You are settling into your window seat, bound for a summer vacation, when the flight attendant wishes you a happy birthday or commiserates about the lousy weather that delayed the last leg of your trip.

It might feel like the flight crew has been scouring your recent social media posts, but at some airlines, that wouldn't be necessary.

Carriers such as United Airlines, Delta Air Lines and Southwest Airlines are giving gate agents and flight attendants access to more customer data in hopes of giving passengers more personalized service.

Still, there is only so much a birthday greeting can do to make up for a lost bag or late arrival, particularly when airlines want to steer clear of conversations that feel too personal. While in-cabin recognition might be the most visible way airlines are working to do more with the troves of data they collect, behind-the-scenes efforts to mine stats on everything from collisions between airport vehicles to turbulence touch almost every piece of a passenger's trip.

Most of the data they are working with is the sort of information airlines have long collected. And there's no shortage: a Boeing 787 generates half a terabyte of information per flight, said John "JJ" DeGiovanni, a managing director with United's corporate safety team. The challenge is figuring out how to use it in ways that are meaningful for the airline and its passengers.

When it comes to personalized service, just how meaningful today's programs are depends on whom you ask.

Jay Sorensen, president of airline-consulting firm IdeaWorks, said he's skeptical that employees would have the right kind of information — or the time — to add real value for fliers, outside of a handful of cases, like helping passengers at risk of missing a connecting flight get off the plane first. Even if an airline could anticipate your drink order, placing it isn't a strenuous task, he said, and flight attendants have other tasks to juggle.

"In coach, it's just not going to happen," Sorensen said.

But passengers do seem to appreciate the personal touch, said Allison Ausband, Delta's senior vice president of in-flight service. Delta aims to have those personal interactions with about 20 travelers per flight, either in conversations or through postcards that flight attendants can hand-deliver. Priority goes to those who had some type of disruption on a recent flight, such as a lengthy delay.

"They want us to know them and know what's happening to them when they're doing business with us," Ausband said.

For now, most of the passenger information that flight attendants can access to personalize in-flight service is the sort of thing airlines already track, such as frequent flyer status, or details included in every booking, such as a passenger's date of birth and connecting flight.

Southwest Airlines is testing a program that would help customer service agents spot "key customers" at the gate, where they can try to resolve a problem or just wish the passenger a happy birthday, spokesman Dan Landson said.

Giving flight attendants and gate agents access to that information wasn't practical until they began carrying mobile devices that do double duty, accepting payments for in-flight purchases and tracking which passengers are entitled to perks like a drink or meal, said Robert Mann, a New York-based airline industry consultant.

At United, those devices also can issue immediate compensation for in-flight issues like a broken entertainment system. Options can include free food or drink, frequent flyer miles or another form of credit.

Airlines also say they are trying to strike a balance between a welcome personal touch and getting a little too personal. What one traveler considers great service, another might find invasive.

"No one wants to feel like they have Big Brother watching us," said Scot Hornick, partner at consulting firm Oliver Wyman.

That's less of a concern with data-driven programs that aren't as visible but still have an effect that passengers can feel — literally, in the case of one tool that Delta developed for its pilots.

The app provides information about weather hazards like turbulence, lightning or hail that's more accurate and easier to interpret than pilots used to be able to get after takeoff, said Tom Staigle, Delta's chief technical pilot.

Even if a plane's crew doesn't adjust its route to avoid turbulence, knowing when to expect it helps prevent injuries and limits the amount of time that passengers must be seated with belts fastened, Staigle said.

Other airlines say they are mining data on aircraft damage and worker injuries.

Efforts to analyze causes of preventable aircraft damage, such as collisions with vehicles at the airport, might not sound like something a passenger should care about. But that kind of damage often results in a cancellation unless the airline can quickly swap in another airplane, which still typically involves a delay, Mann said.

Incidents of preventable aircraft damage are down 25 percent from 2015, and employee injuries have dropped by 13 percent, according to United.

The airline had been tracking and issuing reports on both damage and injuries long before using data visualization. But when information was listed in a spreadsheet, it was harder for employees to figure out what it meant, said DeGiovanni, of United's corporate-safety team.

When it's displayed visually, "You say, 'Oh my god, what's going on on the north side of C Concourse?' It's easily digestible, and anyone from front line to the CEO can say, 'Why is that dot red?' " he said.

Insights from the visualization program have helped United reduce the rate at which aircraft are damaged from 2.8 incidents per 10,000 flights in 2012 to about 0.8 per 10,000 flights today, United said.

Collisions with jet bridges, which connect aircraft to the airport terminal, were a common source of damage, so the airline began putting markers on planes to help jet-bridge operators avoid hitting them.