This is the moment Russian Air Force crews perform a mid-air refueling operation with fighter jets. The footage was shared online by the Russian Ministry of Defence, who said: "The crews of the MiG-31BM, Su-34 and Su-24MR aircraft of the Central Military District performed more than 200 air refueling during an exercise in the Chelyabinsk region. The pilots worked out double and single refueling day and night at an altitude of 4,000 to 7,000 meters (13,000 to 23,000 feet) and at a speed of over 600 kph (370 mph), approaching the tanker at a distance of up to 10 meters (33 feet).