Robert P. Miles, of "The Reader" writes: "Remember the old joke, “How do you become a millionaire?” The punch line is “Start as a billionaire and buy an airline.” That’s what Warren did in 1989, when he invested $358 million into U.S. Air’s preferred stock. It was a short-term mistake, because six years later, in 1995, Warren wrote off most of that investment. U.S. Air had good management, but like textiles, the airline industry was the wrong industry to invest in. This is a very interesting story in that it begs the question of whether NetJets destined to be a shining member of the portfolio, or will it be one of those valuable educational "mistakes?"