On the Friday after Christmas two years ago, more than 13,000 passengers - out of food, water and patience - were stuck in planes that had been circling closed airports or idling on tarmacs for as long as 11 hours.
Those flights launched consumer advocates and the air-travel industries on a quest for a national bill of rights for fliers.
But this season, travelers will be just as exposed to the whims of the weather, air-traffic congestion, and cash-strapped airlines.
Efforts to pass legislation have failed because of airline lobbying against obligatory rules and recognition that travel woes come in too many shapes and sizes for any law to prevent an encore of the 2006 holiday horrors.
"We missed the peak again," said Kate Hanni, a Northern California real estate agent whose "imprisonment" on a plane that Dec. 29 prompted her to found the Coalition for an Airline Passengers' Bill of Rights. "As of today, the airlines can keep you stranded indefinitely on the tarmac in a sealed metal tube, and there's nothing you can do about it."
Those who want a bill of rights have pinned their hopes on the next Congress. But by even the most optimistic projections, travelers would gain legal guarantees no sooner than summer.
Legislation that never made it out of the Senate transportation committee this year must be resubmitted when Congress convenes in January, and Sen. Barbara Boxer (D., Calif.) plans to offer a draft bill, said Natalie Ravitz, the senator's spokeswoman.
The rights being sought include the opportunity to deplane if tarmac delays extend beyond three hours; inter-carrier honoring of tickets when an airline suspends service; penalties for lost bags; accommodation and food vouchers for long delays; and more transparency into airlines' fare schedules, on-time records, and refund policies.
Some progress has been made since 2006. Transportation Secretary Mary E. Peters created the so-called tarmac task force, but the industry-dominated group agreed only on "model contingency plans," detailed in a 58-page report in November.
New York state legislators adopted a law that took effect New Year's Day 2008 that requires airlines to stock water and snacks and to provide working restrooms and fresh-air infusions when planes have been grounded for more than three hours.
Language on passengers' rights was written into a bill this year to restructure the Federal Aviation Administration, but the bill died in the last congressional session.
The Air Transport Association, the trade group representing the principal U.S. airlines, recognizes that tarmac delays are a problem, but objects to taking decision-making out of the cockpits and control towers.
"One lengthy tarmac delay with inhumane conditions is one too many, and we are working hard to make sure that doesn't happen," spokesman David A. Castelveter said. "But we are vehemently opposed to a mandatory three-hour rule."