While no company celebrates billions of dollars resting on its balance sheet, Delta has whittled down its adjusted net debt by $2.5 billion from $17 billion at year-end 2009 to $14.5 billion at 31 March. "We must continue to de-lever the balance sheet and de-risk the business," stresses Anderson. "We will remain disciplined with costs and capital commitments." Days of airline CEOs being "smitten by market share", are over says Swelbar. United Continental chief executive Jeff Smisek admits, while the merged network and financial flexibility allows for a strong foundation to build sustained profitability, "In this volatile environmentevery new route requires an even stronger business case." One of the most prominent indicators of a new kind of airline business discipline being practiced by US carriers is sustained capacity constraint. US carriers turned round a net loss of just under $3 billion in 2009 to a net profit in excess of $3 billion last year.