Air conditioning and soundproofing also improved passenger comfort in the cabin. Two 500-hp P&W Canada PT6A-6 turboprop engines with three-blade Hartzell propellers gave the King Air a top ceiling of 27,400 feet and a range of 1,565 miles at 270 mph.
Piston-powered aircraft could not match this performance while emerging jet aircraft of the 1960s used turbojet engines that were high-priced, noisy, and had high fuel consumption.
Rather than investing in a completely new and expensive technology, Beech built a vastly improved and marketable business aircraft from its existing production line.
After the King Air's initial success, Beech concentrated on continuous upgrades to appeal to a range of executive and corporate needs.