Aeroflot Flight 593 was a Moscow–Hong Kong passenger service operated by Aeroflot – Russian International Airlines, flown with an Airbus A310-300, that crashed into a hillside of the Kuznetsk Alatau mountain range, Kemerovo Oblast, Russia, on 23 March 1994. All 63 passengers and 12 crew members perished in the accident. No evidence of technical malfunction was found. Cockpit voice and flight data recorders revealed the presence of the pilot's 12-year-old daughter and 16-year-old son on the flight deck. The son had unknowingly disengaged the A310 autopilot's control over the aircraft's ailerons while seated at the controls. The aircraft rolled into a steep bank and near-vertical dive. Despite managing to level the aircraft off, the pilot over-corrected the attempt to pull up, causing the plane to stall and then crash into a hillside. The aircraft involved in the accident was a leased Airbus A310-304, registration F-OGQS, serial number 596, that was delivered new to Aeroflot on 11 December 1992. Powered with two General Electric CF6-80C2A2 engines, the airframe had its maiden flight as F-WWCS on 11 September 1991, and was one of five operating for Russian Airlines, an autonomous division of Aeroflot – Russian International Airlines that was set up for serving routes to the Russian Far East and Southeast Asia. On average, the crew of three operating the aircraft had logged 900 hours on the type. The jet was en route from Sheremetyevo International Airport to Hong Kong Kai Tak International Airport with 75 occupants aboard, of whom 63 were passengers. Most of the passengers were businessmen from Hong Kong and Taiwan who were looking for economic opportunities in Russia. The relief pilot, Yaroslav Kudrinsky (Russian: Ярослав Кудринский), was taking his two children on their first international flight, and they were brought to the cockpit while he was on duty. Aeroflot allowed families of pilots to travel at a discounted rate once a year. Five people were in the cockpit: Kudrinsky, copilot Igor Piskaryov (Russian: Игорь Пискарёв), Kudrinsky's son Eldar (Russian: Эльдар Кудринский), his daughter Yana (Russian: Яна Кудринская), and another pilot, Vladimir Makarov, who was flying as a passenger. With the autopilot active, Kudrinsky, against regulations, let the children sit at the controls. First his daughter Yana took the pilot's left front seat. Kudrinsky adjusted the autopilot's heading to give her the impression that she was turning the plane, though she actually had no control of the aircraft. Shortly thereafter Eldar occupied the pilot's seat. Unlike his sister, Eldar applied enough force to the control column to contradict the autopilot for 30 seconds. This caused the flight computer to switch the plane's ailerons to manual control while maintaining control over the other flight systems. A silent indicator light came on to alert the pilots to this partial disengagement. The pilots, who had previously flown Russian-designed planes which had audible warning signals, apparently failed to notice it. The first to notice a problem was Eldar, who observed that the plane was banking right. Shortly after, the flight path indicator changed to show the new flight path of the aircraft as it turned. Since the turn was continuous, the resulting predicted flight path drawn on screen was a 180-degree turn. This indication is similar to the indications shown when in a holding pattern, where a 180-degree turn is intentional to remain in one place. This confused the pilots for nine seconds. During this confusion, the plane banked past a 45-degree angle to almost 90 degrees (steeper than it was designed for). The A310 cannot turn this steeply while maintaining height, and the plane started to lose altitude quickly. The increased g-forces on the pilots and crew made it extremely difficult for them to regain control. The autopilot (which no longer controlled the ailerons) used its other controls in a bid to compensate, pitching the nose up and increasing thrust. The plane began to stall. The autopilot, unable to cope, disengaged and its display went blank. To recover from the stall, an automatic system lowered the nose and put the plane into a nosedive. The reduced g-forces enabled the captain to re-take his seat. The co-pilot then managed to pull out of the dive, but over-corrected, putting the plane in an almost vertical ascent, again stalling the plane, which fell out of the sky into a corkscrew dive. Though the captain and the co-pilot regained control and leveled out the wings, their altitude by then was too low to recover, and the plane crashed at high vertical speed, estimated at 70 m/s (160 mph).