NEW YORK (BLOOMBERG) - Air traffic for the Thanksgiving holiday is expected to approach pre-pandemic levels and travellers are likely considering their plans with some dread, given fresh memories about thousands of cancelled flights.

"The process of getting there is going to be difficult," said Mr Stephen Beck, founder of management consulting firm Cg42.

"We're going to have to prepare ourselves for the frustration that lies ahead. That's generally where the average consumer is."

US airlines say they're prepared for what looks to be the busiest holiday travel period since the Covid-19 pandemic began.

"We're ready for it and excited about it," said Mr Doug Parker, chief executive officer of American Airlines Group Inc.

Most planes across the industry will be near full capacity, he said last week at an online forum hosted by the Skift trade publication.

"People are wanting to travel, wanting to go see family over the holiday or travel over the holiday," Mr Parker said.

"It's going to be a busy travel season."

Roughly two million people a day are projected to fly from Nov 19 through Nov 28, according to the Transportation Security Administration, with the potential for some days to exceed that average dramatically.

Passenger traffic for the last five days of that period would be just 9 per cent below 2019, before the pandemic hit, according to non-profit travel group AAA.

United Airlines Holdings Inc expects to fly more than 4.5 million passengers, about 88 per cent of its 2019 level, from Nov 19 through Nov 30.

Delta Air Lines Inc anticipates flying around the same level, carrying at least 5.6 million customers.

American and Southwest Airlines Co didn't provide similar projections, but they're the airlines that consumers might be most concerned about, after the carriers were wracked by cancellations last month.

Storms combined with staffing shortages after the carriers resumed service too enthusiastically from pandemic lows, meaning thousands of flights had to be scrubbed.

Both companies have since reduced flying, brought workers back from leave, hired new ones and offered incentives in the hopes employees won't miss work over the holidays.

United CEO Scott Kirby said on Bloomberg Television that he's "confident" the carrier is fully staffed for the holiday crunch and won't experience operational problems.

Unions also say they're prepared, assuming meteorological forces cooperate.

"It's really important for people to remember what they knew about airline travel two years ago," said Ms Sara Nelson, president of the 50,000-member Association of Flight Attendants-CWA.

"If there's weather, we're going to see delays."

Would-be travellers seem optimistic. Tickets sold in the US for domestic and international trips during the 14-day Thanksgiving travel period were 11 per cent below where they were in 2019, according to Nov 14 data from the Airlines for America lobbying group.

"People aren't going to be deterred by the possibilities of storms and delays," said Ms Christie Hudson, a spokesperson for travel services provider Expedia Group Inc.

"The pent-up demand is a huge factor, especially if you didn't get to see your grandparents or family members last year or had to cancel trips earlier this year. Our mentality now is, 'Screw it, I'm going."'

Weather and typical holiday travel snags aside, there are reasons to be particularly wary this year.

The nationwide labour shortage and tight staffing that's lingered from the depths of the pandemic have left many airport employees and flight crews stressed from working heavy overtime.

Airline workers also have had to contend with a spate of belligerent passengers amid the pandemic.

Also, the busy run-up to the holiday coincides with a Nov 22 deadline for federal workers, which includes airport security screeners, to get Covid-19 vaccinations.

Many Transportation Security Administration officers haven't gotten the shots, according to Mr Hydrick Thomas, the president of the American Federation of Government Employees union division that represents frontline TSA workers.

The agency, which has just completed a hiring surge, and the union said they don't anticipate disruptions.

Federal guidelines allow for gradual measures to ensure vaccination compliance so there won't be mass firings during Thanksgiving week or immediately after, the TSA said.

Even if there are longer security lines and flight delays, some travellers won't be fazed because they can build in extra travel time, taking advantage of the pandemic's shift toward more workplace flexibility.

That allows people to take longer breaks from the office to avoid peak travel days, said Mr Mike Daher, a transportation and hospitality consultant for Deloitte.

About 75 per cent of travellers plan to add at least one day to their holiday trip because they can work on the road, according to a recent Deloitte study.