Airport Avenger: Tips and Top Secrets for Airlines, Airfares, Fees, Security and Cancelations

A lot of people plan trips and compare fares on weekends. That's probably not the best time to find a deal.

Weekend fares tend to be more expensive. For one thing many airlines hand fare prices over to computers on the weekend. As soon as the cheapest seats are gone, they start selling the more expensive ones. When a human takes over again, he or she may offer more cheap seats.

A few sales and deals may pop up on weekends, but you're likely to find more if you check late Monday or early Tuesday. Sales often start between Sunday night and Tuesday morning, and airlines tend to match their competitors’ prices within a day or so.

Airlines have raising fares. You're most likely to see fare increases on a Thursday night. If they don't stick over the weekend (if other airlines don't match whoever got the ball rolling) they'll probably be rolled back by Monday.

• Wednesday is often the cheapest day to travel, except perhaps near holidays, because fewer people fly on Wednesdays. You can also save money on Tuesdays and Saturdays for the same reason.

• Flying early or late in the day can also mean a lower fare because those flights often aren’t as full as the midday ones.

• Airlines have gotten more selective with fare sales, especially for the peak summer travel season, which wasn't so peak a year ago.

• Business travelers, the Holy Grail for major carriers, stayed away in droves. Many people may decide it's better not to fly to a vacation destination, given the shaky state of jobs and the economy.

• Most sale fares are for particular flights on particular days. Airlines want to fill flights that usually aren't full.

• Peak travel days are usually excluded from sales. Lots of people will pay higher fares on those days.

• Advance purchase is required, often 14-21 days.

• No refunds. If you have to change your plans, in most cases you'll pay a hefty fee.

• Minimum and maximum stays may be part of the deal.

• Don't forget to include taxes and fees. Still a bargain?

• Shop around. Chances are other airlines will match a sale price or do even better.

• Check online booking sites for deals.

The major airlines came up with a new--some would say sneaky--way to raise airfares around the Thanksgiving and Christmas holidays in 2009, without actually calling it a fare increase. They tagged on a $10 to $30 surcharge for tickets on peak days. It worked so well that they did it it again in 2010 and in 2011.

You won't see the surcharge itemized with other taxes and fees that go into your ticket. The airlines can tuck it into the fare without pointing it out.

Compare fares and be flexible with your travel plans. You could save some cash just by flying a day or two before or after you planned to go.

Why a surcharge instead of an outright fare increase? It's easier, more discreet and more profitable to put an almost-invisible surcharge on fares across the board instead of raising fares route-by-route and running up against competitors in some markets that will undercut you.

And when the surcharges are lifted for a while: Poof! Instant fare cut. Or is it?

More tips and top secrets about airfares:

Don't Get Jumpy

Weekend Airfare Wonders

Find Stealth Airfare Deals

Airlines and Airports on Twitter

Tracking Traffic