The stock market crash of 1929 and the Great Depression threatened the continued existence the American aviation industry just as it started to grow in the wake of unprecedented government legislation and Lindbergh's transatlantic flight. The newly-formed Hamilton Standard Propeller Corporation, suffering from dwindling government contracts, scrambled for a new product to sustain the young corporation. Chief engineer Frank Caldwell's design for a hydraulic two-position, controllable-pitch, or hydro-controllable, propeller that he had patented in 1929 saved the company.
In 1933 Hamilton Standard and Frank Caldwell won the prestigious Collier Trophy for development of the company's controllable pitch propeller. This is a chromed cutaway of that type of propeller on its crankcase.