Copterline Flight 103
Sikorsky S-76C+ · Servo failure
Event
- NTSB case
- DCA05RA089
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Unknown · led by another country; figures from NTSB notifications
- Event fatalities
- 14 · all aircraft and ground
- Ground fatalities
- Unknown
- Occupants
- 14
- Survivors
- 0
- InjuriesFatal: death within 30 days. Serious: over 48 hours in hospital within a week, most broken bones, severe bleeding, nerve or organ damage, or serious burns. Minor: anything less. Glossary
- 0 serious · 0 minor (NTSB)
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Not recorded
Sikorsky S-76C+
- Flight
- AAQ103
- Aircraft type
- Sikorsky S-76
- Category
- Helicopter · from aircraft type
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- OH-HCI
- Operator
- Copterline
- Onboard fatalities
- 14
- Route
- From not recordedTo not recorded
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Non-U.S., Commercial
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Not recorded
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Not recorded
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Not recorded
Cause areas
- Aircraft › Aircraft systems
- Aircraft › Aircraft handling/service
- Organizational issues › Support/oversight/monitoring
From the investigation findings the Wikipedia article reports, sorted into the NTSB's cause areas with AI assistance.
Approximate · Coordinates from the Wikipedia article; not checked against an investigation report.
From the Wikipedia article
Copterline Flight 103 (AAQ103) was a Copterline helicopter flight en route to Helsinki, Finland from Tallinn, Estonia that crashed into the Tallinn Bay on 10 August 2005, at 12:45 local time.
The Sikorsky S-76C+ crash occurred three to five minutes after taking off. On board were two Finnish crew members and twelve passengers: six Finns, four Estonians and two Americans. There were no survivors.
Crash
The crew members were 41-year-old Captain Peter Fredriksson, he had 7,068 hours of flight time, with 173 of these on the Sikorsky S-76; and First Officer Seppo Peurala, aged 56, had accumulated 7,618 hours of helicopter flight time, of which just over 258 hours were on the Sikorsky S-76.
The helicopter was flying at an altitude of about 500 m when it suddenly lost its steerability and plunged into the sea. The emergency floats didn't inflate in time and the wreck sank quickly. All those on board perished by drowning.
The Sikorsky S-76C+ emergency pontoons for water landings were deployed but couldn't inflate in time, no distress signals were heard, 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 m. 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 13 August 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 25 August and retrieved by volunteer divers some distance away from the accident site. The post mortem indicated that the victims died from drowning.
Investigation and cause
Investigation
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 instead 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 14 September 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 in the investigation. In November 2005, the NTSB issued an "urgent" recommendation to the FAA to 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.
Text from the Wikipedia article “Copterline Flight 103” (revision 1365115421, retrieved 2026-09-18) by its authors, under CC BY-SA 4.0. Extracted as plain text: references, tables, images and some sections are left out. Read the article
Sources
Wikipedia article: Copterline Flight 103
- Article
- Copterline Flight 103
- Revision
- 1365115421 · 2026-07-20 · retrieved 2026-09-18
- Wikidata
- Q3737036
- Licence
- Text CC BY-SA 4.0, by the article's authors; Wikidata CC0; town positions GeoNames (CC BY 4.0)
NTSB record DCA05RA089
- Event ID
- 20050825X01308
- Case number
- DCA05RA089
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Where each value comes from
- Record
- Wikipedia article "Copterline Flight 103" (page 2421864, revision 1365115421); merged with NTSB case DCA05RA089 (events / aircraft)
- Date
- Wikipedia infobox: date
- Place and country
- Wikipedia infobox: site
- Map position
- Wikipedia: Wikipedia article coordinates
- Aircraft, operator and route
- Wikipedia infobox: aircraft type, registration, operator, origin and destination; route airports from the linked airport articles' Wikidata codes (OurAirports); gaps and aircraft details from NTSB record DCA05RA089
- Operation
- airline flight number in the infobox
- Fatalities
- Wikipedia: Wikipedia infobox: aircraft fatalities
- Ground fatalities
- Wikipedia: not stated in the Wikipedia infobox
- Summary
- Wikipedia infobox: summary
Source notes (2)
- One occurrence in two sources, merged: the Wikipedia article "Copterline Flight 103" and NTSB case DCA05RA089, matched by the same aircraft registration and date. For this event outside the United States Wikipedia's values are used where the two differ; each value names its source.
- No bulk values were replaced by the NTSB case API.