Mario Nunez called it a "huge shaking my head moment" when the photo inside the cabin of Southwest Airlines flight 1380 appeared on his TV.

The story was about a terrifying emergency landing after an engine exploded 20 minutes into a trip from New York to Dallas, rapidly depressurizing the cabin and killing a woman who was pulled outside. It was a story of a pilot with seeming nerves of steel, who brought the plane down safely for the other 143 passengers on board.

But for Nunez, a Tampa resident who spent 30 years as an American Airlines flight attendant, what immediately jumped out was that the passengers in the photo were wearing their oxygen masks incorrectly.

"Place it firmly over your nose and mouth, I must have said that ten thousand times," Nunez said, echoing the instructions to place the mask over your nose and mouth and pull strap around the back of your head that are part of every flight. "I retired in 2013, but I saw this and immediately it brought me back. It's a perfect illustration of why people need to pay attention."

"They might as well have been wearing it on top of their heads," said Sara Nelson, who has been with United Airlines for 22 years and is currently president of the Association of Flight Attendants, a union representing more than 50,000 people.

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Flight attendants know their audience is mostly tuned out when they explain how to buckle seatbelts, wear oxygen masks and use seats for flotation devices.

Sandy Stein, of West Hills, Calif., who retired after a 30-year career with Delta and described the mask-wearing in the photo as "appalling," said she remembers testing to see if passengers were paying attention by using a rubber chicken.

"I let the chicken unfurl from the area where the oxygen masks are stored and put it over my nose and mouth waiting for some sort of giggle," Stein said. "Nothing happened. I stood there. Finally one of the passengers that was sitting close to where I was standing looked up and laughed."

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The challenge of grabbing passengers attention has only become harder, Nelson said. As seats have gotten closer, and cabins more cramped, people are trying harder to tune out and calm themselves before takeoff. And even when people do comply with putting their phone on airplane mode, they're still staring at it with headphones in," she said.

And both Nunez and Nelson agreed, the change from flight attendants giving the instructions verbally to delivering them via video, as approximately two-thirds of all flights do now, has made people feel even less inclined to listen.

"They're done by marketing departments instead of safety people," Nelson said. "You've got seatbelt demos happening in the middle of a cabaret show, and kangaroos showing up."

But there are plenty of reasons for passengers to familiarize themselves with the safety instructions, especially as they pertain to seatbelts and oxygen masks, Nunez and Nelson said.

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For starters, if the cabin depressurizes and you're not getting enough oxygen, you could fall victim to hypoxia, which can lead to dizziness, confusion and passing out. That could lead to missing some other crucial instructions from the crew that could save you life, Nelson said.

"You've got maybe 10 seconds of oxygen without your mask before that happens," Nunez said.

And if a cabin depressurizes, the pilot is going to have to make maneuvers to bring the plane down to 10,000 feet where people can breathe naturally. Fast. Making the seat belt very important. Nelson said adult passengers and babies have stayed firmly in their seats in otherwise perilous situations, thanks to the belt.

Regardless of whether the seatbelt light is on, Nunez said, if you're seated, you should be buckled in because a plane can hit clear air turbulence out of nowhere.

"That's when your head hits the ceiling," he said. "I've seen a 300-pound beverage cart come two feet off the floor, with me on top of it."

As a refresher, here's what's said on every flight:

"In the event of a decompression, an oxygen mask will automatically appear in front of you. To start the flow of oxygen, pull the mask towards you. Place it firmly over your nose and mouth, secure the elastic band behind your head, and breathe normally. Although the bag does not inflate, oxygen is flowing to the mask. If you are travelling with a child or someone who requires assistance, secure your mask on first, and then assist the other person. Keep your mask on until a uniformed crew member advises you to remove it."

Contact Christopher Spata at cspata@tampabay.com. Follow @spatatimes on Twitter. Information from the Associated Press was used in this report.

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