A funny thing happened to an older generation of Boeing Co. 747 jumbo jets on their way to dusty oblivion in desert parking lots. Instead of being scrapped, the humpbacked planes are back in demand as workhorses of global shipping. Booming trade is stoking the need for big, long-range jets to haul time-sensitive goods, from Apple Inc. iPhones made in China to fresh flowers grown in Latin America. Interest in Boeing’s 747-400 freighter family was already rebounding last year, even as Delta Air Lines Inc. and United Continental Holdings Inc. hosted nostalgic farewell tours to mark the end of U.S. passenger service on the four-engine behemoth nicknamed the “Queen of the Skies.” With Boeing’s factory-fresh models sold out through 2021, cargo carriers are snapping up jumbo freighters that were built from 1993 to 2009 — if they can find them. “It’s tightened up, that’s for sure,” said William Flynn, chief executive officer of Atlas Air Worldwide Holdings Inc., the world’s largest operator of jumbo freighters. The lessor is in the process of adding six 747-400 freighters to its fleet. “There’s just a finite number of aircraft,” he said. Demand is strongest for used 747s originally built as freighters, since they have hinged noses that flip open to load oversize cargo such as oil-drilling equipment. Lease rates have rebounded for the aircraft, while the number of stored models has shrunk to the point where almost every airworthy plane is spoken for, according to George Dimitroff, head of valuations for Flight Ascend Consultancy. (Bloomberg)