John Hanks is going to London twice this month, but he won't set foot near Big Ben, Buckingham Palace or the British Museum.

The retired Phoenix salesman won't get any farther than an airport Hilton, where he'll rest until it's time to fly home the next day.

Hanks, 64, is making the whirlwind trips solely to rack up frequent-flier miles on US Airways.

It's called a mileage run, and mileage junkies everywhere schedule them this time of year to keep, or upgrade, their frequent-flier status with an airline for next year. Some never step outside the airport, or even the gate area. The savviest among them trade mileage-run strategies and fare deals on Web sites such as www.FlyerTalk.com.

Airlines dole out free first-class upgrades, set up separate check-in and security lines, unload bags earlier and give bonus miles to their most frequent fliers.

The more miles flown, the higher the status and better the benefits. The 23,000 miles Hanks earns on the London trips will push his mileage over the 100,000 mark he needs to stay in the top tier of US Airways' program next year. That means another year of double frequent-flier miles and the earliest shot at free first-class upgrades.

"You get used to the perks," Hanks said. "I wouldn't have it any other way."

Travis Christ, vice president of sales and marketing for US Airways, said the Tempe, Ariz.-based airline notices a spike in travel among its most frequent fliers each fall. Hotels see it, too, as their frequent guests do mattress runs to keep their status.

"It's worth doing these mileage runs because it makes their life so much better for another year," Christ said.

Hanks is fortunate that he's retired and doesn't have to squeeze in his London red-eye flights between business trips. The vast majority of airlines' top frequent fliers are business travelers already on the road a lot, and the race to bulk up their mileage balance makes things even more hectic at work and at home.

"When you're hanging out there at 25,000 (miles short) you get nervous," said Dave Bost, a frequent flier in Scottsdale, Ariz., and a strategic development director for an environmental consulting firm.

He should know. As the summer ended, Bost was about 23,000 miles short of the 75,000 miles he needs to be in the second-highest tier of US Airways' program.

He is in the top tier this year but only because of a promotion tied to last year's America West-US Airways merger.

Bost looked at his business travel plans for the rest of the year, mostly back-and-forth trips to California, and calculated that he would still be about 13,000 short.

Bost literally went out of his way on his most recent mileage run to rack up more miles, hopping from Phoenix to Las Vegas to Philadelphia to Jacksonville, Fla.

Airlines don't mind them, of course, because they are trips that otherwise wouldn't have been booked, and they breed loyalty the following year if they help customers retain their status.

There is usually no way around booking extra flights to rack up miles because most airlines don't count miles earned on credit cards, hotel stays, car rentals and other partners toward preferred status.