Over all, the cuts will reduce flights this year by American carriers by almost 10 percent, industry analysts estimate, with even deeper cuts in store for 2009. And if oil prices keep rising, airlines may have to keep paring their schedules, as they struggle to find ways to make money in light of rapidly rising jet fuel prices, which have climbed more than 80 percent in the last year.

This week, the country's two biggest airlines, American and United, announced plans to lop cities like Fort Lauderdale, Fla., and San Luis Obispo, Calif., out of their networks. Cuts also are taking place on international routes to cities like London and Buenos Aires, and even to popular vacation destinations in the United States like Las Vegas, Honolulu and Orlando.

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Air fares, which are up about 17 percent this year on average, may rise as much as 40 percent within the next four years, Mr. Chase predicted. And airlines continue to add fees -- Delta said Friday that because of high fuel costs, it will start charging up to $50 to book a frequent-flier awards ticket. American and US Airways also recently announced they would charge to book tickets using miles.

Leisure travel falls in September, so occasional fliers may first encounter the harsh new reality of flying at Thanksgiving, with fewer flights and less-convenient connections. By year's end, roughly 100 American communities will be left without regular commercial air service, and that number may double next year, according to the Air Transport Association, the industry trade group.