Aircraft and Flight Information
The aircraft involved was a Boeing B737-800, registration EI-CXV, serial number 32364, manufactured on 3 July 2002. It was equipped with two CFM56-7-B26 engines. The operator was MIAT (Mongolian Airlines), and the flight was a charter service from Incheon, South Korea to Ulaanbaatar, Mongolia.
History of the Flight
On 2 July 2020, the aircraft departed Incheon at 02:23 UTC. At 02:40 UTC, it reached an altitude of 33,300 feet and a speed of 268 knots. At 02:56 UTC, air traffic control instructed the crew to climb to 10,400 meters. Between 02:56:34 and 02:56:37, during the climb, the left engine experienced a sudden reduction in rotational speed: N1 dropped from 100.6% to 54.9%, and N2 dropped from 97% (exact value not fully reported). The left engine had shut down in flight.
Persons on Board and Injuries
There were 174 persons on board: 7 crew members and 167 passengers. No injuries were reported.
Damage
The left engine sustained damage.
Crew Information
The commander was a 33-year-old male holding an Airline Transport Pilot Licence (ATPL) with 7,904 total flight hours. The co-pilot's details were not specified in the report.
Investigation
The Civil Aviation Authority of China (CAAC) declined to investigate the incident. In accordance with Annex 13 to the Convention on International Civil Aviation and the Civil Aviation Law of Mongolia, the Aircraft Accident Investigation Bureau (AAIB) of Mongolia conducted the investigation. The incident was classified as a serious incident. The National Transportation Safety Board (NTSB) of the United States provided support as the state of design and manufacture.
Probable Cause
The final report did not specify a probable cause for the engine shutdown.