The Y-12 started as a development of the Harbin Y-11 airframe called Y-11T in 1980. The design featured numerous improvements including a redesigned wing with a new low drag section, a larger fuselage and bonded rather than riveted construction. It also replaced the radial piston engines with turboprops. The prototype was followed by about 30 production Y-12 (I) aircraft before a revised version was produced. This was designated the Y-12 (II), which featured more powerful engines and removal of leading edge slats, first flying on 16 August 1984 and receiving Chinese certification in December of the following year. The power plants are two Pratt & Whitney Canada PT6A-27 turboprops with Hartzell propellers. The Y-12 has a maximum takeoff weight of 5,700 kg (12,600 lb) with seating for 17 passengers and two crew. The aircraft is operated as a light commuter and transport aircraft. The latest development is the Y-12F, which is almost a new design with many improvements: new wings, new landing gear, new fuselage, with more powerful engines from Pratt & Whitney Canada and extended payload and range. The Y-12F made its maiden flight on December 29, 2010, received CAAC type certification on December 10, 2015, and FAA type certification on February 22, 2016. In 2015 Kenmore Air announced that they would begin development of floats for the Y-12 for FAA certification. The Y-12 completed the FAA evaluation flight tests for its automatic flight control system on June 30, 2018, with its performance meeting the requirements, said AVIC Harbin Aircraft Industry Company Ltd (AVIC HAFEI). For details of the 11 variants, click here.