The answer is simple. There is overcapacity, but no one is going out of business.
So everyone is losing money.
The free market answer is for the losers be liquidated, sending all the business to those remaining, who will them raise their fares.
"Some analysts have speculated that if Congress doesn't pass meaningful pension funding reform by the fall, Delta will be forced into bankruptcy."
Here's what they are complaining about. They want Congress to pass "meaningful pension reform", which means they want to get out of their pension obligations. There is a landslide of pension defaults starting around the US. Companies in this country want the feds to bail them out while the big boys keep getting theirs. These companies promised their employees pensions when they hired them, now they are trying to weasel out.
Thats not the whole story. This is from the article.
In the memo, Grinstein acknowledged that it may be puzzling to Delta employees that, despite high fuel prices, several other legacy carriers who face the same problem as Delta were able to post modest profits in the second quarter.
There is more than oil and pensions going on here. Otherwise they would all (airlines) be under the gun.