The Ministry of Economy and Communications has published an interim report by the commission investigating last month's Copterline helicopter crash, which claimed 14 lives, on their ministry Web site at http://www.mkm.ee.
On Sept. 13, families and friends of the victims withdrew a petition they had previously formed against publicizing the report.
"We've dropped the petition," barrister Leon Glikman from the Teder, Glikman & Partners law firm, who was representing the victims' families, told the Baltic News Service. "The reason is that the report does not contain privacy-invading personal data, and does not touch our client's interests."
Meanwhile, the investigation commission has assured the public that the 19-page document does not contain a description of the victims' state. The page describing victim injuries was dropped.
The document does, however, list known facts about how the accident happened, while describing damage to the helicopter and including data from the recovered "black box." The investigators said that, prior to the crash, the helicopter showed no disorders. The reason why the chopper flew out of control remains unclear.
Days earlier, the commission announced that its investigation had ruled out a broken rotor blade and engine failure as causes of the accident. An official cause, however, has not yet been established.
"We've a fairly true picture of how everything happened, but unfortunately we're unable to say why it happened," commission chairman Taivo Kivistik told reporters.
His deputy, Tonu Ader, said the commission had ruled out several earlier theories about possible causes of the accident. Yet he declined to say which versions the investigators consider the more likely.
"The commission has serious grounds to eliminate the breaking-off of the main rotor blade as a cause of the crash," Ader said.
Rotor blade parts were discovered near the wreck on the bottom of the sea. One blade from the main rotor was lying further from the pile.
According to Ader, the commission concluded that the blade found far from the wreck did not break off until the helicopter hit water. He made it clear that all four blades had broken off and had sustained relatively similar damage.
The commission also ruled out the possibility of an engine failure during the flight. The deputy commissioner said the engines were working until almost the moment the helicopter struck water.
The helicopter began having problems about 37 seconds before plunging into sea, Ader said. First the helicopter's nose lifted upward, while the body itself started to turn left - away from its original course.
The chopper then turned right and started falling, making 13 full turns to the right, or one turn in 2.5 seconds on average, until it hit water.
"The high speed of turning may indicate an overload, which prevented the crew from gaining control of the helicopter," Ader said.
The investigator added that a taped discussion between the pilot and the co-pilot showed that, right before the moment when things started to go wrong, the pilot said, "Let's boost power," which was followed by an expression of surprise and, a few seconds later, by a very quiet "Mayday" call repeated three times.
Moments later, the co-pilot's question, "Have we lost the tail?" could be heard, after which the recording contained no distinguishable phrases, he said.
According to Ader, clear evidence exists that the helicopter's tail rotor continued turning until the chopper hit water, and that the aircraft's hydraulic systems were working as expected.
The commission is supposed to complete a final report within one year, or by Aug. 10, 2006 at the latest.
The Sikorsky S-76C+ helicopter, operated by the Finnish company Copterline, plunged into the Baltic Sea on Aug. 10 shortly after taking off from Tallinn for Helsinki. All 12 passengers and two pilots on board were killed in the accident.