The Beechcraft King Air series has its roots in the Twin Bonanza of 1951. That model of Beechcraft was enlarged and re-engined to become the model 65 Queen Air. The Queen Air design changed with a swept tail and pressurization. With the addition of Pratt & Whitney turboprop engines, the Queen Air became the Beechcraft model 90 King Air. The Beechcraft King Air 90 begat the stretched Beechcraft King Air 100, which in turn had a T-Tail added to become the Beechcraft King Air 200. Increased gross weights and more powerful PT6A-60A engines made the Beechcraft King Air 200 into a Beechcraft King Air 300. A stretch to the fuselage added more room and the Beechcraft 300 became the Beechcraft King Air 350.
The Beechcraft 350's roomy cabin seats eight and has an aft-lavatory. The cabin is not round, but shaped similar to a loaf of bread. This gives the passenger more shoulder room over a round cabin. While the Beechcraft King Air 300 never outsold the Beechcraft B200, the Beechcraft 350 offers enough extra room, payload and power to make it an attractive step up from the Beechcraft B200. Certified in 1989, the Beechcraft King Air 350 continues in production to this day. A cargo door is also available on the Beechcraft King Air 350.