Passenger use of electronic devices cause compass error which, in turn, causes navigation error.

Attributes
ACN	236197
Time
Date	199303
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : mck
State Reference	NE
Altitude	msl bound lower : 31000 msl bound upper : 31000
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Route In Use	enroute airway : j44
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : flight engineer pilot : atp pilot : commercial
Experience	flight time last 90 days : 200 flight time total : 12000 flight time type : 4000
ASRS Report	236197
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

While tracking the centerline of J-44 en route to mccook VOR, ZDV called and gave us a vector heading 10 degrees to the left because we were 7 NM south of the airway. A quick check of the cockpit instruments revealed that the #1 compass was 10 to 15 degrees in error. Several attempts were made to realign the compass with no success. I then asked the first flight attendant to check the passenger cabin for passenger operated electronic devices. She reported that a laptop computer with an external battery pack was in operation over the right wing. Plus a video game and a calculator in operation in other parts of the cabin. I then asked the passenger to secure all electronic equipment via a PA announcement. After all electronic equipment was turned off, the #1 compass returned to normal operation and remained normal for the remainder of the flight. I believe that the passenger operated electronic devices were adversely disrupting the navigation equipment of the aircraft. I respectfully suggest that the recommendations contained in the FAA advisory circular letter 91-21 concerning passenger operated electronic devices in aircraft be implemented on my airline as soon as possible.

Original NASA ASRS Text

Title: PAX USE OF ELECTRONIC DEVICES CAUSE COMPASS ERROR WHICH, IN TURN, CAUSES NAV ERROR.

Narrative: WHILE TRACKING THE CTRLINE OF J-44 ENRTE TO MCCOOK VOR, ZDV CALLED AND GAVE US A VECTOR HDG 10 DEGS TO THE L BECAUSE WE WERE 7 NM S OF THE AIRWAY. A QUICK CHK OF THE COCKPIT INSTS REVEALED THAT THE #1 COMPASS WAS 10 TO 15 DEGS IN ERROR. SEVERAL ATTEMPTS WERE MADE TO REALIGN THE COMPASS WITH NO SUCCESS. I THEN ASKED THE FIRST FLT ATTENDANT TO CHK THE PAX CABIN FOR PAX OPERATED ELECTRONIC DEVICES. SHE RPTED THAT A LAPTOP COMPUTER WITH AN EXTERNAL BATTERY PACK WAS IN OP OVER THE R WING. PLUS A VIDEO GAME AND A CALCULATOR IN OP IN OTHER PARTS OF THE CABIN. I THEN ASKED THE PAX TO SECURE ALL ELECTRONIC EQUIP VIA A PA ANNOUNCEMENT. AFTER ALL ELECTRONIC EQUIP WAS TURNED OFF, THE #1 COMPASS RETURNED TO NORMAL OP AND REMAINED NORMAL FOR THE REMAINDER OF THE FLT. I BELIEVE THAT THE PAX OPERATED ELECTRONIC DEVICES WERE ADVERSELY DISRUPTING THE NAV EQUIP OF THE ACFT. I RESPECTFULLY SUGGEST THAT THE RECOMMENDATIONS CONTAINED IN THE FAA ADVISORY CIRCULAR LETTER 91-21 CONCERNING PAX OPERATED ELECTRONIC DEVICES IN ACFT BE IMPLEMENTED ON MY AIRLINE AS SOON AS POSSIBLE.

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.