421A - Two 280kW (374hp) Continental GTSIO-520-D geared, turbocharged and fuel injected flat six piston engines, driving three blade constant speed McCauley propellers.
414A - Two 230kW (310hp) TSIO-520-NBs.
421A - Max speed 444km/h (240kt), max cruising speed 420km/h (227kt), long range cruising speed 364km/h (197kt). Initial rate of climb 1680ft/min. Service ceiling 27,000ft. Range with no reserves and standard fuel 1570km (847nm), with optional fuel 2756km (1488nm).
414A - Max speed 436km/h (235kt), cruising speed 420km/h (227kt), economical cruising speed 340km/h (183kt). Initial rate of climb 1520ft/min. Service ceiling 30,800ft. Range with reserves at economical cruising speed 2460km (1327nm), at max cruising speed 2036km (1100nm).
421A - Empty equipped 2132kg (4700lb), max takeoff 3103kg (6840lb).
414A - Empty 1976kg (4356lb), max takeoff 3062kg (6750lb).
Standard seating for six, optional seating for eight in 421 and 414A, seven in 414.
1901 Model 421s and 1055 Model 414s were built, production of both ceased in 1985.
Pressurised six to eight seat cabin twins
The lineage of the 421 and 414 traces back to the 411, the 421 beginning life as a pressurised development of the 411.
The prototype 421 took to the skies for the first time in October 1965 (three years after the 411). In comparison to the 411 on which it was based, the 421 introduced a cabin pressurisation system, more powerful geared and turbocharged GTSIO-520-D engines and a higher max takeoff weight. Deliveries of production 421s began in May 1967, Cessna at the time claiming it as the cheapest pressurised twin on the market.
First improvements to the 421 were offered with the 421A of 1969, but the 421B Golden Eagle of 1970 featured a number of significant improvements including lengthened nose and wing span, while the engines retained their power to higher altitudes than before. The final expression of the 421 was the 421C available from late 1975, with a bonded wet wing and no tip tanks, higher vertical tail, more efficient props and new trailing link undercarriage.
The 414 was developed as a less powerful, lighter, simpler and lower cost 421. First flown in 1968, it entered production in 1969. It features the wings and fuselage of the 401 and 402 (themselves lighter developments of the 411), plus direct drive, rather than geared engines. The improved 414A Chancellor appeared in 1978, introducing the bonded wet wing without tip tanks. It remained in production until 1985.