Incident Overview
On December 10, 2019, a Mi-8AMT helicopter operated by Mongolian Alt LLC (MAK) took off from Ulaanbaatar Chinggis Khaan International Airport at 10:46 local time. The aircraft, registered as JU-6600, was scheduled for a flight to Ulan-Ude. Shortly after takeoff, while climbing to an altitude of approximately 3,570 meters, the crew observed abnormal indications regarding the rotation and temperature of the right engine.
Crew Response and Landing
In response to the engine malfunction, the pilot in command shut down the right engine. The helicopter then turned back toward Ulaanbaatar Chinggis Khaan Airport. The aircraft landed safely on a single engine at 11:08 local time. No injuries were reported among the four crew members or four technical staff on board.
Aircraft and Engine Details
The helicopter is a Mi-8AMT model with manufacturer serial number 8AMT00496114709U, built in 2011 at the Mil factory in Ulan-Ude. It was delivered to Mongolian Alt LLC in October 2011. At the time of the incident, the airframe had accumulated 655.16 flight hours and 568 flight cycles.
The affected right engine is a TV3-117VM Series 02 model with manufacturer serial number K788520780. Manufactured on December 20, 2007, the engine had logged 1,183.27 flight hours and 1,114 cycles by the date of the incident. The engine's operational life limit had been extended to December 20, 2019, following a technical assessment in late 2017 that found no discrepancies in its condition.