Born in Oregon, Diteman moved to Billings in the 1920s with his wife and two young sons, and took up cattle ranching. He soon developed a fascination with flying, and earned a pilot's license in August 1929. Armed with only 70 hours of flying experience, he traveled to Kansas City, purchased a used, open-cockpit monoplane, and flew east on his great adventure.
Diteman claimed to be a descendent of Sir Frances Drake, and he named his new airplane the Golden Hind, after Drake's famous ship. By October, Diteman had flown the Golden Hind to Harbour Grace, Newfoundland, ostensibly to research his family's historical connection to Drake. He spent three days there before taking off again. It was assumed he was returning to Montana, but then a friend in Harbour Grace found a sealed note that Diteman had left for him:
"I am bound for London. You will find a package and two letters in my hotel room. Forward same as addressed. Be sure to wrap the bundle in heavy paper. Hold the tools a few days for cable instructions otherwise send to same address. I have 165 United States standard gallons of gasoline, at a conservative estimate enough for 25 hours.
"Many thanks, you Newfoundlanders, for your kindness, and apologies for my impromptu lies about Drake. He did not bring me here, nor to London, albeit I am his descendant. You will hear from me."
That morning, observers along the Newfoundland coast watched Diteman's little plane flying eastward into the mist. Had he succeeded, he would have been the second person to fly across the Atlantic alone ... but he was never seen again.