Pilots awaiting instructions on where to taxi at Logan International Airport were startled one day in June when they switched their radios to the frequency reserved for air traffic control, only to hear the cockpit flooded with "foreign language music" and unfamiliar broadcasts that had nothing to do with flying.
Agents in a car fitted with high-tech equipment followed the signal to a three-story, green-shingled house in Brockton, where they found an unlicensed radio station - commonly referred to in the industry as "pirate radio" - operating in the basement, according to records unsealed in federal court this week.
The radio interference "created a serious safety issue" by preventing air traffic controllers from communicating with private aircraft, but not commercial airlines, on the frequency published to all pilots, according to an affidavit filed in court.
"There is always a risk that the change would not be communicated to pilots, creating a dangerous situation," wrote Edward Kelly, a Federal Communications Commission agent, in his affidavit to the court.
In his initial visit to the Brockton home at 65 Richmond St. on June 18, Kelly recounted that he found a radio transmitter operating unattended, turned it off, and left a note on his business card warning the operator not to turn it back on because it was interfering with an FAA frequency and was operating illegally.
After two days of inactivity, Kelly said, the station began broadcasting again on June 21. A federal judge promptly granted a request by US Attorney Michael J. Sullivan's office to seize the radio transmitter, an antenna on the roof of the house, and other equipment.
Though court records don't identify the suspected owner of the radio equipment, a judge ordered the court to notify Natacha Souffrant, who lives at the Richmond Street address, and Cedor Souffrant of Randolph of their right to challenge the forfeiture of the equipment.
The Souffrants couldn't be reached for comment yesterday. A young man who answered the door at a first-floor apartment in the building Tuesday told a reporter that he didn't know anything about the basement radio station.
Michael C. Keith, a Boston College professor who teaches a course on the role of radio in American culture and has authored numerous books on the subject, said there are hundreds of pirate radio stations throughout the country and probably a dozen in the Boston area.
"They're mostly hobbyists or people who feel disenfranchised from mainstream radio," said Keith. The stations often broadcast for a couple of hours a day so the operators and their friends can hear music they don't hear over traditional airwaves.
Keith said most unlicensed radio operators don't stray onto FAA frequencies. As for those who do, Keith said, "it's a consequence of their amateurishness."
But he said their numbers have diminished over the past decade as the FCC adopted new licensing regulations to try to legitimize low-powered stations and as more people turned to the Internet as a less expensive and legal way to broadcast their message.
There have been a handful of cases involving pirate radio stations interfering with air traffic controllers, including one in Miami last year, and one that caused severe interference and disrupted flights in Israel a few months ago, according to press reports.
Jim Peters, a spokesman for the FAA's New England region, said he couldn't recall any other cases in New England involving complaints about unlicensed radio operators interfering with flight communications between pilots and air traffic controllers. But he said any interference is serious.
"Any time there's a communication between a pilot and a controller, we want to make sure each party hears clearly what each party is saying," Peters said. "The reason for that is to make sure that everyone understands the directions that are being issued and received."
An FCC spokeswoman declined to comment. The FCC's website indicates that the agency routinely orders unlicensed radio station operators to stop broadcasting and occasionally moves to seize their equipment. Earlier this year, it sent warning notices to unlicensed radio operators in Dorchester, an unidentified section of Boston, Dedham, and another Brockton location.
In July, a Randolph man agreed to pay $10,000 to settle a civil complaint filed by US Attorney Michael J. Sullivan's office, demanding that he forfeit some of his assets to the government after being caught operating an illegal radio station out of his home, according to court records.