10 August 2005 helicopter crash near Tallinn
Encyclopedia
Copterline Flight 103 (AAQ103) was a Copterline
helicopter flight en route to Helsinki
, Finland
from Tallinn
, Estonia
that crashed into the sea on August 10, 2005, at 12:45 pm local time.
The Sikorsky S-76C+
crash occurred three to four minutes after taking off. On board were two Finnish crew members and 12 passengers: six Finns, four Estonians and two America
ns. There were no survivors.
The helicopter was flying at an altitude of about 500 metres when it suddenly lost its steerability and plunged into the sea. The emergency floats failed to operate, and the wreck sank quickly. All those on board perished by drowning.
The Sikorsky S-76C+ has emergency pontoons for water landing
s but they were not deployed, and no distress signal
s were heard before the crash, although it later emerged that the pilots had tried to send an emergency message shortly before the crash.
Rescuers reached the site in less than 10 minutes to find just one main rotor blade and an oil slick on the water. The wreckage of the helicopter itself was located by sonar
operators on the Estonian Maritime Administration
vessel EVA-320, who indicated that the aircraft was intact at a depth of roughly 43 meters. Two Estonian deep-sea divers following an earlier unmanned robotic vehicle reported that the bodies of the passengers were inside the craft. Thirteen bodies were retrieved, with one pilot missing. The recovery mission was hindered by rough weather conditions. The wreckage of the aircraft was lifted on August 13, 2005 and transported to Tallinn for investigation. The missing pilot was not found in the initial searches performed by the Estonian and Finnish authorities, but the body was finally located on August 25 and retrieved by volunteer divers some distance away from the accident site. The post mortem indicated that the victims died from drowning
.
The Estonian authorities refused to send the flight data recorder
of the helicopter to the United States
because the aircraft was manufactured there, thus possibly creating a conflict of interest
. The technical investigation was in fact performed in the United Kingdom
. The voice recording indicated that the pilots realized that something was wrong only 35 seconds before the helicopter hit the sea, and that they did attempt to send a Mayday
message.
The accident investigation board published a preliminary report on September 14, 2005, in which they ruled out most possibilities of physical damage before the helicopter hit water, including sabotage and collision with a flock of birds. As the helicopter was manufactured in the United States, the U.S. National Transportation Safety Board
(NTSB) has taken part into the investigation. In November 2005 NTSB issued an "urgent" recommendation to the FAA that it require all S-76 operators to carry out "immediate visual and laboratory examinations" of main rotor servos for plasma flakes and other contamination. The helicopter manufacturer, Sikorsky Aircraft
, rejected these findings, saying it and servo manufacturer HR Textron "do not agree that the servo caused the mishap". In December 2005 the company, however, issued an all-operators letter recommending that operators carry out internal leakage tests of all S-76 main rotor servos, at the same time emphasizing that testing with an intentionally degraded servo "has not identified any safety of flight issues".
The talks between Copterline and Sikorsky Aircraft about how to divide damages arising from the crash broke down in December 2006, and Copterline sued Sikorsky Aircraft in a U.S. court in New York for damages of 60 million US dollars.
In August 2007 it was announced that the cause of the crash was a failure of the hydraulic flight control system, caused by coating flaking off from servo pistons. The loosened plasma coating flakes blocked the return valves of the servos, causing the aircraft to abruptly lose its maneuverability. Copterline did not have the authority to service or even open these components. However, in the final report, Copterline was criticized for omitting a periodic leak test of the hydraulic flight control system that could have revealed the problem. The Finnish authorities were also criticized for insufficient supervision.
Copterline
Copterline Limited was Finland's largest helicopter airline. In 2004 the company ferried over 75,000 passengers. On December 19, 2008, Copterline confirmed that it had ceased its scheduled service between Helsinki and Tallinn. On 15 February 2010, Copterline filed for bankruptcy, citing inability...
helicopter flight en route to Helsinki
Helsinki
Helsinki is the capital and largest city in Finland. It is in the region of Uusimaa, located in southern Finland, on the shore of the Gulf of Finland, an arm of the Baltic Sea. The population of the city of Helsinki is , making it by far the most populous municipality in Finland. Helsinki is...
, Finland
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...
from Tallinn
Tallinn
Tallinn is the capital and largest city of Estonia. It occupies an area of with a population of 414,940. It is situated on the northern coast of the country, on the banks of the Gulf of Finland, south of Helsinki, east of Stockholm and west of Saint Petersburg. Tallinn's Old Town is in the list...
, Estonia
Estonia
Estonia , officially the Republic of Estonia , is a state in the Baltic region of Northern Europe. It is bordered to the north by the Gulf of Finland, to the west by the Baltic Sea, to the south by Latvia , and to the east by Lake Peipsi and the Russian Federation . Across the Baltic Sea lies...
that crashed into the sea on August 10, 2005, at 12:45 pm local time.
