The King Air began life as a turboprop development of the Queen Air designed to meet a US Army requirement for a staff/utility transport. A prototype PT6 powered Queen Air Model 65-80 (later 65-90T) began test flying in 1963 and the type was subsequently ordered by the US Army in unpressurised form as the U-21A. The King Air 100 series was announced in May 1969. Compared with the 90 series it was 1.27m (4ft 2in) longer, allowing greater seating capacity, and featured a reduced wing span and larger rudder.