421C Golden Eagle/Executive Commuter Model with new wing and landing gear. Type approved 28 October 1975, powered by two Continental GTSIO-520-Ls or Continental GTSIO-520-Ns of each, maximum takeoff weight . 859 built. Riley Turbine Rocket 421 Conversion of Cessna 421 aircraft by fitting two Lycoming LTP101 turboprop engines. Formal designation R421BL and R421CL for conversions of 421B and C respectively. Riley Turbine Eagle 421 Conversion of Cessna 421C aircraft by fitting two 750hp Pratt & Whitney Canada PT6A-135 turboprop engines. Formal designation R421CP. Excalibur 421 Re-engined 421C with Pratt & Whitney Canada PT6A-135A or PT6A-112 turboprops, supplemental type certificate held by Excalibur 421 LLC of Paso Robles, California. In 2013 it was announced that Aviation Alliance are acting as program managers for the Excalibur 421 upgrade programme. Advanced Aircraft Regent 1500 Production of the Riley Turbine Eagle 421 conversion by Advanced Aircraft Corporation. Military operators Royal Bahamas Defence Force Bolivian Air Force at least one 421B was in use. Royal Cambodian Air Force Ivory Coast Air Force Royal New Zealand Air Force three 421C. No. 42 Squadron RNZAF Pakistan Army Aviation at least one 421 in use. Turkish Army Aviation at least three 421Bs in use. Air Force of Zimbabwe at least one 421A in use. Specifications (C 421C) See also Notes References Bibliography External links 421 1960s United States civil utility aircraft Low-wing aircraft Aircraft first flown in 1965 Twin piston-engined tractor aircraft