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 in the experimental Consolidated Vultee XP-81. The XP-81 first flew in December 1945, the first aircraft to use a combination of turboprop and turbojet power. The technology of the Allison's earlier T38 design evolved into the Allison T56, with quartets of the T56s being used to power the Lockheed Electra airliner, its military maritime patrol derivative the P-3 Orion, and the widely produced C-130 Hercules military transport aircraft. One of the most produced turboprop engines used in civil aviation is the Pratt & Whitney Canada PT6 engine. The first turbine-powered, shaft-driven helicopter was the Kaman K-225, a development of Charles