ...
, which published its conclusions in 1991. Three years later, a new investigation was conducted, after an engineer had stated that the cause of the accident could instead have been
fatigue
Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...
. The second investigation came to the same conclusion as the first and all involved parties have since supported the causes made in the initial report.
Accident
Widerøe Flight 839 was a scheduled flight from
Værøy Airport
Værøy Airport ( no, Værøy lufthavn; ) was a regional airport located just southwest of the village of Nordland on the island of Værøya in Værøy Municipality in Nordland county, Norway. Operated between 1986 and 1990, it had an asphal ...
to
Bodø Airport
Bodø Airport ( no, Bodø lufthavn; ) is a civil airport in the town of Bodø in Bodø Municipality in Nordland county, Norway. Located just south of the city centre, on the westernmost tip of the Bodø peninsula, it shares facilities with the m ...
operated with a de Havilland Canada DHC-6-300 Twin Otter. The aircraft had registration LN-BNS and serial number 536, and was delivered to Widerøe on 27 April 1977. It was insured with
Norsk Flyforsikringspool Norsk Flyforsikringspool was an insurance pool created by Norwegian
Norwegian, Norwayan, or Norsk may refer to:
*Something of, from, or related to Norway, a country in northwestern Europe
* Norwegians, both a nation and an ethnic group native t ...
. The aircraft left Bodø Airport at 13:36 as Flight 838 to
Røst Airport
Røst Airport ( no, Røst lufthavn; ) is a regional airport serving Røst Municipality in Nordland county, Norway. The airport is located on the northern edge of the main island of Røstlandet, just north of the main village of Røstlandet. I ...
, where it landed at 14:04. It continued to Værøy as Flight 839, leaving Røst at 14:14. During this flight the crew received information that the wind at the east end of the runway was from 270°, varying from —a
moderate gale. When the plane landed at 14:30, the tower had stated that the wind was from 270° and max . The crew commented on the wind after landing, and stated that the wind blew from all directions. At Værøy Airport, three passengers disembarked, two passengers boarded and the plane fueled. There was also a passenger in transit from Røst to Bodø, so the total ridership was three passengers, plus the two pilots. Take-off weight was , including of fuel.
The aircraft taxied to runway 25. During the departure briefing, the captain decided not to follow the company's standard procedure and have a
climb at 320° instead of 280°. Maximum measured wind had been recorded at while the aircraft had been parked. The aircraft asked for clearance at 14:42:10; this was granted, and the air control informed that the wind at the west end was between 210° and 290°, varying from . The eastern wind was not communicated to the aircraft, but was 270°, varying from . The take-off started at 14:42:43 and the aircraft was airborne after having passed half the runway. Witnesses described that the aircraft after take-off climbed quickly, but then started falling, and then climbed quickly again. It then entered clouds west of the airport. During climb, the captain wanted to keep the
flap
Flap may refer to:
Arts, entertainment, and media
* ''Flap'' (film), a 1970 American film
* Flap, a boss character in the arcade game ''Gaiapolis''
* Flap, a minor character in the film '' Little Nemo: Adventures in Slumberland''
Biology and he ...
s at 10°, contradictory to standard procedure that involved decreasing the flaps. At 14:43:09, a rattling sound was registered on the
cockpit voice recorder
A flight recorder is an electronic recording device placed in an aircraft for the purpose of facilitating the investigation of aviation accidents and incidents. The device may often be referred to as a "black box", an outdated name which has b ...
(CVR). Thirty-five seconds later, sounds from unsynchronized propellers were registered. The co-pilot indicates that the flight was in difficulty. Eight seconds later, at 14:43:52, the CVR stopped recording. At 14:43:54, the control tower at Værøy registered a distress signal, that lasted four seconds, followed by a loud bang. The aircraft was then repeatedly called by radio. At 14:50,
Bodø Air Traffic Control Center
Bodø Air Traffic Control Center or Bodø ATCC en route air traffic control unit located at Bodø Airport in Bodø, in North Norway.
The ATCC has a total of 36 airports under its area of responsibility (AoR) - 13 controlled and 23 uncontrolled, re ...
was contacted.
