A growing demand for workers trained in science, technology, engineering and mathematics (STEM) in the U.S. has companies looking for alternative ways to secure their work forces. 

Nearly 30 percent of industry workers are 50 to 59 years old.  An anticipated wave of retirements in those industries has companies concerned about finding and retaining qualified workers in the U.S.  

Some businesses are taking measures to increase their efforts by partnering with schools, calling for higher national education standards, and sponsoring more student competitions, according to Reuters and a special report from Aviation Week. 

"It's not so much that the source of supply is not there,"  said the CEO of avionics maker Rockwell Collins Inc., Clay Jones. "It's that the source of supply in the United States may not be there."

Chief Executive of Raytheon Co, William Swanson said that the shortage could pose a national security danger because it can limit the ability of the United States to be innovative and compete on the world stage.

"If we can work on retention and we can work on the excitement of STEM or engineering, then we can change the equation," said Swanson.

And while many engineering jobs in these fields are only open to U.S. citizens because of security requirements, some aerospace and defense companies say they will recruit more workers from outside of the states recruiting in STEM-strong countries like China and India if necessary.

"I have a lot of positions, but a lot of times I may not be able to fill them because I don't have U.S. citizens," said Executive Director of Career Services at Embry-Riddle Aeronautical University, Lisa Kollar.   

According to the Aviation Week report, five percent of U.S. bachelor's degrees are in engineering, compared with 20 percent in Asia.

The report found that, 19 percent of employees among companies with more than 100,000 workers are now at retirement age. That figure is expected to jump to more than 30 percent in 2012 and nearly 40 percent by 2014.