Aerospace struggles to replace generation of engineers.

When Rich Allen retires this summer as director of engineering operations for Northrop Grumman Corp.'s Space Technology branch, the graying engineer will walk out the door with four decades of hands-on experience.

To prevent that experience from being lost forever, Allen has a bench of experienced managers being groomed to take his place.

"Each senior position has one--they're in their late 40s and early 50s," said Allen, 61, who expects to return after retiring to work part time mentoring and teaching.

Northrop is at the center of a looming problem facing all industries: a generation of baby-boomers nearing retirement whose departure from the workforce will leave significant gaps, given the smaller number of younger replacements.

The problem is acute in aerospace, which saw a big influx of workers in the 1960s as the country raced to send a man to the moon and the Vietnam War pumped up defense spending, hiring and salaries.

It also comes as defense spending, prompted by the Iraq War and efforts to combat terrorism, is up significantly for the first time since the end of the Cold War.

"This has been something on our list of top 10 issues for several years," said Matt Grimison, spokesman for the Aerospace Industries Association. "It crept up. Everyone had it in the back of their mind that it would be a problem. In the last two or three years, we realized it needs immediate action."

In 1990, the aerospace industry employed 1.1 million workers nationwide. But after more than a decade of defense cuts, employment reached a 50-year low in 2004, at 568,700. Many of the workers laid off were in the second half of the careers, the kind of people with 10 to 15 years of experience who could've replaced retiring engineers such as Allen.

The cuts also came just as the dot-com boom drew away many electronic engineers and software and network developers. Aerospace wasn't considered a hot field several years ago, so enrollment in university aerospace programs declined.

"When I was a student in the '80s, we had 100 to 150 students every year," said Marietta Penoliar, now an academic advisor at USC's School of Mechanical and Aerospace Engineering. "Now we're graduating 20 to 25 students a year."

Northrop estimates that 40 percent of its 125,000 employees will be eligible to retire in the next four years. The company, like others in the aerospace industry, has a "knowledge management" program in which engineers near retirement are interviewed about their job and also serve as mentors. Northrop executives also sit on the boards at the engineering schools of UCLA, USC and California State University, Northridge.

The company also has been relying more heavily on retired engineers, who come back to work on a part-time basis for specific projects.

Chicago-based Boeing Co., which employs 34,000 in Southern California, gave $22 million in grants to schools nationwide to beef up science and technology curricula from the elementary to the university level. It also offers secondary school internships.

To the moon

Meanwhile, Northrop, Boeing and other companies are lobbying state lawmakers to build support for a new bill, the Career Technical Education Accountability Act of 2005, which would enforce previously made commitments to improve technical career training in high schools.

For all those efforts, the companies say their biggest boost may come from a recently announced plan by President Bush to conduct manned space flights to the moon and eventually to Mars - the kind of inspiration that the space shuttle has not offered.

"It's very important, mostly for the folks just coming out of school," said Dick Croxall, 61, vice president of mission assurance at Northrop Space Technology, who is retiring this year. His career began in 1967.

If the initiative gains traction, it may give aerospace some of the appeal it had back in the 1960s as it competes with faster growing high-tech industries.

"The best and brightest are not choosing aerospace and defense jobs, so at the same time you're losing corporate knowledge, it's not being replaced with the best innovative thinking," said Jonathan Kutler, an aerospace investment banker with Jeffries Quarterdeck. "They're going to Silicon Valley and other industries that have a perception of being more cutting edge."

In his nearly 40 years at Northrop, Allen said he saw just a handful of major programs from start to launch. At the same time, his stepson, a software programmer at a videogame company--who would be qualified to work on satellite programs--watches products go from design to shelf in a year.