Narrative:

I experienced interference with VOR navigation reception. We found a passenger in seat xa, operating a 300 MHZ toshiba protege laptop computer. We had her discontinue use of the computer and normal reception was restored. I have had previous problems with toshiba computers that are used in row X. I will not limit the use of passenger electronic devices yet, however I now immediately check to see if a laptop is on when experiencing navigation problems. Callback conversation with reporter revealed the following information: the reporter stated that the same exact incident occurred on a different EMB120 at row X and with a toshiba laptop computer. That time, they were at mccalister VOR, when the VOR needles on the mfd (multifunction display) went crazy and were spinning in circles. In both cases, it was spinning in circles on both navigation 1 and navigation 2. The reporter guessed it was a laptop computer causing it and had the flight attendant check it out and had the person turn it off. After the VOR returned to normal, the reporter asked the flight attendant to have the passenger turn it back on to see what would happen, and the instruments resumed to almost a normal position, but it was 40 degrees off from ATC. He said row X is the first row behind the trailing edge of the wing, and speculates this may have something to do with the wing's wiring or an instrument under the wing. With this particular incident, he is 90 percent sure that the passenger did turn her computer back on afterwards, but they were almost on top of the new VOR, so he believes that's why it didn't interfere again with the navigation. The reporter speculates that perhaps the toshiba laptop computer and the VOR had the same or similar frequencies.

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Original NASA ASRS Text

Title: PLT RPT, EMB120. PAX LAPTOP COMPUTER AT ROW X POSSIBLY INTERFERED WITH VOR NAVIGATION. CAPT HAD PAX'S COMPUTER SHUT OFF, NORMAL NAVIGATION RESUMED.

Narrative: I EXPERIENCED INTERFERENCE WITH VOR NAVIGATION RECEPTION. WE FOUND A PAX IN SEAT XA, OPERATING A 300 MHZ TOSHIBA PROTEGE LAPTOP COMPUTER. WE HAD HER DISCONTINUE USE OF THE COMPUTER AND NORMAL RECEPTION WAS RESTORED. I HAVE HAD PREVIOUS PROBLEMS WITH TOSHIBA COMPUTERS THAT ARE USED IN ROW X. I WILL NOT LIMIT THE USE OF PAX ELECTRONIC DEVICES YET, HOWEVER I NOW IMMEDIATELY CHECK TO SEE IF A LAPTOP IS ON WHEN EXPERIENCING NAVIGATION PROBLEMS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THAT THE SAME EXACT INCIDENT OCCURRED ON A DIFFERENT EMB120 AT ROW X AND WITH A TOSHIBA LAPTOP COMPUTER. THAT TIME, THEY WERE AT MCCALISTER VOR, WHEN THE VOR NEEDLES ON THE MFD (MULTIFUNCTION DISPLAY) WENT CRAZY AND WERE SPINNING IN CIRCLES. IN BOTH CASES, IT WAS SPINNING IN CIRCLES ON BOTH NAV 1 AND NAV 2. THE RPTR GUESSED IT WAS A LAPTOP COMPUTER CAUSING IT AND HAD THE FLT ATTENDANT CHECK IT OUT AND HAD THE PERSON TURN IT OFF. AFTER THE VOR RETURNED TO NORMAL, THE RPTR ASKED THE FLT ATTENDANT TO HAVE THE PAX TURN IT BACK ON TO SEE WHAT WOULD HAPPEN, AND THE INSTRUMENTS RESUMED TO ALMOST A NORMAL POSITION, BUT IT WAS 40 DEGREES OFF FROM ATC. HE SAID ROW X IS THE FIRST ROW BEHIND THE TRAILING EDGE OF THE WING, AND SPECULATES THIS MAY HAVE SOMETHING TO DO WITH THE WING'S WIRING OR AN INSTRUMENT UNDER THE WING. WITH THIS PARTICULAR INCIDENT, HE IS 90 PERCENT SURE THAT THE PAX DID TURN HER COMPUTER BACK ON AFTERWARDS, BUT THEY WERE ALMOST ON TOP OF THE NEW VOR, SO HE BELIEVES THAT'S WHY IT DIDN'T INTERFERE AGAIN WITH THE NAVIGATION. THE RPTR SPECULATES THAT PERHAPS THE TOSHIBA LAPTOP COMPUTER AND THE VOR HAD THE SAME OR SIMILAR FREQUENCIES.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.