sentences:  After the December 2012 Red Wings Flight 9268 crash in Vnukovo, Russian aviation authorities initiated an emergency check of airline operational activities and fleet maintenance, resulting in the revocation of the carrier's AOC effective on 4 February 2013.The airline had ceased all operations the day before and owner Alexander Lebedev announced that no return to operation was planned.On 4 April 2013, NRC sold Red Wings Airlines Group "Guta" for a symbolic one ruble (in this case, leased aircraft remained with the lessor NRC-owned company "Ilyushin Finance").