The Cessna 172 Skyhawk is a four-seat, single-engine, high-wing fixed-wing aircraft. First flown in 1955 and still in production, more Cessna 172s have been built than any other aircraft.
Measured by its longevity and popularity, the Cessna 172 is the most successful mass produced light aircraft in history. The first production models were delivered in 1956 and they are still in production. As of 2008, more than 43,000 had been built. The Skyhawk's main competitors have been the Beechcraft Musketeer and Grumman AA-5 series (neither in production), the Piper Cherokee and, more recently, the Diamond DA40.
The Cessna 172 started life as a tricycle landing gear variant of the taildragger Cessna 170. The 172 became an overnight sales success and over 1,400 were built in 1956, its first full year of production. Early 172s were similar in appearance to the 170, with the same straight aft fuselage and tall gear legs, although the 172 had a straight vertical tail while the 170 had a rounded fin and rudder. Later 172 versions incorporated revised landing gear and the sweptback tail which is still in use today. The final aesthetic development in the mid-1960s, was a lowered rear deck that allowed an aft window. Cessna advertised this added rear visibility as "Omni-Vision" . This airframe configuration has remained almost unchanged since then, except for updates in avionics and engines. Production had been halted in the mid-1980s, but was resumed in 1996 with the 160 hp (120 kW) Cessna 172R Skyhawk and was supplemented in 1998 by the 180 hp (135 kW) Cessna 172S Skyhawk SP.
Source: Wikipedia, "Cessna 172", available under the CC-BY-SA License.