The 24-year-old prince has already completed five months of his two-year course to become an Army Air Corps combat pilot. The Sun quoted Harry as saying, " The flying is fantastic. But there are times I've thought, I'm really not cut out for this mentally. It's really intense."
He added: "I knew it was going to be tough, but never thought it would be this tough. I hope I've got the physical skills to fly a helicopter. But there are the exams and everything. I can't do maths. I gave that up when I left school."
Harry gave the interview after playing in a charity polo match at the end of a two-day trip to New York, his first official visit overseas.