WASHINGTON, May 21 (Reuters) - Major airline CEOs on

Wednesday called on Congress to approve billions of dollars to

modernize the aging U.S. air traffic control system, saying the

current system is "failing Americans."

The heads of American Airlines ( AAL ), United Airlines

, Delta Air Lines ( DAL ), Southwest Airlines ( LUV ),

JetBlue Airways ( JBLU ), Alaska Airlines and Atlas Air, along

with senior executives at FedEx ( FDX ) and UPS in a

joint letter cited recent failures involving Newark Airport and

said the Federal Aviation Administration's technology "is wildly

out of date." They called for urgent action as the busy summer

travel season begins with the Memorial Day holiday this weekend.