It is all very concerning, and anyone considering a loan without a back up plan may well find themselves hurting in the future.
What will be interesting to see is if airlines start to go under will others pick up routes/additional a/c and overall capacity remain the same or will there be a reduction in people flying.
AZ for instance are such a backward company, hands tied by unions, have to fly a/c to maintence bases that they do not fly passengers from so flying empty a/c, very old thirsty fleet. I do not think AZ have poor pax loadings on scheduled flights (maybe wrong) just awful management, I know there cargo out of UK has struggled not sure about rest their cargo world. If they went under I am sure that others will expand into the gap they left.
The most flexible, web based buisnesses with lowest overheads will fare the best, older, legacy, union driven companies will be hurting.