It really all depends on whose ticket stock the ticket was issued, since that is which company is control of the "funds" (mileage or actual hard money) for those flights.
So assume you're flying on LH
, but your ticket was issued on US Airways' 037 ticket stock. US controls the "money" backing up the ticket, and once LH
picks up your flight coupon they would then bill US for the face value of it - or in your case, whatever value they've agreed to bill each other at for mileage travelers.
But if US goes under, the other carriers know that tickets held under 037 stock becomes worthless - because if they take it for carriage and then attempt to bill US, they won't get paid.
Now in the event you're traveling domestically, federal law enacted after 9/11 and recently extended allows you to travel STANDBY ONLY on healthy competing U.S. carriers who fly the same route for a fee not to exceed $25.00 each way per person. But again, it's standby only, and as far as I've seen it's for domestic travel only.
Since your ticket was using US miles, odds are your ticket number starts with 037 - meaning it's on their stock. Should they go under for any reason, you'll likely have no recourse whatsoever.
"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