Three Curtiss Challenger-engined Curtiss Thrush prototypes (serialled G-1 to G-3) were built at Curtiss' Garden City factory, but these were underpowered[REF] and production examples, redesignated Thrush J (serialled 1001 to 1010) with Wright Whirlwind engines, were built at the Curtiss-Robertson St Louis factory.
The fuselage was built up as a Pratt truss frame formed mainly from Duraluminum tubing and fittings with welded Chrome-moly tubing reinforcing highly stressed areas and covered in fabric [REF].