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
Three-surface aircraft canard foreplanes flew in 1985 and derivatives of this design became the only military types to enter production. Also in 1979, Piaggio began design studies on a three-surface civil twin turboprop which, in collaboration with Learjet, would emerge as the Piaggio P.180 Avanti. This type first flew in 1986 and entered service in 1990, with production continuing today. In the Avanti, the three-surface configuration is claimed to significantly reduce wing size, weight and drag compared to the conventional equivalent. Two experimental aircraft adopting this configuration were subsequently built by Scaled Composites under the lead of Burt Rutan and flown in