In his annual letter to Berkshire Hathaway shareholders released Friday, investment mogul Warren Buffett said the company’s flight-services division–which includes fractional provider NetJets and aviation training company FlightSafety International–set a record last year with pre-tax earnings increasing 49 percent to $547 million. “Corporate aviation had an extraordinary year worldwide, and both of our companies–as runaway leaders in their fields–fully participated,” he wrote. At FlightSafety, revenues climbed 14 percent and pre-tax earnings soared by 20 percent. Buffett estimates that FlightSafety trains about 58 percent of U.S. corporate pilots. NetJets, which Buffett regards as the “unchallenged leader” in the fractional industry, now operates 487 jets in the U.S. and 135 in Europe, “a fleet more than twice the size of that operated by our three major competitors combined.” NetJets Europe, which ran cumulative losses of $212 million in its first 10 years of operation, now has “real momentum,” Buffett says, with earnings tripling there last year. The U.S. operation is also doing well financially, he notes, due to “increasing customer demand.”