The Sikorsky S-76C+
Sikorsky S-76
The Sikorsky S-76 is an American medium-size commercial utility helicopter. The S-76 is powered by two turboshaft engines, which drive both the main and tail rotors, each with four blades...
crash occurred three to four minutes after taking off. On board were two Finnish crew members and 12 passengers: six Finns, four Estonians and two America
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
ns. There were no survivors.
The helicopter was flying at an altitude of about 500 metres when it suddenly lost its steerability and plunged into the sea. The emergency floats failed to operate, and the wreck sank quickly. All those on board perished by drowning.
The Sikorsky S-76C+ has emergency pontoons for water landing
Water landing
A water landing is, in the broadest sense, any landing on a body of water. All waterfowl, those seabirds capable of flight, and some human-built vehicles are capable of landing in water as a matter of course....
s but they were not deployed, and no distress signal
Distress signal
A distress signal is an internationally recognized means for obtaining help. Distress signals take the form of or are commonly made by using radio signals, displaying a visually detected item or illumination, or making an audible sound, from a distance....
s were heard before the crash, although it later emerged that the pilots had tried to send an emergency message shortly before the crash.
Rescuers reached the site in less than 10 minutes to find just one main rotor blade and an oil slick on the water. The wreckage of the helicopter itself was located by sonar
Sonar
Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...
operators on the Estonian Maritime Administration
Estonian Maritime Administration
The Estonian Maritime Administration is a governmental agencythat operates within the area of government of the Ministry of Economic Affairs andCommunications, has a directing function, exercises state supervision and applies...
vessel EVA-320, who indicated that the aircraft was intact at a depth of roughly 43 meters. Two Estonian deep-sea divers following an earlier unmanned robotic vehicle reported that the bodies of the passengers were inside the craft. Thirteen bodies were retrieved, with one pilot missing. The recovery mission was hindered by rough weather conditions. The wreckage of the aircraft was lifted on August 13, 2005 and transported to Tallinn for investigation. The missing pilot was not found in the initial searches performed by the Estonian and Finnish authorities, but the body was finally located on August 25 and retrieved by volunteer divers some distance away from the accident site. The post mortem indicated that the victims died from drowning
Drowning
Drowning is death from asphyxia due to suffocation caused by water entering the lungs and preventing the absorption of oxygen leading to cerebral hypoxia....
.
Flight data recorder
A flight data recorder is an electronic device employed to record any instructions sent to any electronic systems on an aircraft. It is a device used to record specific aircraft performance parameters...
of the helicopter to the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
because the aircraft was manufactured there, thus possibly creating a conflict of interest
Conflict of interest
A conflict of interest occurs when an individual or organization is involved in multiple interests, one of which could possibly corrupt the motivation for an act in the other....
. The technical investigation was in fact performed in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
. The voice recording indicated that the pilots realized that something was wrong only 35 seconds before the helicopter hit the sea, and that they did attempt to send a Mayday
Mayday (distress signal)
Mayday is an emergency procedure word used internationally as a distress signal in voice procedure radio communications. It derives from the French venez m'aider, meaning "come help me"....
message.
The accident investigation board published a preliminary report on September 14, 2005, in which they ruled out most possibilities of physical damage before the helicopter hit water, including sabotage and collision with a flock of birds. As the helicopter was manufactured in the United States, the U.S. National Transportation Safety Board
National Transportation Safety Board
The National Transportation Safety Board is an independent U.S. government investigative agency responsible for civil transportation accident investigation. In this role, the NTSB investigates and reports on aviation accidents and incidents, certain types of highway crashes, ship and marine...
(NTSB) has taken part into the investigation. In November 2005 NTSB issued an "urgent" recommendation to the FAA that it require all S-76 operators to carry out "immediate visual and laboratory examinations" of main rotor servos for plasma flakes and other contamination. The helicopter manufacturer, Sikorsky Aircraft
Sikorsky Aircraft
The Sikorsky Aircraft Corporation is an American aircraft manufacturer based in Stratford, Connecticut. Its parent company is United Technologies Corporation.-History:...
, rejected these findings, saying it and servo manufacturer HR Textron "do not agree that the servo caused the mishap". In December 2005 the company, however, issued an all-operators letter recommending that operators carry out internal leakage tests of all S-76 main rotor servos, at the same time emphasizing that testing with an intentionally degraded servo "has not identified any safety of flight issues".
The talks between Copterline and Sikorsky Aircraft about how to divide damages arising from the crash broke down in December 2006, and Copterline sued Sikorsky Aircraft in a U.S. court in New York for damages of 60 million US dollars.
In August 2007 it was announced that the cause of the crash was a failure of the hydraulic flight control system, caused by coating flaking off from servo pistons. The loosened plasma coating flakes blocked the return valves of the servos, causing the aircraft to abruptly lose its maneuverability. Copterline did not have the authority to service or even open these components. However, in the final report, Copterline was criticized for omitting a periodic leak test of the hydraulic flight control system that could have revealed the problem. The Finnish authorities were also criticized for insufficient supervision.