NEW YORK (NYTIMES) - About 20 minutes after takeoff on Tuesday (April 17), Captain Tammie Jo Shults was steering a Southwest Airlines plane toward cruising altitude, generally considered the safest part of a flight. But then the left engine exploded.

The blast hurled debris into the side of the plane. A passenger window shattered. The cabin depressurised. A woman was partly sucked outside the plane. Passengers panicked and flight attendants sprang into action.

In the cockpit, Capt Shults remained calm as she steadied the aircraft, Flight 1380.

"Southwest 1380 has an engine fire," Capt Shults radioed to air traffic controllers, not a hint of alarm in her voice. "Descending."

In an instant, Capt Shults found herself in a situation most pilots face only during training: having to land a plane after an engine goes out.

For the next 40 minutes, she displayed what one passenger later called "nerves of steel", manoeuvring the plane, which had been on its way from La Guardia Airport in New York to Dallas Love Field, toward Philadelphia for an emergency landing.

In the seats behind her, passengers sent goodbye text messages to loved ones, tightened oxygen masks around their faces and braced for impact.

Flight attendants frantically performed CPR on the critically injured passenger, who later died at a hospital.

But Capt Shults, 56, was in control. She learned to fly as one of the first female fighter pilots in the navy three decades ago, piloting the F/A-18 Hornet in an era when women were barred from combat missions.

"Can you have the medical meet us there on the runway," Capt Shults calmly told air traffic controllers in Philadelphia. "They said there's a hole and, uh, someone went out."

At 11.20am Eastern time, Capt Shults steered the plane, a two-engine Boeing 737, to a smooth landing on Runway 27L at Philadelphia International Airport. The left engine looked as if it had been ripped apart.

"This is a true American hero," Ms Diana McBride Self, a passenger, wrote in a Facebook post. "A huge thank you for her knowledge, guidance and bravery in a traumatic situation. God bless her and all the crew."

Another passenger, Mr Alfred Tumlinson, was more direct in his praise.

"She has nerves of steel," Mr Tumlinson told The Associated Press. "I'm going to send her a Christmas card - I'm going to tell you that - with a gift certificate for getting me on the ground. She was awesome."

While women still make up a small percentage of commercial pilots, Capt Shults took up flying when there were far fewer in the industry and when women were often told to find other careers.

In her junior year at MidAmerica Nazarene University in Olathe, Kansas, she attended an Air Force event and spotted a woman in a piloting class, she told an alumni publication.

She graduated from MidAmerica in 1983 with a bachelor's degree in biology and agri-business and then set off to join the military, the university said on Wednesday.

The air force would not accept her, she told the publication, but the navy would. She enrolled in navy flight school in Pensacola, Florida, in 1985 - the start of a decade of groundbreaking service.

"We can confirm that Lt Commander Shults was among the first cohort of women pilots to transition to tactical aircraft," the navy said in a statement on Wednesday.

She flew the F/A-18 Hornet, the twin-engine supersonic fighter jet and bomber.

After flight school, in 1989, she was assigned to Tactical Electronic Warfare Squadron 34 in Point Mugu, California. During the Gulf War, her squadron was led by the first female air commander in the Navy.

But despite her accomplishments, she came up against the limits placed on women in the military.

She left active service on March 31, 1993 - two days before the Navy asked the Clinton administration to open combat assignments to women.

She then spent about a year in reserves before leaving the military in 1994, reaching the rank of lieutenant commander.

Capt Shults later became a pilot with Southwest Airlines, as did her husband, Mr Dean M. Shults. Southwest Airlines declined to comment about her on Wednesday.

But her husband confirmed to the Associated Press that she was at the controls of the plane.

After her name started to appear in news reports on Tuesday, fellow female fighter pilots started to message one another about Capt Shults.

Ms Christine Westrich, who flew the F/A-18 in the Marine Corps in the late 1990s, said she was struck by her service.

"She is undoubtedly a pioneer, being a Hornet driver well before the combat exclusion law was lifted," Ms Westrich said in an interview. "She kicks ass in my book."