​​Destruction of engine

In 2010, a ban on the operation of the Tupolev Tu-154 was introduced in Iran. It happened after a disaster that killed 168 people. The final report on it was recently published, but only in Persian. Thanks to enthusiasts who translated it into English.

On July 15, 2009, the Tupolev Tu-154M airliner of Caspian Airlines operated a flight on the Tehran - Yerevan route. The aircraft was produced in 1987 by the Kuibyshev aircraft plant. A month before the disaster, it had proceeded full technical maintenance at the airport of Russian Mineralnye Vody.

During the climb at 8770 meters, fire alarm in engine No. 1 was triggered. Pilot informed the air traffic controller about it. Then plane suddenly changed course and began to fall. Crew did not answer any more calls. The plane crashed in a deserted area and completely destroyed.

The investigation was carried out by the Iranian Aviation Accident Investigation Council (IAAIB) with the participation of Russian specialists. Council immediately established that destruction of engine No. 1 was cause of the crash. Its remains were sent to Russia for examination.

It found that the first stage of the low pressure compressor had a crack due to fatigue of the titanium alloy. This led to the separation of parts of the rotor disc and the destruction of the engine. The scattered parts damaged the hydraulic systems and fuel lines of the other engines. Fuel and hydraulic fluid burst into flames. Fire destroyed the control systems and the crew lost control of the aircraft.

In 2010, a Russian engine manufacturer issued a service bulletin requiring replacement of a low pressure compressor on all engines with more than 8000 operating hours. In this case, they are no longer considered serviceable. The lack of information from the manufacturer about the need for checks and replacements was highlighted as one of the reasons contributing to the disaster. Also, violations were found in the actions of the crew.

The crash investigation report was drawn up in 2011, but it appeared on the IAAIB website only in 2019. And only in Persian. Such actions do not contribute to the improvement of flight safety, since late publication and amateur translations can lead to distortion of meaning and omission of details. The reports must be prepared in the international aviation language - English.