About the King Air F90
The evolution that led to the King Air F90 began with the Model C90 which was introduced in 1971. The C90 featured an increased wingspan over the B90 by 4 ft 11 in to 50 ft 3 in. Maximum Take-off weight was increased to 350 lb to 9,650 lb and upgraded with PT6A-20A engines. During this time the Model E90 was also introduced, broadly similar outside having PT6A-28 engines. Further refinements of the series would produce the Model F90 and follow-on Model F90-1.
The F-models took the Model 200 King Air T-tail and combined it with the fuselage and wings of the E90. The engine used was the PT6A-135 of 750 shp (560 kW) driving four-bladed propellers. On January 16th, 1978, The F90 prototype flew for the first time. 203 production versions would follow between 1979 and 1983, with the F90-1 superseding the F90 that year.
The F90-1 was built with redesigned engine cowlings, upgraded PT6A-135A engines, hydraulic landing gear, and triple-fed electrical bus. Only 33 were built by the time production on the model was terminated in 1985.