Jeff Platt tapped out a few instructions on his computer, awakening the robotic arm in his Medford office.

Jeff Platt tapped out a few instructions on his computer, awakening the robotic arm in his Medford office.

"Stand back," warned the computer software engineer as the remote control robot armed with a laser beam began to move.

With a whirring sound and a few audible clicks, it suddenly rotated its head and directed the red laser beam to focus on a small X on the wall where a visitor stood a second earlier.

"I was just calibrating the right number of degrees for gear ratio," he explained.

The robot is a prototype miniature of larger remote control robotic arms the Medford-based Jetray Corp. builds for automated nondestructive testing of aircraft, using X-rays and other sensors to detect hairline cracks in a plane's fuselage.

"Like what happened on Southwest, that's what we detect — the classic lap seam failure that's due to corrosion or fatigue," said Mike Sorensen, 46, a business partner of Platt's and a mechanical engineer who focuses on the physical design.

He was referring to a 5-foot tear in the aluminum roof of a Southwest Airlines Co. jet as it cruised 34,000 feet above Arizona on Friday. The Boeing 737-300 landed safely, but the incident caused the grounding of dozens of planes and the cancellation of hundreds of flights as airlines launched safety inspections.

Ever since an 18-foot section of an Aloha Airlines jet peeled off in 1988, killing a flight attendant, metal fatigue has been an aviation concern. Jetray began working on nondestructive testing systems in 2001, Sorensen said.

"The Southwest Airlines 737 lap seam failure is a fatigue or corrosion issue we have been able to detect for years," Sorensen said.

Jetray is a spinoff company of Ravensclaw Inc., also based in the same Medford facility. In fact, Sorensen and his co-workers have received seven Academy Awards for scientific and technical achievement for their work in remote control camera systems in such movies as "Titanic," "Men in Black" and "Volcano." Platt, 54, has developed a half-dozen software systems for the firm to operate the remote cameras.

The equipment is built in Medford and shipped to Los Angeles, where most of the robotic equipment is used in the motion picture business. About eight people work out of the Medford shop.

"For the film industry, we build remote camera heads and lens control systems," Sorensen said. "That's our bread and butter."

Actually, Platt has roots in Hollywood. He happens to be the spitting image of his father, Edward Platt, the chief in the 1960s TV series "Get Smart." He does an excellent rendition of the angry chief when he yells "Max!"

"My dad told me there were too many good actors out of work," he said, explaining his decision to become a software engineer.

In addition to perfecting remote control camera systems, the firm also is working on the newest field-portable satellite dishes for General Dynamics, Sorensen said.

"In the motion control business, it's kind of difficult to have a steady income stream in one field," he said. "Jetray was born out of necessity. I got a call from General Electric, Northrop Grumman and from Delta pretty much in the same week, all unassociated. There was a bunch of nondestructive testing of aircraft needed at the time."

When GE called Sorensen a dozen years ago, it had just created a high-resolution digital X-ray device with a panel that detects cracks and corrosion on an aircraft, he said. What the firm didn't have was sophisticated robotic technology capable of deploying the sensor, he added.

"They had this panel worth just half a million dollars that was basically duct-taped to the side of the aircraft and no way to move it around," he said. "And you are talking about thousands of square feet of aluminum surface on a large aircraft.

"Robotically, we are able to drive it around and put it on the air frame anywhere it needs to be," he said. "We can cover about 85 percent of the pressure vessel and archive all that data."

The sensors Jetray now employs, including thermography, heat and ultrasound as well as X-ray, can reveal corrosion material loss down to 2,000th of an inch and crack migration of about 1/4-inch long, Sorensen said.

"We take three pictures of each location, shifting the camera at each location to basically create a pseudo 3-D image," he said, noting a tiny crack is difficult to see in an X-ray when seen from only one vantage point.

However, despite the firm's focus on aircraft metal fatigue, Sorensen is quick to observe he feels very safe flying in a commercial aircraft.

"I have no concerns about flying from a mechanical standpoint," he said. "It's unbelievable the amount of work they do on these aircraft to keep them safe."