Just as a bit of a correction, the 737-300/400 fleet is down to 112 aircraft, not 140+. I honestly don't see big new orders of Airbus aircraft coming from US Airways for quite a while. Remember that they only "restructured" their existing orders (going from 37 A320-family aircraft and 1 A330-300 to 19 A320-family and 10 A330-200 aircraft) last month. And it seems pretty clear (to me, at least) that those A332's will replace the 767-200ER's, some of which will be hitting 20 years of age in 2007, when the 332's will be entering the fleet. If US Airways planned to be making large purchases of A320-family aircraft in the near future, I doubt they would have restructured that order.
If/when US Airways emerges from bankruptcy on March 31, half of the federal loan guarantee will go to repaying RSA's DIP financing. Now, RSA and GE
will be injecting capital into the company at that time, so their cash position will probably be in the $1.2-1.5 billion range. But they also need to lay out money for regional jet purchases, according to the business plan, so I doubt they'll be buying much else until they achieve good, sustained profitability AND sufficient liquidity to pay down the $1 billion loan.
A lot of people are going to be holding their breath until the company and the pilots manage to come to some agreement regarding the pilots' pensions.