Copterline accident
This accident remains quite a mystery. The team (Sikorsky,
NTSB, Estonian authorities, Turbomeca, etc.) are still unable to find any
"smoking gun" associated with the accident. So far, no technical problem
has been found. The MGB has been examined and nothing abnormal was found their, either.
The U. S. NTSB is giving this accident a high priority and is ready to utilize their full range of resources to try and determine the primary cause of the accident.
Press release__________
Sent: Tue Sep 13 01:08:21 2005
Subject: Estonian investigation commission rules out engine failure as cause of August helicopter crash
Estonian investigation commission rules out engine failure as cause of
August helicopter crash
18:59, 12. september 2005
TALLINN, Sep 12, BNS - A commission set up in Estonia to investigate the crash near Tallinn last month of a helicopter of the Finnish Copterline company has ruled out breaking off of the rotor blade and engine failure as the causes of the accident but has so far failed to establish why the chopper crashed.
"We've a fairly true picture of how everything happened but unfortunately we're unable to say why it happened," the chairman of the Economy and Communications Ministry commission probing into the helicopter accident, Taivo Kivistik, told reporters today.
His deputy, Tonu Ader, said the commission has as a result of the investigation ruled out several earlier theories about possible causes of the accident. He declined to say which versions the investigators consider the more likely so as to avoid speculation.
The probe did not establish the breaking off of some parts while the helicopter was in air, Ader said. The parts separated from the chopper were lying near the wreck on the bottom of the sea and the only part lying farther away from the wreck was a blade of the main rotor.
"The commission has serious grounds to eliminate the breaking off of the main rotor blade as a cause of the crash," Ader said.
According to Ader, the commission reached the conclusion that the blade found at a distance 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 the engines failing during flight. Ader said the engines continued working till almost the moment the helicopter struck water.
The helicopter started behaving inexplicably around 37 seconds before plunging into sea, Ader said. In his words, first its nose lifted up while the helicopter itself started to turn to its left side and away from its original course.
Then the chopper turned back right and started falling, making 13 full turns to the right, or one turn in 2.5 seconds on the average, until it hit water.
"The high speed of turning may indicate an overload which prevented the crew from getting control of the helicopter," Ader said.
According to him, the tape of the discussion between the pilot and the co-pilot showed that right before the zero-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.
A bit later the co-pilot's question, "Have we lost the tail?" could be heard following 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 in order.
The Sikorsky S-76 C+ helicopter operated by Finland's Copterline company plunged into the Baltic Sea on August 10 shortly after taking off from Tallinn for Helsinki, claiming the lives of all the 12 passengers and two pilots on board.
The investigating commission was supposed to publish its interim report today but did not do so because of a petition against it lodged by the families of Estonian victims of the crash.
The commission is to complete its final report within a year of the accident, or by Aug. 10, 2006 at the latest