For travelers, high-quality mobile applications are crucial for catching flights and getting to where they need to go without problems. Americans might be able to deal with long lines at TSA, but if there is one thing they have no patience for, it’s slow or crashing sites and apps. And a recent 2016 Holiday Travel Survey from ScaleArc delves into just how unforgiving flyers are.

After experiencing his own frustrations with an airline’s mobile app, ScaleArc’s CEO, Justin Barney, got the idea to conduct a survey to see what consumers think about their airline mobile or web app experiences. This survey was conducted in November among 1,008 adults ages 18 and older, and was fielded on Google Consumer Surveys.

(Related: How IT teams can prevent outages this holiday season)

According to Barney, an interesting find from the survey was that a full third of Americans have experienced underperforming airline booking sites and apps in this year alone. When these sites underperform, 68% of Americans admit to taking retaliatory action, such as going to a competitor and booking through a different site (31%), and flying with a competitor (17%). Nine percent of Americans said that they might never fly with an airline again if they have a booking site that performs poorly or stops working while they are booking a flight.

One reason why airlines run into a bit of trouble around the holiday season is because of the change in weather. A dramatic change in weather gets consumers wondering if they should cancel or rebook their flights in order to make it home to see family in time for the holidays, and this causes a surge in traffic to the websites or apps that airline companies insist consumers use, said Barney.

“If airlines have not worked to make their apps consumer-grade, they will run into problems,” he said.

Another reason why many airlines experience issues with their applications and mobile sites has to do with data centers and databases, according to Barney. He said that data centers were designed to conduct business with applications, and while there are a lot of technologies for the web traffic and there are companies that scale technology for web technology, the “database is the Achilles heel.”

“Because the database uses an old protocol, not the web protocol, it uses an old protocol that was never designed in the 1970s for today’s world,” said Barney. “So it is old, and crusty, and archaic, and it’s almost, basically, the opposite of never-down, always-fast and scale-anywhere.”

He added that the database is what ScaleArc sees as the biggest technology challenge that prohibits apps from performing, especially when it comes to scaling and handling more users.

Airline companies have a few options if they want to adopt modern, scaled databases. One option is to recode their apps and spread out the load and traffic to additional database servers. The problem, however, is that this costs time and money, especially if companies want to buy the latest software, recode their applications, and move them to the cloud.

Some airlines are already in the process of changing their infrastructure so they can handle more load, like American Airlines, which announced at the end of November that it selected IBM’s Cloud to move over certain enterprise applications and “refocus its business goals to the needs of the customer and the business of airline travelling,” according to Patrick Grubbs, IBM’s vice president of travel and transportation.

A Forbes report said that Endeavor Air, Virgin America and WestJet are just a few airlines that also adopted cloud computing systems for their own aircraft maintenance records and passenger services.

However, according to ScaleArc’s survey, American travelers are still concerned about which booking sites will go down over the holidays. Ten percent were worried about Southwest Airlines and United Airlines, and the top fears of Americans is that their time with loved ones will be cut short due to airline database crashes (21%).

“[Another way] to achieve consumer-grade experience would be investing in more databases, more people, and recoding the apps, and that’s just the piece of it that used to be okay,” said Barney. “Now that we’re in a digital world, and every enterprise is focused on digital transformation and launching 50 to 100 new applications every year to drive business value, that old way of doing things just doesn’t work anymore.”