DENVER — On the 30th anniversary of a catastrophic airplane crash that killed 11 children, the union representing flight attendants is renewing its call for stricter child safety rules on airplanes.

The Association of Flight Attendants wrote a letter to lawmakers and FAA officials this week, imploring them to mandate that every passenger have a seat with a proper restraint, effectively doing away with so-called “lap kids,” or children under the age of 2 who are allowed to sit on their parent’s lap during a flight.

The renewed push is in conjunction with the anniversary of the crash of United Flight 232  The DC-10 departed Denver’s Stapleton Airport on the afternoon of July 19, 1989, bound for Chicago. An hour into the flight, it suffered an explosive engine failure, and pieces of the tail engine’s fan disk destroyed the airplane’s hydraulic systems, making it nearly impossible to control. The plane’s captain was forced to land in a corn field just shy of the airport in Sioux City, Iowa.

Of the nearly 300 people on board, 112 were killed.

“(Flight) 232 started off as just a normal flight, and ended up being one of the most famous disasters in aviation history,” Steve Cowell, an aviation safety expert, told FOX31.

“I was just in awe how anybody could’ve possibly survived,” he said. “One of the first things that happened was the nose of the airplane broke off like a pencil tip. There was nothing in the United manuals that spoke to anything like this, or the remote possibility of anything like this happening. They didn’t have a procedure,” Cowell said.

The legacy of Flight 232 is the many changes brought about because of the crash.

“It changed so much afterward. Changed the way engines are made, changed United Airlines’ inspection procedures, it changed the way hydraulic systems are located in an airplane,” Cowell said.

But the one crucial thing that has not changed is how to handle “lap kids.”  In the moments before the crash of Flight 232, flight attendants were instructed to tell passengers to put their “lap kids” on the floor of the airplane. It was airline procedure at the time, but it wasn’t safe, because the kids became projectiles upon impact. So a fix was made.

“And they developed a child restraint system, but unfortunately, to this day, the FAA has never mandated the use of child restraint belts on an aircraft,” Cowell said.

He believes it’s time for airlines and the FAA to get more serious about child safety.

Cowell also says that there is one thing we can all do to stay more safe during flight: listen to the safety briefing.

“There’s no excuse for not putting down the headphones, for not listen to the flight attendant. To think about that for 30 seconds could save your life,” Cowell said.

To learn more about the safety issues onboard Flight 232, and hear the stories of survivors, watch this FOX31 web special, “Retro Colorado: Flight 232.”