Before the race started, many of the aircraft had mechanical issues during test flights and while traveling to San Francisco to meet the final qualification deadline. "Pabco Flyer" (Irving) broke a fuel line while conducting a test flight on August 5 from San Francisco to San Diego, and was forced down in a cow pasture near Point Sur, approximately south of Monterey.  "Golden Eagle" (Frost/Scott) hit a gopher hole on the runway while taking off from San Diego and wrecked the landing gear and propeller. "City of Peoria" (Parkhurst/Lowes) was delayed by sandflies, and "Bluebird" (Giles) was stuck at Detroit with engine issues. 