Private eye in the sky? Government eavesdropping? Nope. It's just Daryl Rosenberger, along with another pilot, checking for leaks.
Cable TV leaks, that is.
All cable systems, whether giants like Comcast, Time Warner and Cox or small mom-and-pop outfits, transmit programming to their customers over cables; the electronic signal flowing through the wires has the same frequency range (108 megahertz to 137 megahertz) that commercial planes use to communicate with ground control and other aircraft.
Typically, there's no problem. However, if enough cables are cracked or street-side connections are poor, the cable signal literally spews into the atmosphere. In sufficient quantities, cable leakage can disrupt aviation-related communications.
The problem wasn't recognized until 1976, when a commercial jet approaching the Harrisburg, Pa., airport lost communication contact with the airport's control tower. The jet landed safely, but a subsequent investigation found that leaks from the local cable TV operator's system had caused the problem.
Alarmed, the Federal Aviation Administration first wanted to prohibit cable operators from using the same frequency as the nation's commercial aviation system. But that would have severely limited the number of channels cable companies could offer.
A Federal Communications Commission task force took on the problem, assigning the scientific review to a young engineer named John Wong, who'd only recently joined the agency. "I cut my teeth on cable signal leakage," says Wong, who's now chief engineer of the FCC's Media Bureau.
After two years of study and trial-and-error experiments looking for fixes, Wong and his colleagues produced the plan that's in use today. Wong's solution allows cable operators to continue using the same frequency as the aviation system but requires them to conduct an annual cable leakage audit and file a lengthy, detailed report with the FCC.
In 1988, 12 years after the Harrisburg incident and the year before the new cable leakage requirements went into effect, Rosenberger, a graduate of University of Florida's College of Engineering, heard of the proposal and saw a business opportunity.
An engineer with BellSouth, Rosenberger reasoned that cable operators would farm out the job of testing for cable leaks because it would be cheaper to use an outside vendor and because the reports would carry the stamp of a third-party auditor. And so Rosenberger went into business as Mar-Tech Engineering, based in Jacksonville.
Finding a niche
After starting with one Cessna 310 airplane and accounts in Yulee and Brunswick, Ga., Mar-Tech now has seven planes, 14 employees and accounts all across the country. "In Florida -- virtually any city with a population of over 30,000, we test it," says Rosenberger, 46.
Mar-Tech, in fact, is the biggest of the few cable leakage detection companies in the country, though its size still makes it "a small little niche business," Rosenberger says. Mar-Tech doesn't release sales or profit figures, but the entire industry is thought to generate no more than $5 million in annual revenue.
Cable leakage audits can be conducted on the ground using vehicles equipped with special monitors. However, it is more cost-effective to conduct the tests from the air, where a plane with monitoring devices can cover wider areas much quicker.
To test a cable system, Rosenberger replaces the signal for one channel, typically one of the least watched, with another special frequency that the monitoring equipment on the plane can detect if it's leaking into the atmosphere.
A Mar-Tech plane flies over the cable franchise area, and onboard computers pick up leakage and record its location. All the data are then compiled in a report, along with a map showing the strength of the leaks and where they were detected.
Business has changed since Sept. 11. Mar-Tech now has to get special waivers to fly over cities such as New York, Boston and Washington, D.C. The company's pilots undergo background checks, and armed law enforcement agents fly on flights over Washington. Flights over the White House are still off-limits.
Signal-tight
Mar-Tech is now looking to expand its service to Ireland and other European countries. While those governments don't require cable operators to audit for cable leaks, cable companies recognize that a signal-tight system is good business, especially as cable becomes more interactive.
When Rosenberger started Mar-Tech 15 years ago, 15% to 20% of the cable systems tested for signal leakage failed. Today, less than 1% fail. "Standards really have improved as cable has had to compete," Rosenberger says.
The FCC still vigilantly enforces the leakage standards and can fine and even shut down violators until they correct a problem. Just last year the FCC fined a small cable operation in Mississippi $130,000 for being too leaky. "The program has shown how industry and government worked together to prevent a train wreck," says Wong. "The fact that most people don't know about cable leakage is a testament to how effective it's been."