TALLINN - A helicopter accident in the Bay of Tallinn in August 2005 that claimed 14 lives was caused by a fault in the machine's operating system, the commission set up to investigate the accident says in its interim report.
"The reason why the helicopter met with an emergency situation was a malfunction in its operating system that developed in the third minute of the flight, which in turn was caused by a failure in the main rotor's front servo," the commission said.
Investigators explained that the servo fault caused made the chopper virtually impossible to control using ordinary piloting procedures.
The servo malfunction did not trigger an alarm signal and because of that the pilots were unable to take the necessary special measures.
The investigation established that the helicopter did not survive its impact with the water. The crew had the necessary licenses and competence to perform the flight, the helicopter's flight fitness certificate was valid and the aircraft was provided with the necessary equipment and quantities of fuel and lubricants. Its flight weight and balance were within normal limits, and the weather conditions were in line with requirements, the commission said.
"In those particular circumstances, the persons on board the helicopter had no chance of surviving," the investigators state.
The commission will make additional flight safety recommendations arising from the crash in its final report.
The Sikorsky S-76C+ owned by the Copterline company and operated by a Finnish crew crashed into the Bay of Tallinn minutes after take-off while on a scheduled commercial flight from Tallinn to Helsinki on Aug. 10, 2005. All 12 passengers and two crew on board the helicopter were killed.