The CAB-1, officially named "Coach" was a late 1929 try at a more acceptable five-seat cabin biplane. It bore little resemblance to it's predecessors and was a sesquiplane, meaning that the smaller lower wing had less than half the area of the upper.

The novel feature of the CAB-1 resulted from trying to improve the passengers headroom by using the space between the top of the fuselage and the upper wing as added cabin area. Another change was to put the pilot inside at the front of the five-place cabin.

The powerplant was the 300 hp Wright J-6-9. The landing gear was the outrigger type of earlier Stearmans and ran the shock absorber strut directly to the upper longeron. Stearman did not carry testing of the CAB-1 to certification. The airplane with experimental license X8808 was dismantled.