The W-1A was a developed version of the Weick W-1, a homebuilt design intended to fit with the 'safety plane' program of the early 1930s. The original was sold to NACA who, after wind tunnel testing in their Langley facility wind tunnel, contracted for a new version as the W-1A. This new variant replaced the fixed slot forward of the wing used on the original aircraft with large trailing edge flaps. Photo from the National Advisory Committee for Aeronautics.