a single demonstration Model 23-24 was equipped with a constant speed propeller. In succeeding years approximately one third of production aircraft were delivered with the constant speed propeller. The Super Musketeer typically has a useful load of 1050 to 1080 pounds – giving it one of the highest payloads of four-cylinder, fixed gear, simple single-engined aircraft available. Most Model 23-24s were produced in a four-seat configuration. A very small number were produced with a 4+2 configuration with the baggage area convertible to seat two children. This configuration option was more common on the Sierra models that followed the Model 23-24. One of the few weaknesses of the Model 23-24 was that it had a simple heat distribution system that provided warm air via the firewall to the area under the instrument panel only. This meant heat to the rear seat passengers was less than optimal. Later aircraft featured increasingly better ducting designs that provided heat to all four seating positions. The fixed-gear Model 23-24 was produced only between 1966 and 1969. A total of 369 Musketeer Super IIIs were completed before it was superseded by the Model 24 Sierra. These were serial numbered MA-1 to MA-369 and were the only models to have a "MA" serial number, making them easier to distinguish than other members of the Musketeer line. In the last few airframes of the series a new instrument panel with the same "vertical tape" gauges that were used in the early Sierras was introduced. These models were known as the A24 and are not to be confused with the first Sierras, which were designated A24R models. Other than the instrument panel these aircraft were mechanically identical to the earlier A23-24 model. Model 24 Sierra The Model 23-24 Musketeer Super III proved the utility of the engine in the Musketeer airframe, but the fixed-gear configuration prevented using full advantage of the extra power of the injected Lycoming. The obvious solution was retracting the landing gear and this resulted in the Model 24R. The Musketeer Super R, A24R in 1970 was the first model year for the new retractable version of the Musketeer to compete with the Piper Arrow. Renamed the "Sierra", in 1972. The initial A24-R Sierra was powered by a Lycoming IO-360-A1B of and sold for a standard price of $24,950. The Model 24R completed the Beech line between the fixed gear Musketeers and the much larger, faster,