The Aerostar emerged as a
mid-wing cantilever
monoplane powered by two wing-mounted
piston engines, with
retractable landing gear in a
tricycle configuration. It is designed to seat six, and is distinguished from light twins of similar size and weight by its high
wing loading, careful attention to fine aerodynamic details, a
mid wing, and in early models, the absence of
cowl flaps; Smith was adamant that they were not needed because of the refined cooling system design. Despite this, the later 700P used cowl flaps because engine cooling of earlier models proved marginal if the system is not maintained rigorously. The engines of early 601s are turbonormalized—they retain the higher
compression ratio typical of a non-turbocharged engine, and the turbo system is designed to primarily to compensate for increasing altitude by providing more boost pressure as the outside air pressure declines. Later models featured a redesigned turbo system intended to increase reliability and be more forgiving of improper operation by the pilot. Unusual Aerostar design features include electrically operated remote fuel valves, which avert the need to run fuel lines into the cockpit; electro-hydraulic nosewheel steering; a
flight control system that relies on push-pull rods and torque tubes rather than cables; and unusually thick and stiff wing skins, which—together with the high wing loading—give the Aerostar an unusually smooth ride in
turbulence. Some disadvantages of the aircraft compared to its competitors are the absence of a nose baggage locker, and a cabin that can only be accessed through a single clamshell door next to the pilot's seat; aircraft occupants other than the
pilot in command must climb over the folded pilot's seat to access their seats. Aerostar model numbers nominally refer to the total installed engine horsepower, but some model numbers vary from the precise total, particularly the later models. ==Operational history==