Phoenix ? Your ginger-ale doesn’t come in a glass anymore on most US Airways flights. On Delta you’ll find yourself in a thinner, lighter seat. If you fly JetBlue cross-country, you’ll get a dainty bag of 100-calorie crisps in place of the original snack box of cookies, crackers and spreadable cheese.

With jet fuel prices so high, airlines have no choice but to scour their planes for ways to lighten the load. There’s no room for even the smallest bits of dead weight, from redundant wing lights to extra wires in the walls. Manufacturers also are using lighter materials in plane construction.

“The pressure is immense” to cut weight, said John Heimlich, chief economist for the Air Transport Association of America, an industry trade group. “Every penny more per gallon adds $195 million to the industry’s expenses per year.

“You simply cannot make all of that up with fare increases.”

Jet fuel, which the Energy Department’s Energy Information Administration tracked at $3.17 per gallon in New York on Tuesday, has doubled since the beginning of 2007. It outpaced labor as the biggest airline expense three years ago. As of September 2007, fuel made up 27 percent of operating expenses for U.S. airlines, according to the latest data from the Bureau of Transportation Statistics.

The industry has struggled to keep up. Carriers have increased fares, cut capacity, parked their gas guzzler planes, charged customers to check a second bag, trimmed staff and pushed as many passengers as possible to automated kiosks.

Airlines also try to exert some control over fuel expenses through hedging, a practice of capping fuel prices months or years in advance with long-term contracts.

But hedging is still a gamble.

“Reducing consumption is a certainty,” Heimlich said. “You’re always going to win by consuming less energy.”

To that end, carriers have pulled out unused ovens, magazine racks and trash compactors during the past few years. Some removed paper manuals in the cockpit and installed electronic maintenance logbooks.

Fort Worth, Texas-based American Airlines created a Fuel Smart Team in 2005 as fuel prices started to go up. Tom Opderbeck, American’s manager of strategic programs, said the team tried to cut weight in places that customers wouldn’t notice.

The team capped electrical outlets in the lavatories and cut the power converters from the wall. It took out phones in seat backs and removed the heavy telephone wiring that was folded inside.

“I always think we’ve come to the end of the list, but we keep on finding new items” to remove, Opderbeck said.

The weight-savings measures were unrelated to the grounding this week of MD-80 planes operated by American, a company spokesman said Friday. American and Delta Air Lines both had to cancel flights after Federal Aviation Administration inspectors questioned whether the airlines had properly performed a modification. A $10.2 million civil penalty imposed by the FAA on Southwest Airlines this month also was unrelated to fuel-saving measures.

Last year, American replaced its silverware on business and first class with another set that was made from a lighter metal.

“Every little bit helps, especially for an airline like American Airlines that flies over 750,000 flights a year,” Opderbeck said.

American Airlines burned 2.8 billion gallons in 2007. After the recent weight cuts, the carrier estimates it will conserve about 111 million gallons this year.

JetBlue’s aircraft are 1,079 pounds lighter after removing extra trash bins, flight kits, supplies and seats – “all the little things that, when combined, make a decent difference,” JetBlue spokesman Bryan Baldwin said.

The weight loss will save the carrier roughly $16,000 per day, he said.

Southwest Airlines cut fuel costs simply by flying more direct routes. The Dallas-based carrier equipped planes with life vests during the past two years, allowing pilots to fly over bodies of water and shave miles off of their flights.