Cessna 411 was the first entry of the company into the eight-seat cabin class twin market, which was dominated by Beech Queen Air at that time.

The Cessna 411 prototype first flew in July of 1962. It has a Continental Motors GTSIO-520-C 340 hp (254kW) engine. The 411 actually started as a new design of the 410 concept.

In 1965, Cessna developed two similar type of aircraft but with a much lower cost. These were models 401 and 402. They were much lighter, less powerful and had direct drive engines.

The 401 and 402 models have turbocharged Continental engines (300 hp 225kW) and three-bladed, constant speed, fully feathering propellers.

The 401 model was essentially used for corporate transport and had fewer seats. 402 model, on the other hand, was mostly used for commuter and freighter work.

The airframe of these models had a similar appearance as that of the pressurized Cessna 340, having the same four small oval windows.

Different variants of these models were made with minor refinements. For example, model 402A is relatively the same except for lengthened, square windows and a crew entry doorway. It also had a baggage compartment. It was certified in January 1969.

Another variant of the model 402 is model 402B. Model 402B was marketed either as a Utiliner or Businessliner. It was certified in November 1969. The Utiliner variant had a ten-seat configuration intended for commute airline operations. The Businessliner variant had a six to eight seat configuration intended for corporate transport.

The 402C variant was certification September 1978. This particular model can be categorized either a Utiliner or Businessliner. It had an increase take-off weight, larger wingspan with new landing gear.

General Characteristics

Capacity
Model 411
Crew: Two
Passengers: Four to Six

Model 402C
Crew: One to Two
Passengers: Up to 9

Powerplant
Model 411
2x Continental GTSIO-520 flat-six turbocharged piston, 340hp (254 kW) each
Model 402C
2x Continental TSIO-520-VB turbocharged, fuel-injected piston engines, 325hp (240 kW) each

Performance
Model 411
Maximum Speed: 431 km/h
Cruise Speed: 360 km/h
Stall Speed: 135 km/h (flaps down)
Range: 2,090 km
Rate of Climb: 1,600 ft/min
Model 402C
Maximum Speed: 428 km/h
Cruise Speed: 394 km/h
Stall Speed: 132 km/h
Range: 2,360 km
Rate of Climb: 1,450 ft/min

Dimensions:
Model 411
Length: 33 ft 5 ½ in
Height: 11 ft 6 ½ in
Wing area: 200 sq ft
Wingspan: 39 ft 10 ¼ in
Model 402 C
Length: 36 ft 5 in
Height: 11 ft 6 in
Wing area: 225.8 sq ft
Wingspan: 44 ft 2 in

Weights
Model 411
Empty Weight: 3,829 lb
Maximum take-off Weight: 6,500 lb
Model 402C
Empty Weight: 4,069 lb
Maximum take-off Weight: 6,850 lb

Sources:
http://www.wikipedia.org/wiki/cessna_402
http://www.wikipedia.org/wiki/cessna_411
http://www.airliners.net