There's usually no need to panic when planes make emergency landings. Here's why

After a door plug blew out from an Alaska Airlines flight in January, igniting a scandal about safety practices at Boeing, some people have been nervous to fly.

It hasn't helped that news articles have spotlighted various emergency landings in the months since the incident.

But it's incredibly rare that anyone is killed or even injured on a commercial flight, especially a flight in the U.S., including on Boeing planes. Major U.S. airlines are in the midst of a remarkable safety streak, with none of them having a fatal crash in the U.S. in 15 years.

The FAA handles 45,000 flights per day with 2.9 million passengers aboard. Data from the National Transportation Safety Board shows only a handful of problems on commercial passenger jets happen in any given month.

It might be unnerving to read that a plane had to make an emergency landing, but it doesn't alarm pilots.

"Things that appear really dramatic to non-aviation folks, in a lot of ways, really are not," says Shawn Pruchnicki, who is a professor at The Ohio State University in aviation and a former commercial pilot.

Here are a few things to know about plane safety and what happens when things do go wrong.

Planes are made with multiples of the important parts

In March, a plane leaving San Francisco lost a wheel after taking off. The plane was diverted to Los Angeles, where it landed safely.

That safe landing was possible because there are at least two wheels on every part of a landing gear, Pruchnicki says, in case one wheel falls or a tire goes flat.

It's called redundancy: having doubles or triples of critical systems in case one fails.

When it comes to the generators that create electricity for everything from reading lights to flight displays, "typically, for almost every commercial jet out there, there's three of them," Pruchnicki says.

There's redundancy in other crucial systems: the air data computers that generate numbers like airspeed and altitude, the hydraulic systems used to operate various parts of the plane, and the cabin pressurization systems that keep the air inside safe to breathe.

Most commercial passenger jets also have two engines and can operate for long distances with just one of them functioning.

Planes can even glide down with no engines working, most famously when Capt. Chesley "Sully" Sullenberger landed an Airbus A320 in the Hudson River in 2009 after hitting a flock of geese. Everyone on board survived.

Pilots and crews train extensively to prepare for things going wrong

In flight simulators, pilots practice how to handle scenarios like landing in low visibility, having to abort a landing, dealing with a fire on board, or working through various equipment failures.

Situations like flying a plane with one engine are practiced in simulators all the time, says Douglas Boyd, an aviation research professor who directs a fear-of-flying program in Houston. "They're not really raising the heart rate of the pilot because they're so routine," he says, though they still require the pilot to divert the plane and land early.

And when it comes to flight attendants, "there's a big misconception" that their main job is serving drinks or helping passengers find their seats, says Anthony Brickhouse, a professor of aerospace safety at Embry-Riddle Aeronautical University in Daytona Beach, Fla. Instead, "the primary role of flight attendants is safety," he told NPR in March.

Cabin crews are trained to lead evacuations in emergencies; United Airlines notes in a job description that flight attendants need to be able to operate oxygen systems, aircraft doors, evacuation slides, fire extinguishers, life rafts and communications and lighting systems.

Emergency landings aren't necessarily "emergencies"

The phrase "emergency landing" is a bit of a misnomer used by the media, pilots say. They're more often called "diversions" by pilots when the plane is forced to land somewhere other than the intended destination. It's usually not because the plane is in immediate danger.

"I have made numerous diversionary landings where I wasn't concerned about the safety of the airplane at all," says John Cox, a longtime pilot and founder of the aviation consulting group Safety Operating Systems.

For example, news articles have covered multiple incidents of planes diverting due to cracked windshields.

Cox says a crack would usually happen just in the inner layer of the windshield, which has two layers of glass as well as a layer of plastic. The flight crew will want to lower altitude to ease pressure on the windshield, affecting fuel calculations, and the cracked windshield could alter a pilot's view. So "you don't really want to do that for a longer period of time than is necessary," he says.

Still, in these situations, "it's not a safety issue. I'm just going to take action to prevent a safety issue from arising," Cox says.

If pilots do declare an emergency, Pruchnicki says, they get to skip the queue to land and get to choose which runway to land on.

Also, declaring an emergency frees pilots from following "hundreds and hundreds of tiny little regulations," he adds — including speed limits.

"A lot of the reasons why we declare an emergency is because it just gives us all this freedom to deal with whatever problem we're dealing with and not have to worry about all these other things," Pruchnicki says.

Injuries from turbulence are more common, but still rare

If you have to worry about something (though you don't really have to worry), pay attention when the captain warns about turbulence.

More than a third of commercial airline accidents involving a serious injury are caused by turbulence, according to a 2021 NTSB report.

"That's a leading cause for diversions, because if I've got injured people in the back, we're going to divert," Cox says. "I want to get them medical attention."

Still, injuries from turbulence are rare and most often happen to flight attendants, who aren't able to stay buckled in their seats all the time. In 2022, just four passengers and 13 crew members were seriously injured by turbulence, according to FAA data. (Airlines aren't required to report more minor injuries.)

The best thing you can do as a passenger, as you are constantly reminded: Keep your seat belt fastened.

"The system is still safe"

The spotlight on Boeing has some people nervous about their planes. There are legitimate concerns about Boeing's quality control and that of its subcontractors.

But Cox, for one, has no qualms about flying on Boeing or other commercial planes. There has not been a fatal plane crash involving a major American airline in the U.S. since 2009 (though in one notable case, one person was killed on a Southwest Airlines flight in 2018). For comparison, more than 40,000 people are killed on U.S. roads each year.

"The system is still safe," Cox says. "Does that mean that we that we should lose our focus on safety? Absolutely not. Aviation did not get to be the safest form of transportation ever designed by humankind by not continuing the quest for better quality. And that needs to continue."

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