takeoffAt this point it’s hardly a question of “if” there will be new airline fees on tickets, but rather “when” and “what” they will be.

And sure enough, as travelers begin to think about Thanksgiving and end-of-year travel, the latest is a “holiday surcharge.” Initiated by United Airlines and American Airlines, and so far matched by US Airways and Delta-Northwest Airlines, the surcharges — for now — are only $10, and only on three days – November 29, 2009, January 2 and 3, 2010.

The operative word is “for now.” Most new airline charges are trial balloons. If they fly, they stay, if they don’t – as in US Airways’ former soft-drink and bottled water charges, they vanish into history. At least for a while.

Some travelers might wonder, why bother adding a surcharge? Why not just blackout discount fares on popular travel days, or limit seats?

The answer is that airlines do that, too. But from a revenue standpoint, the surcharges have several potential advantages.

First, surcharges are exempt from any potential corporate or other discounts. Which means they are undiluted revenue.

Second, a “holiday surcharge” can be placed in the fine print of an ad, along with all the other taxes and fees that few people without super-hero level vision can read easily.

Third, surcharges affect all fares. And while they may be most noticeable on the lower super saver airfares, from an airline point of view, why not make a little extra on the full price tickets for those days? (Especially with late-booking business travelers unlikely enough to have to fly on the Sunday after the holiday, who are most likely going to be paying high prices anyway.)

Fourth, surcharges can be adjusted easily at will, increased and/or expanded if they meet with little resistance, quietly dropped if they aren’t working out or the negative publicity outweighs the extra money.

Admittedly, 2009 is a tough year for airlines, so it’s hard to fault them for trying to boost their bottom line when possible. But since these surcharges are aimed squarely at leisure travelers, who are often watching their own budgets these days, will they be one more push in the direction of staying home for the holidays?

(Photo: brendan/Flickr Creative Commons)