Narrative:

The lead flight attendant reported a cell phone in use on the ground at the gate. Later, while at cruise, the #1 navigation receiver was noted to be behaving abnormally. The to/from flag would partially retract after initial deployment on any frequency, but would work fine in the 'from' mode. The anomaly ceased after we had descended through FL180 (the altitude at which the flight attendants make the descent passenger electronic device announcement) and worked fine through the approach and at the gate on the vot. We wrote it up in the logbook as a suspected passenger electronic device interference incident and a VOR sensitivity check was performed on the #1 navigation receiver, which was satisfactory. Since the lead flight attendant's passenger electronic device walk had not turned up anything else of note, I suspect that the passenger had left his cell phone switched on in-flight and that this may have contributed to our navigation receiver problem. P.south. Our airline recently changed its passenger electronic device policy to permit cell phone operation on the ground with the door open. I have experience, like this incident, which leads me to believe that such a policy may not be wise.

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Original NASA ASRS Text

Title: DC9 CREW SUSPECTS PAX CELL PHONE INTERFERING WITH NAV RECEIVER DURING FLT IN ZHU AIRSPACE.

Narrative: THE LEAD FLT ATTENDANT RPTED A CELL PHONE IN USE ON THE GND AT THE GATE. LATER, WHILE AT CRUISE, THE #1 NAV RECEIVER WAS NOTED TO BE BEHAVING ABNORMALLY. THE TO/FROM FLAG WOULD PARTIALLY RETRACT AFTER INITIAL DEPLOYMENT ON ANY FREQ, BUT WOULD WORK FINE IN THE 'FROM' MODE. THE ANOMALY CEASED AFTER WE HAD DSNDED THROUGH FL180 (THE ALT AT WHICH THE FLT ATTENDANTS MAKE THE DSCNT PAX ELECTRONIC DEVICE ANNOUNCEMENT) AND WORKED FINE THROUGH THE APCH AND AT THE GATE ON THE VOT. WE WROTE IT UP IN THE LOGBOOK AS A SUSPECTED PAX ELECTRONIC DEVICE INTERFERENCE INCIDENT AND A VOR SENSITIVITY CHK WAS PERFORMED ON THE #1 NAV RECEIVER, WHICH WAS SATISFACTORY. SINCE THE LEAD FLT ATTENDANT'S PAX ELECTRONIC DEVICE WALK HAD NOT TURNED UP ANYTHING ELSE OF NOTE, I SUSPECT THAT THE PAX HAD LEFT HIS CELL PHONE SWITCHED ON INFLT AND THAT THIS MAY HAVE CONTRIBUTED TO OUR NAV RECEIVER PROB. P.S. OUR AIRLINE RECENTLY CHANGED ITS PAX ELECTRONIC DEVICE POLICY TO PERMIT CELL PHONE OP ON THE GND WITH THE DOOR OPEN. I HAVE EXPERIENCE, LIKE THIS INCIDENT, WHICH LEADS ME TO BELIEVE THAT SUCH A POLICY MAY NOT BE WISE.

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.