The moment stands out clearly in Captain Lori Cline's mind. She was preparing her airplane for a flight to West Virginia when a man boarded with his young daughter.

"She was maybe 8 years old, and I was showing her all the bells and whistles [in the cockpit] and turning everything on for her. Her eyes got about as big as silver dollars. Like any young child, she looked at her dad, and she said, 'Oh, Daddy! I want to be a pilot when I grow up.'

"He looked at her and said, 'Oh, you could never do this.'"

The man's words stopped Cline cold. Here was a little girl with a dream who was never going to receive any encouragement at home. Cline wondered how many other girls with aspirations to fly would have their dreams crushed in youth.

She recalled that when she was a child, the only female pilot she could read about was Amelia Earhart.

"And she got lost," says Cline. "I never thought she was a very good role model."

Cline began thinking about how valuable a book about women in aviation would be for little girls who needed role models.

Her musings led her to coauthor two books — Ladybirds and Ladybirds II — that explore the history of American women in aviation.

Cline's books trace the history of American women in aviation back to the first female balloonist more than 200 years ago.

While women pilots can now be found in the Concorde, military and commercial planes, and even in the Space Shuttle, Cline knows from research and personal experience that these achievements haven't come easy.

"People have this sense that women just suddenly became qualified to fly for the airlines in the early seventies," says Cline. "But ... women flew during World War II in just about every make and model of airplane that flew off our country's assembly lines."

Cline is speaking of the more than 1,000 American women who joined the Women Airforce Service Pilots (WASPs) during World War II. This group test-piloted aircraft and logged 60 million miles in the air, ferrying the planes to American servicemen who took them into battle. Thirty-eight women died in service.

But when the war ended, so did women's opportunities. Commercial airliners wanted to hire pilots who had served in the war, but because the women never received official military status from the U.S. government, they were passed over for jobs. It would take the women's movement in the early 1970s to break the sex barrier again.

Emily Howell Warner broke that barrier by becoming the first female pilot hired by a commercial airline.

Although she had originally sought a job at Frontier Airlines in 1968, her application wasn't accepted until January 1973. Ironically, some of Warner's students were hired before her. They just happened to be male.

Warner served as inspiration for both Blankenship and Cline. Cline was 13 when Warner got hired. "We had an airplane in my family when I grew up," says Cline. "So at the age of 13, I was already taking flying lessons and literally flying before I was even driving."

Although she didn't know of Warner's achievement, it would end up serving her well less than 10 years later. Cline was hired directly out of college with her airline of choice, Piedmont Airlines.

Blankenship also grew up with airplanes because her father was a captain with Eastern Airlines. But when she attended high school, there was no such thing as a female airline pilot.

"When I was in high school, I was going to become an interior design/home economics major, " recalls Blankenship. "When I was a freshman in college, I kept thinking, 'you know, flying might be a lot of fun to do.' So I started learning to fly and then I was actually a senior in college before they hired the first female airline pilot.

"When I heard that they hired Emily, just in the back of my mind I said, 'I wonder if I can do this?' So when I graduated from college, there were a couple of women airline pilots at the time, and that's when I said, 'Let's go for it.'"

Blankenship was hired by Piedmont Airlines in 1977.

Both she and Cline have served as captains for U.S. Airways for more than 10 years. Blankenship flies 757s and Cline flies the A320 Airbus.

Today, thanks to such strong role models, there are more than 2,500 women pilots and 700 female captains. While this is still less than 3% of the total airline pilot population, it is a foot in the door. And that foot is keeping open the door to future opportunities for little girls who dream of flying machines.