Capt. Tammy Jo Shults, the pilot who landed a Southwest Airlines plane last month after one of its engines exploded and blew a hole in the cabin, has been widely hailed as a hero for her calm nerves and steady leadership during the harrowing mid-flight ordeal.

But the way she describes it, the flight began just like any other day at the office.

“It was really like any other flying day,” Shults, 56, said in an interview with ABC News’s “20/20” that will air Friday.

Shults wasn’t even supposed to be flying the plane.

Her husband, Dean, also a Southwest pilot, had been scheduled to be Flight 1380’s captain but the two had swapped shifts so she could attend their son’s track meet.

“Dean, being the amazing husband he is, said, ‘You go to the track meet, I’ll switch and take your trip.’ ” Shults said. “And so that’s why I was on the trip.”

She and her co-pilot, Officer Darren Ellisor, 44, a former Air Force pilot, said everything seemed normal as the flight took off from La Guardia Airport in New York. But it didn’t take long for the plane to find itself in trouble.

There was a jolt as the aircraft ascended to about 32,000 feet.

“We had a large bang and a rapid decompression. The aircraft yawed and banked to the left, a little over 40 degrees, and we had a very severe vibration from the number one engine that was shaking everything,” Ellisor said. “And that all kind of happened all at once.”

Shults, who was reportedly one of the first female fighter pilots for the U.S. Navy, said the trouble reminded her of some of the training she had done for the military.

“My first thoughts were actually, ‘Oh, here we go.’ Just because it seems like a flashback to some of the Navy flying that we had done,” she said.

The cockpit was so loud that she and Ellisor had to use hand signals to communicate.

They initially thought the problem might have been a seizure of the engine’s air, but quickly realized their problems were more severe as the plane had depressurized.

Shults told air traffic control that they wanted to land the plane in Philadelphia. As the captain, she took over the controls to land the plane in Philadelphia, ABC reported.

“At that point, we really just — because of the noise and different things — we had to be flexible and just use things that we had learned in previous training,” she said. “And we kind of just split the cockpit and I did flying and some of the outside talking, and he took care of everything else.”

Both pilots wore oxygen masks, ABC reported.

One passenger, Jennifer Riordan, a 43-year-old mother of two, was killed after she was partially pulled out of the plane’s window when the engine exploded. Passengers had pulled her back into the plane and attempted to resuscitate her, but she was pronounced dead at a Philadelphia hospital.

The Philadelphia medical examiner ruled the cause of death to be from blunt impact trauma to her head, neck and torso. Seven others suffered minor injuries.

After they landed, Shults walked back to check on the passengers and the flight attendants.

“My mother had told me, ‘If I’m flying, I want to know what’s going on.’ So I thought I would treat them like I would treat my own family,” she said.

Shults said she texted her family, including her 18-year-son, also a licensed pilot, when she landed.

“When I told [him] that I’d landed single engine in Philly safe on the ground, his immediate text back was, ‘That’s why Southwest gives you two,’ ” she said.

Shults said she was never worried about landing the plane safely.

“As long as you have altitude and ideas, you’re okay,” Shults said. “And we had both.”