If your reason for not being able to fly is serious enough -- say, a death in the family -- try contacting your airline to see if you can work something out, but do not count on this. But sometimes the equivalent of a doctor's excuse plus a human being on the phone or at the airline desk might get you a refund in some cases. At least with Southwest, you don't have that pesky change fee but hang on to your ticket number because you'll have to fly them within the next 12 months.
Q. My flight was cancelled because of bad weather. How much will the airline give me for a hotel and food?
A. I get so many questions about this, and I'm sorry to say the airlines are not obligated to give you anything in the way of meals or lodging because bad weather is considered a force majeure (greater force) event.
Look in your airline's contract of carriage and you'll see that force majeure actually covers a whole bunch of possibilities. On American's website, for example, it includes "meteorological conditions, acts of God, riots, civil commotion, embargoes, wars, labor disputes."
It also mentions, "any fact not reasonably foreseen, anticipated or predicted by American." Now that's what I call an all-inclusive clause.
You might remember the big brouhaha for fliers in Europe during the Icelandic volcanic eruptions; many European airlines caved and put up folks whose flights were stranded but that was an unusual case and in the United States, yes, you are pretty much on your own when mother nature calls (or roars).
Q. I'm going to Europe. I'll fly to New York on one airline, then take another airline to London. I left a two-hour window at JFK to make my Heathrow flight. I'll be OK, right?
A. I recently got a very sad letter from a flier involved in a similar scenario, except she was taking a whole series of interconnecting flights from London, and because her initial flight to New York was late, the whole itinerary fell apart like a house of cards.
The main point to remember is leaving yourself just two hours to make an international flight might not be enough. You cannot predict delays, whether it's weather or mechanical problems.
Also, airline-mandated arrival times for flights vary. Delta says passengers flying to international destinations must get to the airport three hours ahead of time, and if you're not checked-in at least 60 minutes before departure - with or without baggage - you might not be allowed on the plane. And that'll cost you an "international change fee" of $250.
Q. At least I know there's no more free food on the airlines, so I'll make sure I have a $10 in my wallet to buy a sandwich.
A. You're right about no free food, but that $10 won't buy you a sandwich. These days, U.S. airlines accept credit cards only.
This work is the opinion of the columnist and does not reflect the opinion of ABC News.
Rick Seaney is one of the country's leading experts on airfare, giving interviews and analysis to news organizations that include ABC News, the New York Times, the Wall Street Journal, Reuters, the Associated Press and Bloomberg. His website, FareCompare.com, offers consumers free, new-generation software, combined with expert insider tips to find the best airline ticket deals.