Come January, women will head three of the six largest US weapons makers, a sign that their clout in the male-dominated industry is growing.
But executives and experts say the trend may be short-lived unless more young women choose engineering careers and defense companies figure out how to keep them.
Marillyn Hewson and Phebe Novakovic move into the CEO offices at Lockheed Martin Corp and General Dynamics Corp respectively on Jan. 1, joining trailblazer Linda Hudson, who became the first woman to head a major U.S. defense firm in 2009 when she was named CEO of BAE Systems Plc's U.S unit.
The promotions put them in a small club of 19 female CEOs who head Xerox, Hewlett Packard and other Fortune 500 companies.
But Hudson, 62, said Hewson and Novakovic's new jobs shouldn't be taken as signals that defense companies are now paradigms of equal opportunity for women.
I will be more convinced the industry has made a dramatic shift when I see significant numbers of female executive leaders at all levels of management throughout the entire industry, Hudson said.
Women have been making slow but steady inroads in science, technology, engineering and math (STEM) fields, and accounted for 14 percent of working engineers in 2009, up from 1 percent in 1960, the Association of American University Women said.
And women are gaining more promotions in the second-tier of management at defense companies. Boeing Co this month appointed five women to senior posts, two heading reorganized defense divisions.
But the wave of female engineers and scientists entering the defense business has stalled or reversed. In 2010, women earned 18.4 percent of U.S. bachelor engineering degrees, down from a peak of nearly 21 percent in 2002 and unchanged from the 1980s, according to the National Science Foundation.
In computer science, women earned only 18.2 percent of degrees in 2010, down from nearly 28 percent a decade ago.
You're seeing women move up within corporations. You're seeing a lot more mentoring inside companies, said Karen Panetta, who teaches engineering at Tufts University and edits Women in Engineering magazine.
But the number of women going into technical engineering fields is a real problem.
Today, one in four female engineering graduates chooses a career in aerospace, a figure that has not changed in nearly a decade, said Carole Hedden, an editor at Aviation Week magazine and author of an annual report on industry employment.
At a recent women's leadership forum sponsored by Lockheed, Hewson warned that the long-term trend of women entering aerospace and defense is no longer assured.
Frankly, we can't take it for granted, she told more than 350 women at the event on Nov. 8, a day before the company's board elected her to succeed Bob Stevens as CEO of Lockheed, the Pentagon's biggest supplier and the world's largest arms maker. Women are losing ground.
RECRUITMENT AND RETENTION
Hewson, 58, knows how hard it can be to break through the glass ceiling. She took 18 different leadership posts at Lockheed and moved her family eight times to reach the top. Her promotion to CEO came abruptly this month, when Lockheed's board fired its first choice, Christopher Kubasik, after he admitted to an improper relationship with a subordinate.
Hewson's long journey explains why defense companies find it tough to retain female employees. As women reach their mid-30s, many switch fields or leave to raise families, especially if they don't see clear advancement opportunities, said Panetta.
Hedden said the departures often reflect frustration among women about the challenges of a male-dominated culture where they feel they must prove their competence over and over again.
They get tired of fighting all the time, Hedden said.
Hudson logged many firsts in her ascent: first female to take engineering drawing at her Florida high school; first woman manager at Ford Aerospace and Communications Corp; first female vice president of an operating company at Martin Marietta; and first female corporate officer and company president at General Dynamics.
Every senior level job I got, people presumed I was incompetent, she said in an earlier interview. Only after I managed to perform did I get the point across.
Women have made bigger gains in professions such as finance and information technology, where they account for 41 percent to 55 percent of the workforce, according to a U.S. Commerce Department study. But in the manufacturing, transportation and mining and gas industries, the female workforce remains relatively small.
Big defense companies are spending to attract young women. Northrop Grumman Corp, for example, invests millions of dollars a year to encourage female high school and college students to pursue science, technology, engineering and math careers, said Linda Mills, who heads the company's $8.4 billion Information Systems unit.
Such investments have helped big companies like Lockheed and Northrop hire a greater proportion of women than smaller firms, according to Aviation Week's study.
Without that investment, declining enrollment in these fields by young women will deprive us of the very resource we are looking to access, said Marion Blakey, president of the Aerospace Industries Association and former head of the Federal Aviation Administration.
Mills, 62, is herself a role model: In January she will move to a newly created job overseeing Northrop's overall operations as corporate vice president of operations. In her view, the industry must do better at pitching women on exciting prospects in robotics, unmanned vehicles and cyberspace - areas where hiring is likely to continue even as the overall U.S. defense budget declines.
The defense industry has other forces working against it. Panetta, the Tufts professor, said such fields as biomedical engineering appeal to women who want to work on societal issues. In contrast, women often don't see options in aerospace and defense beyond making bombs, she said.
Some universities are now linking engineering programs to music and other creative fields to increase appeal to women and other groups, Panetta said.
Role models are key to combating stereotypes of scientists and engineers as geeky or weird, Mills said, noting that such images have persisted since she entered the field decades ago.
Hewson said television shows like NCIS and Criminal Minds often portray female analysts as brilliant but quirky and odd, while female investigators are shown as beautiful and sexy.
Attracting girls to science and technology while they are still in middle school is especially important, Panetta said.
Image is everything, she said. The media play a huge role.
The image, and recruitment, should improve with three women heading defense businesses, said Ana Dutra, chief executive for leadership and talent consulting at Korn/Ferry International.
It's going to be a total game-changer, Dutra said. There is an inspiration factor. I bet that we're going to see many more women graduates reaching out to those companies and wanting to be part of them, Dutra said.
But today's younger women likely won't have the patience to slowly work their way up and wait until they are in their late 40s, 50s or 60s to hold powerful jobs, Dutra said.
Companies need to identify their high potential women much earlier and try to develop them faster, she said. Otherwise, they are probably going to move out to other sectors.