Greg Allan: The Cable Guy to the Rescue

NASA and businesses call him to troubleshoot wiring mysteries

6 June 2008
Allan with the instrument he used to diagnose faulty fuel sensors for NASA.

When NASA scrapped two Atlantis shuttle launches in December because of faulty fuel sensors, IEEE Member Greg Allan was the guy on speed dial.

Arriving at the Kennedy Space Center in Florida, Allan diagnosed the problem with a portable time domain reflectometer (TDR), a device that sends a high-frequency pulse down a cable, captures the electromagnetic reflections, and analyzes the waveform to determine the nature and location of a fault.

“The shuttle fuel sensors are like gas gauges in your car,” he says. “When the tanks were filled with liquid nitrogen, everything was okay for 10 minutes before the sensors suddenly registered empty. The TDR trace registered an open circuit at a connector where wiring passed from outside to inside the tanks.”

It turned out that the sensor manufacturer had made a change in the design it thought wasn’t significant. NASA solved the problem by hard-wiring the sensors to bypass the connector.

The news of Allan’s help in solving the problem made the local newspapers in his quiet Pittsburgh suburb. “It was one of the first few occasions when my kids were able to understand what I do,” he says.

Allan, 45, is technical director for CM Technologies, in Coraopolis, Pa., a manufacturer of instruments that help diagnose problems in electrical cable wiring. NASA is its most high-profile client, but CM also services some 30 to 40 nuclear power plants, as well as military and commercial aircraft and Navy submarines.

KEEPING UP TO DATE “Wiring problems are our specialty,” Allan says. “Our expertise is providing instrumentation and services to diagnose problems in wiring and electrical cable.” While TDR technology has been around since the 1950s, CM Technologies recently carved out a niche with proprietary credit card–size devices that plug into computers and PDAs, giving them TDR capability—which allows for testing, troubleshooting, and waveform interpretation.

CM has sold units to the Johnson Space Center, in Houston, for the space station; to a doctor in India researching waveform differences in healthy and cancerous cells; to Colgate-Palmolive for research in diagnosing problems in teeth; and to geologists monitoring earth movements in mines. On the services side, Allan helped investigate the 2006 Con Edison Indian Point power plant shutdown in New York that caused a blackout in Manhattan.

“The high-profile things are interesting in that you’re able to say, ‘Hey, I was there,’” he says. “But ultimately it’s about solving a puzzle—and the thrill of being correct.”

Allan grew up in Venetia, Pa., and got his first taste of computer programming on the Radio Shack TRS-80 in high school. He initially intended to become a software programmer when he entered Ohio Northern University, in Ada, until a growing interest in his lab work lured him to engineering. He earned a bachelor’s degree in electrical engineering in 1985.

“In college, we were encouraged to join IEEE as a way of  becoming aware of what’s going on in industry, and being a member indicates on job interviews that you’re serious about engineering as a career,” he says.

He continues to be a member to keep his skills current through self-study courses, society membership, and publications, he says.

AIR FORCE ROOTS He began his career as a civilian electronics engineer for the U.S. Air Force, writing programs for testing avionics equipment and at the same time earning a master’s degree in electrical engineering from Mercer University, in Macon, Ga. He joined CM Technologies in 1991.

The company was born in 1984 when founder Sheldon Lefkowitz, a mechanical engineer, was hired to investigate a power failure at the San Onofre Nuclear Generating Station near San Clemente, Calif. Lefkowitz found that the insulation surrounding an electrical cable routed near a steam pipe had eroded; the cable had touched the pipe and caused a short circuit. As part of a return-to-service agreement, the plant implemented a cable-monitoring program and put Lefkowitz and his staff on retainer.

The aviation industry tapped the firm’s expertise after two high-profile commercial airline crashes jolted the Federal Aviation Administration, NASA, and the U.S. military into addressing old wiring.

In 1996, TWA Flight 800 exploded en route from New York to Paris, killing all 230 aboard when a frayed wire touching the fuselage caused a short circuit. Two years later, deteriorating in-flight entertainment-system wires caused a fire on Swiss Air Flight 111, which crashed off the coast of Nova Scotia, killing 229.

“Until that point, wiring in commercial aviation had been ignored,” Allan says. “Companies are often not set up to maintain these things.

“Nuclear utilities are our biggest customers because they have required maintenance programs. Let’s face it—if a pump in a cookie plant fails, it’s not going to have the same repercussions.”

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