China National Aviation Corporation
During his naval career, Westervelt was also involved in naval aviation. Westervelt became friends with Boeing and worked with him on seaplanes, co-designing the Boeing Model 1, and co-founded what would become The Boeing Company. He left Pacific Aero Products after 1916 after being transferred to the east coast by the USN. Westervelt was assigned by the Navy Bureau of Construction and Repair to work with Curtiss Aeroplane and Motor Company on the Curtiss NC float plane and later became vice-president with Curtiss-Wright following his retirement from the USN. From 1930 to 1931 Westervelt went to China to help out with the China National Aviation Corporation.