A stabiliser of the Il-86 airliner, which crashed near Sheremetyevo airport, possibly moved to the extreme position due to a malfunction of an electric circuit in the stabiliser control system, a RIA Novosti source in the commission probing into the air crash cause was quoted as saying on Tuesday.
According to him, at present, almost all the aircraft's components necessary to determine the cause of the tragedy have been collected, while data obtained from the flight recorders has been examined.
The source also said that the relevant switch has a duplicate on both pilot wheels. To change the stabiliser's position both buttons should have been pressed. If both buttons operate in the due course, pressing only one of them will give no result. That is why pilots always press both of them.
As to the Il-86, probably one of its buttons was broken. When the second one started malfunctioning, the first button simply failed to brake the circuit, the source said.
There was little time to take a decision - about five or six seconds.
During this period, the pilots managed to get the maximum thrust from the engine /the flight recorders proved this version/ in order to keep up the speed during a rapid pitching up. But the engines were not powerful enough for such an ascend, the RIA Novosti source added.
The Il-86 airliner fell down on July 28th from a 600-metre altitude following a take-off from Sheremetyevo-1 airport /Moscow region/ and caught fire. The aircraft bound from Moscow to St. Petersburg belonged to the Pulkovskiye airlines.
Fourteen out of the sixteen crewmen onboard were killed.