In Biggles Makes a Bet, Colonel Dawson was a staff security officer with the United States Air Force in Britain. Air Commodore Raymond called him to Scotland Yard to tell him about an illegal air shuttle racket which Biggles and Marcel Brissac had uncovered where fake dollar bills were being flown to France and cigarettes spiked with marijuana were being flown into Britain on the return journey. As the importer of the cigarettes, a man named Caulder, was an American and believed to be operating near American airbases, it was believed that his customers were American servicemen. Raymond asked Dawson if he had noticed any unusual behaviour among American aircrews.
Dawson confirmed that there was indeed a spate of unexplained low flying and stunting which had led to a series of air crashes. In his view, access to marijuana, which was known to eliminate fear. might well be the answer.