The Curtiss Model 36 XNBS-4 was a 1920s prototype biplane night bomber built by the Curtiss Aeroplane and Motor Company for the United States Army Air Corps.

[1] The XNBS-4 was developed by Curtiss as an improvement on the Martin NBS-1.

Two prototypes, AS68571 and AS68572, were built.

The design did not enter production because it offered no significant improvement over the NBS-1.

[1] Data from National Museum of the United States Air Force[1] and Aerofiles[2]General characteristics Performance Armament