[Accident Investigation Board Norway, 1991: 7–8]
The
Joint Rescue Coordination Centre of Northern Norway in Bodø dispatched two helicopters and two ships, but one helicopter and one ship had to return due to the bad weather that soon had increased to a hurricane. At 16:45, parts of the aircraft were found northwest of Værøy Airport.
After the weather improved, one rescue ship, four fishing vessels and one
Westland Sea King
The Westland WS-61 Sea King is a British licence-built version of the American Sikorsky S-61 helicopter of the same name, built by Westland Helicopters. The aircraft differs considerably from the American version, with Rolls-Royce Gnome engin ...
were used to find the wreck. On 13 April, twelve ships and two helicopters were being used, and several parts from the wreck were found. This allowed the search crew to use divers to search for the wreck.
The aircraft was found on 15 April, from the airport. Eighty percent of the wreck was found within an area of and at about depth.
The deceased were Captain Idar Nils Persen (40), Co-pilot Arnt Vidar Grønneflåta (31), and passengers Stig Myrvoll (25), Frank Bakkeli (27) and Runa Dagny Søraa (23).
All passengers died immediately upon impact, but the Captain's body was never found.
Cause
![Former airport on Værøy, Norway](https://upload.wikimedia.org/wikipedia/commons/f/f1/Former_airport_on_V%C3%A6r%C3%B8y%2C_Norway.jpg)
The runway at Værøy Airport, that runs east–west, ran parallel to a mountain to the south that is about tall. Prior to construction, Widerøe had performed test flights in the area, and these had concluded with unacceptable wind conditions, particularly from the south over the mountain. From 31 October 1988, Widerøe introduced self-imposed restrictions on landing at Værøy. Aircraft were not allowed to land or take off if the wind came from 090°–240° (though south) if the wind speed exceeded , including gusts. Additional restrictions were introduced following an incident on 18 January 1989; these were again modified on 1 November 1989. Flight 839 took off within the permitted limits of these restrictions. However, Twin Otters were not to operate on the ground during winds that exceeded , and since the aircraft started taxiing following a report of wind speeds of , this was a breach of procedure. The wind also changed direction immediately after take-off.
The aircraft had not had any mechanical or technical errors or problems prior to take-off. The
turbulence
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to a laminar flow, which occurs when a fluid flows in parallel layers, with no disruption between ...
and
wind shear
Wind shear (or windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizontal ...
caused a crack in either the tail rudder, the tailplane, or both. This was caused by strong winds acting on both sides of the structure, due to shifting winds. These structural failures caused the aircraft to crash. Out of the 63 seconds from take-off to impact, the aircraft was under control for the first 55 seconds; only during the last 8 seconds did the crew not have control over the aircraft.
The
Accident Investigation Board Norway
The Norwegian Safety Investigation Authority (NSIA; no, Statens havarikommisjon, SHK) is the government agency responsible for investigating transport-related accidents within Norway. Specifically, it investigates aviation accidents and incident ...
stated in its report that the crew should not have landed with the amounts of wind that were reported, and that they definitively should not have taken off. However, since the wind came from the west, which by pilots was reported to cause fewer problems than from other directions, they may have decided to ignore the wind exceeding the permitted values. In particular, the Accident Investigation Board criticized the choice of taxiing in , above the permitted wind speed for ground operation and far over the permitted levels for take-off from the airport. The board commented that although it was common to cancel flights to Værøy, no flights had been canceled after the plane had landed, instead being canceled prior to landing. The board commented that the flight being the last before
Easter
Easter,Traditional names for the feast in English are "Easter Day", as in the '' Book of Common Prayer''; "Easter Sunday", used by James Ussher''The Whole Works of the Most Rev. James Ussher, Volume 4'') and Samuel Pepys''The Diary of Samuel ...
, it may have influenced the pilots' sense of duty towards getting the passengers to their destinations. This may have been aggravated by the very low regularity that was at Værøy. The board also commented that pilots did not trust the wind data they received, since they often experienced it to be incorrect and that the wind could vary considerably within the airport. While the plane was at the ground, it had been raining. Pilots at Værøy often experienced that weather was better between rain showers, and there were indications that the captain wanted to take-off before the next rain shower hit.
The Accident Investigation Board concluded:
The cause of the accident is that the plane during climb was subject to wind that exceeded the plane's construction criteria. This caused a crack in the tail rudder/tailplane causing the plane to become uncontrollable."
