I still have a hard time believing it was a compass that was affected by a laptop computer. ADF indication, could be. VOR, maybe. Magnetic compass? I wouldn't want a magnetic source that strong in my lap! My belt buckle would be stuck to it. There is quite a distance between a magnetic compass in the cockpit of an airliner and anything a passenger is carrying. Not so in a Cessna 172, but in a DC-10? Ghery Pettit -----Original Message----- From: James Collum [mailto:james.col...@usa.alcatel.com] Sent: Thursday, January 03, 2002 10:47 AM To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues
********* A routine flight over Dallas-Fort Worth was disrupted when one of the compasses suddenly shifted 10 degrees to the right. The pilot asked if any passenger was operating an electronic device, and finding that a laptop computer had just been turned on requested that it be turned off, whereupon the compass returned to normal. Following RTCA guidelines the pilot requested that the laptop be turned on again 10 minutes later, when the compass error returned. Ref: Compliance Engineering (European edition) Nov/Dec 1996 p12 ********* I am fascinated by this amazing story (which must surely be an urban myth) and went in search of more info on the internet. I had never heard of the RTCA ( a private corporation) before, but noticed via their web site that you have to be a member company (i.e. pay) to receive the wisdom that it contains. Aviation is merely a hobby of mine but I'm interested in reading a copy of the RTCA's DO-233/214 and 196 documents without shelling out hundreds for the privilege, can anyone advise? Also does anyone know what recommendations have they made to modifying FAR 91.21 (as per their web site). In reading this again, I'm curious as to how the pilot would have known about a private companies convoluted guideline for fault finding on errant radio direction equipment involving locating industrious passengers and commandeering their computers at 10 minute intervals. Surely he would have done what any professional engineer would do, beat or kick the 10 degree error out of the RDF equipment? Or maybe just wonder to him/herself about how strange things happen in the Dallas Fort Worth area? Tounge in cheek, my comments and not those of my employer etc. Jim
