I think that if passenger numbers go down and fixed costs stay the same, and if passengers aren't very price sensitive (their company is paying their fare) then

I think that if passenger numbers go down and fixed costs stay the same, and if passengers aren't very price sensitive (their company is paying their fare) then it makes sense to raise prices. The trouble is that this will drive out the holiday flyers and leave them dependent on business flyers whose companies can turn off the tap on a whim. And will have every incentive, and excuse, to do so.