Austrian Airlines Flight 901 Austrian Airlines Flight 901 Austrian Airlines Flight 901 was a flight from Vienna, Austria to Moscow, USSR (now Russia) via Warsaw, Poland. On the night of 26 September 1960 the aircraft operating the flight, a Vickers Viscount, crashed near Moscow while on its approach to land, killing 31 of the 37 passengers and crew on board. The aircraft was a Vickers Viscount 837 four-engined turboprop airliner registered "OE-LAF". The aircraft had first flown on 10 February 1960 and had been delivered new to Austrian Airlines about two weeks later, seven months before the crash. The aircraft departed Warsaw with six
Turboprop Kaman's K-125 synchropter, which used a Boeing T50 turboshaft engine to power it on 11 December 1951. Compared to turbofans, turboprops are most efficient at flight speeds below 725 km/h (450 mph; 390 knots) because the jet velocity of the propeller (and exhaust) is relatively low. Modern turboprop airliners operate at nearly the same speed as small regional jet airliners but burn two-thirds of the fuel per passenger. However, compared to a turbojet (which can fly at high altitude for enhanced speed and fuel efficiency) a propeller aircraft has a lower ceiling. The most common application of turboprop engines in