Aftermath
New airport
Værøy Airport had opened on 1 July 1986 as part of the regional airport network in Northern Norway. Prior to this, Værøy and Røst had been served by helicopters using a heliport; that had replaced previous services with
seaplane
A seaplane is a powered fixed-wing aircraft capable of takeoff, taking off and water landing, landing (alighting) on water.Gunston, "The Cambridge Aerospace Dictionary", 2009. Seaplanes are usually divided into two categories based on their tec ...
s. All services to the airport were suspended immediately after the incident. On 7 May, Widerøe stated that they would not use Værøy Airport, and that they would decline the
concession
Concession may refer to:
General
* Concession (contract) (sometimes called a concession agreement), a contractual right to carry on a certain kind of business or activity in an area, such as to explore or develop its natural resources or to opera ...
to operate to Værøy if the island community did not receive a new airport. They commented that the restrictions caused by the wind forced the airline to terminate up to half the departures.
The chairman of the Widerøe's Pilots' Union, Cpt. Helge Høvik, stated the same day that the airline might have to lower the number of calls at some other regional airports, namely
Mosjøen Airport, Kjærstad
Mosjøen (; sma, Mussere) is a List of towns and cities in Norway, town in Vefsn Municipality in Nordland county, Norway. Mosjøen is the oldest town in the Helgeland region, with only the Bodø (town), town of Bodø being older within Nordland c ...
,
Mo i Rana Airport, Røssvold,
Sandnessjøen Airport, Stokka
Sandnessjøen is a town and the administrative centre of Alstahaug Municipality in Nordland county, Norway. Sandnessjøen was granted special trading privileges in the late 1600s and it received town status in 1999. Sandnessjøen is located on ...
and
Sandane Airport, Anda
Sandane Airport ( no, Sandane lufthavn; ) is a regional airport serving the village of Sandane in Vestland county, Norway. It perpendicularly straddles the Anda peninsula in Gloppen Municipality between the Nordfjorden and Gloppefjorden. The air ...
. Høvik stated that he felt that many of the airports were located in the wrong place, for instance at the bottom of valleys, on top of hills and between mountains. Widerøe stated that there was not a safety problem at any other regional airports.
The report from the Accident Investigation Board was highly critical to the
Norwegian Civil Aviation Administration, stating that the airport should never have been built where it was and that it was "clearly unsuitable for regular traffic". It stated that the administration had overlooked comments from meteorologists and test flights in the area that had concluded that the wind conditions in the area were not suitable for an airport. The commission that wrote the report and conducted the investigation, stated that the Civil Aviation Administration had not proceeded correctly while planning the airport—they had chosen Nordlandet early as a location and ignored negative comments. After the
Norwegian Meteorological Institute
The Norwegian Meteorological Institute ( no, Meteorologisk institutt), also known internationally as MET Norway, is Norway's national meteorological institute. It provides weather forecasts for civilian and military uses and conducts research in ...
had made a favorable report about the weather in the area, the administration had failed to conduct the necessary test flights to test the wind conditions, since this was not determined in the initial recommendation. The commission also commented that the safety division had been critical to the localization of the airport, but had withdrawn their disputes following pressure from higher ranks in the administration. The commission also criticized the Civil Aviation Administration for not conducting investigations following the reports of low regularity and the incidents in 1988 and 1989.
No aircraft has ever taken off from Værøy Airport after the accident, except in June 1992, when a Cessna 172 brought 3 skydivers from Bodø Skydiving Club (Bodø Fallskjermklubb) to the island, accompanied by a Piper Cherokee 140 from Bodø Flyklubb and an experimental plane. The Cessna made 2 landings and take-offs, and dropped the skydivers over the runway at approx. 8000 feet. The Piper and experimental craft made at least one landing and take-off each, during a public show held close to the airport. In 1992, the
Norwegian Ministry of Transport and Communications The Royal Norwegian Ministry of Transportation (; ) is a Norwegian ministry established in 1946, and is responsible for transportation in Norway. The ministry was responsible for communication infrastructure until may 2019, when the responsibility f ...
decided to permanently close the airport, after it had been temporarily closed since the accident. In 1995,
Værøy Heliport
Værøy Heliport ( no, Værøy helikopterhavn; ) is a heliport located at Tobbisodden on the island of Værøya in Værøy Municipality in Nordland county, Norway. The heliport lies close to the village of Sørland, the municipal centre of the m ...
was opened further south on the island, and
Helikopter Service
CHC Helikopter Service, previously CHC Norway, CHC Helikopter Service and Helikopter Service is the Norwegian division of CHC Helicopter Corporation. The airline was an independent company until 1999. It operates primarily to oil platforms on ...
was awarded the
public service obligation to operate the route. The helicopter service sometimes uses the closed airport as a reserve airport during bad weather.
