The early success of the original Citation led Cessna to develop a larger capacity Citation model in the mid 1970s. stretched Citation in September 1976.
The fuselage was extended by 1.14m to increase maximum seating capacity, while more powerful Pratt & Whitney Canada JT15D4 engines and greater fuel tankage meant higher cruise speeds and longer range. Increased baggage capacity and increased span wings were also added.
The new Model 550 Citation II first flew on January 31 1977 and FAA certification for two pilot operation was awarded in March 1978.