The source said William, who is scheduled to join his new helicopter training squad next month at a Shawbury, England, base, will likely face the base's traditional initiation ritual of drinking beer out of a toilet while comrades dump buckets of ice water over his head, The Sun reported Friday.
Meanwhile, Harry, whose training takes place at the Royal Air Force Barkston Heath base, will have to complete the Naked Runway Challenge -- streaking the entire length of the runway -- to earn his "drinking wings."
"No one is forced to take part but I don't know a single person who has chickened out. I'm sure William will be keen to prove he is one of the boys," a Royal Air Force source said. "Harry's test will be different. The runway is long, and freezing at this time of year. It's always a relief when you have passed the initiation and earned your drinking wings."