The Yankee was originally designed to minimize the number of airframe parts used, with the aim of simplifying production and saving money. As a result of this philosophy many parts were interchangeable. Due to the use of a non-tapered tubular spar, which doubled as the fuel tank, and the lack of wing washout, the wings could be exchanged left and right. The fin and horizontal stabilizers were interchangeable, as were the rudder and the elevators. The ailerons and flaps were similarly the same part. While it did succeed in making production easier, this design philosophy produced many aerodynamic compromises in the design. For instance, because the flaps were the same part as the ailerons they were too small to be effective as flaps. The lack of wing washout, necessitated by the wing interchangeability requirement, meant that stall strips had to be installed to produce acceptable stall characteristics for certification. Over time this philosophy of compromising the aerodynamics in favour of a minimized parts count was abandoned. For example, the redesign of the AA-1B into the AA-1C by Gulfstream involved wider-span elevators and horizontal stabilizers that produced better longitudinal stability, but were no longer interchangeable with the rudder and fin.