Second investigation
In an article published in the newspaper ''
Fremover ''Fremover'' is a regional newspaper published in Narvik, Norway
Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Sca ...
'' (Narvik, Norway), in May 1994, the English aviation engineer Hugh Tyrer stated that the cause of the accident was probably due to
fatigue
Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...
in the end piece of the transfer mechanism to the
elevator
An elevator or lift is a wire rope, cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or deck (building), decks of a building, watercraft, ...
. The end piece was in such a state that it would have failed sooner or later in ordinary use. Following this discovery in the wreck, Widerøe had grounded all their Twin Otters and checked these pieces, but without finding any other defect parts.
de Havilland Canada
De Havilland Aircraft of Canada Limited is an aircraft manufacturer with facilities formerly based in the Downsview area of Toronto, Ontario, Canada. The original home of de Havilland Canada was the home of the Canadian Air and Space Museum loca ...
had also sent an alert to all operators of the Twin Otter to check the component, and had canceled the contract with the subcontractor. On 800 operating Twin Otters, 86 end pieces were replaced shortly after the accident, although none had fatigue similar to that of LN-BNS. The commission's chair, Ragnar Rygnestad, stated that they had not considered the end piece to be part of the cause of the accident, and that they therefore had not stress-tested it or the elevator to see what forces were needed to cause a crack. Rygnestad stated that the board knew about the fatigue. He also said that he had no problems with the opening of a new inquiry. Widerøe stated that they trusted the report from the Accident Investigation Board.
Member of parliament,
Inge Myrvoll, and president of the
Norwegian Airline Pilots Association
The Norwegian Airline Pilots Association ( no, Norsk Flygerforbund, NF) is a trade union of civil airline pilots in Norway.
It was established as a merger in 1977. It has about 850 members, and has its headquarters in Drammensveien at Skillebekk, ...
, Cpt. Peter Helland, both stated that the Accident Investigation Board should make a new inquiry about the accident. Cpt. Helland stated that the report's credibility was weakened due to the influence de Havilland Canada had during the process.
On 10 June, the commission reopened the case, after having held meetings with Tyrer. The commission stated that there was disagreement as to if the tail rudder and tail plane or the end piece had cracked first, which would be crucial in determining the cause of the accident. Among the inquiries would be to re-investigate the tape of cockpit sound with new technology. The Accident Investigation Board used the
National Aerospace Laboratory in the Netherlands to conduct tests on the end pieces. The report from the National Aerospace Laboratory was published on 23 March 1995, and supported the conclusion in the commissions report. The journalist Oddvar Kristoffersen in ''Fremover'' won the
SKUP Award
SKUP Award (''SKUP-prisen'') is a Norwegian journalism award.
It has been awarded annually since 1990 by the Norwegian Foundation for a Free and Investigative Press (''Stiftelsen for en Kritisk og Undersøkende Presse'') or SKUP.The award is a cu ...
for 1994 for his work related to uncovering the controversy. The pilots' union in Widerøe was initially critical of the report, but by July it stated that it supported the conclusion. In addition,
Det Norske Veritas
DNV (formerly DNV GL) is an international accredited registrar and classification society headquartered in Høvik, Norway. The company currently has about 12,000 employees and 350 offices operating in more than 100 countries, and provides ser ...
withdrew its critical comments concerning the commission. With this, all officially involved parties supported the report.
References
Bibliography
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{{DEFAULTSORT:Wideroe Flight 839
Aviation accidents and incidents in 1990
Aviation accidents and incidents in Norway
1990 in Norway
Widerøe accidents and incidents
Værøy
Accidents and incidents involving the de Havilland Canada DHC-6 Twin Otter
Airliner accidents and incidents caused by in-flight structural failure
April 1990 events in Europe