Passenger electronic devices twice interfered with aircraft systems and navigation equipment.

Attributes
ACN	100669
Time
Date	198812
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : ewn
State Reference	NC
Altitude	msl bound lower : 13000 msl bound upper : 13000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Transport, High Wing, 2 Turboprop Eng
Navigation In Use	Other
Flight Phase	cruise other other
Route In Use	enroute airway : zdc
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 200 flight time total : 5000 flight time type : 1000
ASRS Report	100669
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : overcame equipment problem other
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

Due to bad WX we went into holding at 13000' at beula intersection in IFR conditions. While in holding both autoplt and yaw dampers disengaged. In addition we lost both flight guidance computers and air data computers. At the same time the F/a called up and informed me that a passenger in row I was using some sort of transceiver and was using it to either communication or receive WX information on a HF marine band frequency. I told the first officer to make sure the man immediately put the radio away--that it was interfering with the aircraft. About a minute after I got the computers on line, the entire event recurred, including a call from the flight attendant/ about the man in row I. This time I sent the first officer back to make sure the radio was put away. When he came back to the cockpit, he informed me that his man had a bag of various electronic devices. I also informed ZDC of our problem and that I was uncertain of our exact position and the reliability of our radios due to the interference (or possible interference). We got all the computers back to normal operation, but because of bad WX we diverted to kinston, nc, west/O incident. Unfortunately I never did get to see the man or the radios he was using. My first officer claims one of them was a high frequency marine band radio. Even though we broke no regulations, I think it presents a potentially dangerous situation, and that all mdt crews, or all crews need to be aware of. First, radio interference does effect the mdt aircraft and these crews do need to be aware of this. I don't know if it was a combination of this man sitting in row I near the VHF communication antennas, and the ahrs computers under the floor, or just having enough wattage, or magnetism to throw the computer slightly out of line or what. Secondly, people are told mistakenly by airlines, radio manufacturers and salesmen that their radios are approved for aircraft use by the FAA/FCC when in fact they are not. Third, maybe airlines need to re-emphasize that no radio transceiving devices are allowed for use on aircraft. Just imagine if the man had successfully penetrated a fly by wire aircraft. I should also note that I flew this aircraft prior to and following this incident with no problems.

Original NASA ASRS Text

Title: PASSENGER ELECTRONIC DEVICES TWICE INTERFERED WITH ACFT SYSTEMS AND NAVIGATION EQUIPMENT.

Narrative: DUE TO BAD WX WE WENT INTO HOLDING AT 13000' AT BEULA INTXN IN IFR CONDITIONS. WHILE IN HOLDING BOTH AUTOPLT AND YAW DAMPERS DISENGAGED. IN ADDITION WE LOST BOTH FLT GUIDANCE COMPUTERS AND AIR DATA COMPUTERS. AT THE SAME TIME THE F/A CALLED UP AND INFORMED ME THAT A PAX IN ROW I WAS USING SOME SORT OF TRANSCEIVER AND WAS USING IT TO EITHER COM OR RECEIVE WX INFO ON A HF MARINE BAND FREQ. I TOLD THE F/O TO MAKE SURE THE MAN IMMEDIATELY PUT THE RADIO AWAY--THAT IT WAS INTERFERING WITH THE ACFT. ABOUT A MINUTE AFTER I GOT THE COMPUTERS ON LINE, THE ENTIRE EVENT RECURRED, INCLUDING A CALL FROM THE FA/ ABOUT THE MAN IN ROW I. THIS TIME I SENT THE F/O BACK TO MAKE SURE THE RADIO WAS PUT AWAY. WHEN HE CAME BACK TO THE COCKPIT, HE INFORMED ME THAT HIS MAN HAD A BAG OF VARIOUS ELECTRONIC DEVICES. I ALSO INFORMED ZDC OF OUR PROB AND THAT I WAS UNCERTAIN OF OUR EXACT POS AND THE RELIABILITY OF OUR RADIOS DUE TO THE INTERFERENCE (OR POSSIBLE INTERFERENCE). WE GOT ALL THE COMPUTERS BACK TO NORMAL OPERATION, BUT BECAUSE OF BAD WX WE DIVERTED TO KINSTON, NC, W/O INCIDENT. UNFORTUNATELY I NEVER DID GET TO SEE THE MAN OR THE RADIOS HE WAS USING. MY F/O CLAIMS ONE OF THEM WAS A HIGH FREQ MARINE BAND RADIO. EVEN THOUGH WE BROKE NO REGS, I THINK IT PRESENTS A POTENTIALLY DANGEROUS SITUATION, AND THAT ALL MDT CREWS, OR ALL CREWS NEED TO BE AWARE OF. FIRST, RADIO INTERFERENCE DOES EFFECT THE MDT ACFT AND THESE CREWS DO NEED TO BE AWARE OF THIS. I DON'T KNOW IF IT WAS A COMBINATION OF THIS MAN SITTING IN ROW I NEAR THE VHF COM ANTENNAS, AND THE AHRS COMPUTERS UNDER THE FLOOR, OR JUST HAVING ENOUGH WATTAGE, OR MAGNETISM TO THROW THE COMPUTER SLIGHTLY OUT OF LINE OR WHAT. SECONDLY, PEOPLE ARE TOLD MISTAKENLY BY AIRLINES, RADIO MANUFACTURERS AND SALESMEN THAT THEIR RADIOS ARE APPROVED FOR ACFT USE BY THE FAA/FCC WHEN IN FACT THEY ARE NOT. THIRD, MAYBE AIRLINES NEED TO RE-EMPHASIZE THAT NO RADIO TRANSCEIVING DEVICES ARE ALLOWED FOR USE ON ACFT. JUST IMAGINE IF THE MAN HAD SUCCESSFULLY PENETRATED A FLY BY WIRE ACFT. I SHOULD ALSO NOTE THAT I FLEW THIS ACFT PRIOR TO AND FOLLOWING THIS INCIDENT WITH NO PROBS.

Data retrieved from NASA's ASRS site as of August 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.