A drop in engine oil level is believed to be the preliminary cause of an S7 Airlines emergency landing in Omsk after the crew declared a distress signal over Kazakhstan, infohub.kz reports.
Sources told law enforcement about the possible cause of the incident. The flight was en route from Novosibirsk to Makhachkala and ultimately landed at the alternate airfield in Omsk.
"The preliminary cause is a decrease (drop) in the engine oil level. In such a situation, the crew was obliged to divert to an alternate airfield," TASS quoted the source as saying.
It was reported earlier that the crew of the Novosibirsk–Makhachkala flight declared a distress signal over Kazakhstan. It later emerged that a technical malfunction was the cause.
Russia's Investigative Committee has also opened a probe into the incident. Talgat Lastayev, Vice Minister of Transport of the Republic of Kazakhstan, answered journalists' questions about why the pilots did not land at Kokshetau airport, even though it was closer.