which prevented their participation in the scheduled event, so they stayed in the United States. Investigation The police quickly surrounded the site and removed any spectators; recovery of airplane pieces started soon afterwards. Both the cockpit voice recorder and flight data recorder were found quickly; unfortunately, the recording suddenly stopped nine seconds after the last transmission, 26 seconds before the crash. While recovering the engines, the number-two (inner left) engine was found to be cut in half, held together only by the fuel lines. When the engine was further examined, the disc of the low-pressure turbine was found to be missing; despite an extensive search, it was not found at the crash site. Finally, the turbine disc was found about from the site; it was broken into three similar-sized pieces. After recovering the cockpit, the throttles of both engines 2 and 3 (inner right) were found to be shut off, while on engine 4 (outer right) the thrust was set to maximum. The investigating commission asked the Soviets if an Il-62 was able to reach the runway with one engine operating; no conclusive answer was received, but calculations based on the official technical data suggested that, while one engine thrust was insufficient for the aircraft to maintain altitude, it was enough to reach the runway and try to land. No explanation was found why the aircraft with one engine operating at maximum power suddenly entered a steep dive. Detailed analysis of the pieces of the turbine disc found several metallic impurities on the edges of two of them; in one case, they were identified as coming from the engine nacelle, in another, the impurities came from the nacelle, the hull, control actuators and finally, electrical cables. Also, detailed examination of the surface of the broken disc showed significant evidence of fatigue cracking. Sequence of events Finally, when the control pushers were found to be cut in half, it was proven that the cut was not caused by the crash, and some traces of the metal alloy the turbine disc was made of were found on the surface of the cut, the sequence of events became clear. The disaster started when Mikołaj Kopernik was instructed to climb to a higher flight level. When the necessary thrust was applied to all four engines, the low-pressure turbine of the number 2 engine disintegrated after 9 seconds. One piece of the turbine disc got