more complex and expensive Beechcraft Bonanza. 1974 saw the introduction of the improved B24-R Sierra powered by the Lycoming IO-360-A1B6 engine and new propeller variant as a 1974 model year. The improved C24-R in 1977 was powered by the same engine and larger propeller. Beech also did an aerodynamic cleanup on the "C" model making it 6 knots faster than the "B" model it replaced in 1977 . Sierra production ended at the same time as the Model 23 Sundowner assembly line was closed up, during the aviation economic downturn of 1983. A total of 744 Sierras were delivered. The Musketeer design was further developed into a twin-engined aircraft, the Beechcraft Model 76 Duchess. CT-134 Musketeer The Canadian Forces purchased twenty-four 1971 model B23 Musketeers, with the first CT-134 arriving at CFB Portage la Prairie on March 23, 1971. The initial batch of CT-134s was replaced in late 1981 with twenty-four 1982 model Beechcraft C23 Sundowners, which were designated by the CF as CT-134A Musketeer II. Design Landing gear A significant difference between the Musketeer line and other similar light aircraft is the Musketeer's landing gear. While the competitive Cessna 172s use spring-steel main gear, the Piper PA-28 Cherokees use oleo struts and the Grumman American AA-5s use fiberglass-sprung main gear, the Musketeer family use a trailing idler link gear system with compressed rubber pucks for shock absorption. This gives the aircraft quite different landing characteristics compared to the competition; light touchdowns are often accompanied by the idler links skipping and producing a landing that is less-graceful than anticipated. Nevertheless, with practice, smooth landings are easy to accomplish. As a result of this type of landing gear design, Beechcraft did not design or offer wheel fairings for the fixed gear models. Several aftermarket manufacturers have designed and tested wheel fairings for Musketeers. Operational history During their production years the Musketeer family of aircraft were popular trainers and were used by many flying schools. Most Musketeers are now privately owned. Variants 23 Musketeer Four-seat light cabin aircraft, fixed tricycle landing gear, powered by a Lycoming O-320-D2B piston engine, gross weight of , first certified February 20, 1962. A23 Musketeer II Four-seat light cabin aircraft, fixed tricycle landing gear, powered by a Continental IO-346-A piston engine, gross weight of , first certified June 7, 1963. A23A Four-seat light cabin aircraft, fixed tricycle landing gear, powered by a Continental IO-346-A piston engine, gross