Ok, for the sake of argument, let's assume UA files for Chapter 11.
Let's also assume (again, for the sake of argument) that after languishing in the throes of Chapter 11 bankruptcy for a year, they're unable to get things turned around and begin Chapter 7 liquidation proceedings.
So now there's a gaping hole at DEN, ORD, IAD, SFO, and LAX. Also, a huge player in the Pacific is totally gone. What happens next?
Assuming cash balances of the other carriers remain as they are now, look for the following to occur:
1. F9 grabs up all the spare planes it can for a focused expansion at DEN. CO recalls every one of their planes from MHV and opens a small hub at DEN, with both carriers eventually having combined operations there equalling the size of UA's current DEN hub. AS does not try for a hub at DEN, but calls it a "focus city" and triples their flight operations there within a year of UA ceasing operations.
2. DL (just about the only carrier with big-time cash on hand) snatches up all of UA's Pacific ops, but do not use SFO or LAX for domestic hub operations.
3. AA expands at ORD, at the expense of traffic growth at STL. STL remains essentially flat for at least three years while AA focuses on getting a stranglehold on ORD, then sees small year-over-year growth.
4. B6 begins service to LAX, but within 2 years finds they've painted themselves into a corner, being stuck as a low-cost carrier serving transcontinental nonstops only (LGB/LAX-JFK, IAD, FLL, etc). They perform well, but do not flourish into the juggernaut the media has predicted they would become. UA's traffic at LAX is nearly evenly divided between AA, AS, DL, HP, and CO.
5. IAD sees their traffic drop off dramatically and is not chosen as a hubsite by anyone, since there is no clear-cut reason for other carriers to hub there (US has also ceased operations by this time, freeing up CLT, PHL, and PIT).
6. NW and AS pick up the slack at SFO, with AS continuing to focus on service up and down the West Coast, with a few transcons from SFO.
7. A MAJOR bidding war ensues for UA's coveted LHR operations. DL, NW, and CO go head-to-head for these slots, but DL sees more value in UA's Pacific ops, letting CO and NW battle it out. Eventually NW wins, but overpays in retrospect, because a U.S./E.U. Open Skies agreement is hammered out within two years, allowing all major U.S. carriers access to LHR.
These are just predictions, and again, they're based on the VERY unlikely scenario that UA disappears entirely. The odds are UA will enter Chapter 11 before Christmas 2002, emerging from bankruptcy protection a year later.
"In this present crisis, government is not the solution to our problem - government IS the problem." - Ronald Reagan
Comments made here are my own and are not intended to represent the official position of Alaska Air Group