US Airways will defer delivery of 54 Airbus aircraft as part of a new “liquidity improvement program,” the airline announced today.

Under the new plan, US Airways plans to take the 54 Airbus airplanes, previously scheduled for delivery between 2010 and 2012, “in 2013 and beyond.” In addition, said the airline, it will delay launch of Airbus A350XWB operations from 2015 until 2017.

Specifically, it will take two A320-family jets and two A330s next year, rather than 18 and seven, respectively. In 2011, it now plans to take 12 rather than 30 A320s and no A330s instead of three; in 2012, it again expects to take 12 A320s rather than the previously scheduled 24. The new A320 schedule shows 16 deliveries in 2013, 18 in 2014 and 12 in 2015, while the A330 ledger shows no deliveries in 2012, five in 2013 and three in 2014.

The airline estimates that the deferrals will cut its capital expenditures over the next three years by approximately $2.5 billion and reduce near- and medium-term obligations to Airbus and others by approximately $132 million. However, the deferrals will not “significantly” alter the airline’s capacity plans because it will keep aircraft originally scheduled to be replaced until the rescheduled new aircraft delivery dates.

“Although we will slow deliveries during the next three years, over that period we will continue to modernize our fleet, which is already one of the youngest in the United States,” said US Airways executive vice president and CFO Derek Kerr. “We have financing commitments for all 28 aircraft [scheduled for delivery in 2011 and 2012] and believe this is a more manageable delivery rate given the current economic environment.”