The crisis in Airbus' widebody aircraft program has big implications for the world's two principal planemakers and for a handful of international carriers, but U.S. airline operators are offering a collective shrug.Airbus said last week that its A380 deliveries would be delayed for a second time, raising fears about customer commitment to the controversial long-range plane that's capable of seating more than 500 passengers. Investors fled the shares of European Aeronautic Defence & Space Co., which owns 80% of Airbus, and bid up the stock of competitor Boeing ( BA). For Airbus, the timing regarding the A380 delay was made worse by the fact that it comes as the company is also redesigning its proposed new A350 amid far greater enthusiasm for Boeing's planned 787. To consultant Scott Hamilton, who publishes an online newsletter about Airbus and Boeing, it's no surprise that U.S. passenger carriers haven't ordered the A380 or for that matter raised any particular concerns. "The A380 is not a North American airplane," Hamilton said. "It's for Asia and the Middle East." Though it's conceivable that Northwest Airlines ( NWACQ) or UAL ( UAUA), the major U.S. carriers to Asia, could one day place orders, he said, the primary customers are international airlines like Emirates, Singapore Air, Malaysia Airlines and Qantas. US Airways ( LCC) is the only U.S. customer for the A350, while FedEx ( FDX) and UPS ( UPS) are the only U.S. airline operators with orders for the A380. And, of course, the latter two don't carry passengers.