Aeropesca Colombia Flight 221 Aeropesca Colombia Flight 221 Aeropesca Colombia Flight 221 was an internal scheduled passenger flight from Florencia Airport to Neiva Airport in Colombia. On 26 August 1981 it was being operated by a Vickers Viscount turboprop airliner registered in Colombia as "HK-1320" when it collided with Mount Santa Elana, an Andean mountain peak, destroying the aircraft and killing all 50 on board. The investigation by the Colombian authorities concluded the probable cause was "continuing VFR in meteorological conditions below the minimum laid down in the Manual of Colombian air routes". The aircraft was a four-engined Vickers Viscount 745D turboprop airliner registered
Turboprop jet cruising speeds for most missions. The Bear would serve as their most successful long-range combat and surveillance aircraft and symbol of Soviet power projection throughout the end of the 20th century. The USA would incorporate contra-rotating turboprop engines, such as the ill-fated twin-turbine Allison T40 — essentially a twinned up pair of Allison T38 turboprop engines driving contra-rotating propellers — into a series of experimental aircraft during the 1950s, with aircraft powered with the T40, like the Convair R3Y Tradewind flying boat never entering U.S. Navy service. The first American turboprop engine was the General Electric XT31, first used