(Adds detail from Russian transport agency, industry source)
Sept 21 (Reuters) - The United Arab Emirates' (UAE) civil aviation regulator is investigating why an Emirates Airbus A380 superjumbo flew dangerously low when approaching Moscow's Domodedovo Airport last week.
The General Civil Aviation Authority (GCAA) said its air accident investigation unit is treating the Sept. 10 episode as a serious incident, an internationally recognized category which means an accident nearly occurred.
The GCAA said Emirates flight EK131 "descended below the glideslope on approach," meaning that the aircraft flew below the recommended height as it came into land.
The Aviation Herald reported that the aircraft descended to 400 feet at 8 nautical miles (14.8 kilometers) from the runway, before pulling out of the approach and later landing safely, but only after a second unsuccessful attempt.
The typical height for a passenger jet at that distance would be more than 2,000 feet, an aviation expert said.
The pilots told air traffic control "everything is fine" when contacted by operators after the incident, and later said "everything is great" following the second unsuccessful landing attempt, a Russian industry source with direct knowledge of the matter said.
No injuries to the 426 passengers and crew onboard or damage to the aircraft was reported, the GCAA said.
A spokeswoman for Emirates, which says it operates two daily flights to Moscow, confirmed the flight was under investigation, but declined to comment further.
Emirates has not raised any concerns about Russian air traffic control or airport equipment relating to the incident, Russias Rosaviatsia federal air transport agency said.
Flight information has been handed to the GCAA and the airline, the Russian agency said, adding that it was not conducting its own investigation.
The incident comes amid a probe into the Emirates crash landing at Dubai International Airport in 2016 which is looking at the actions of the pilots, the GCAA said on Aug. 6.
All 300 passengers and crew evacuated, but a firefighter died tackling a fire after the plane skidded along the runway.
In June, Emirates was fined and barred by China's civil aviation authority from adding new destinations and aircraft in China for six months, following two incidents of unsafe operations.
Russian authorities are investigating a crash involving UAE airline flydubai last year at an airport in the city of Rostov-on-Don, which killed all 62 on board. A preliminary report suggested pilot error may have been the cause. (Additional reporting by Gleb Stolyarov in Moscow; Editing by Alexander Smith)