In my experience it is EXTREMELY unlikely that personal electronics could have disturbed ADF heading indication. The ADF sensor is an electrostatically shielded loop which is mounted typically on the belly of a transport class aircraft, well away from any passenger-conveyed intense sources of magnetic fields. The loop is very insensitive and requires quite a bit of magnetic field to respond and is completely insensitive to electric fields altogether. Further, no one would use ADF to line up an approach on a runway.
---------- From: Cortland Richmond <cortland.richm...@alcatel.com> To: Mike Hopkins <mhopk...@thermokeytek.com> Cc: cherryclo...@aol.com, emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues List-Post: emc-pstc@listserv.ieee.org Date: Wed, Jan 2, 2002, 5:26 PM If they meant "radio compass," that is a different can of monkeys. The radio compass was traditionally the indicator for the ADF set , pointing to the ground station, and was usually mounted so as to revolve in front of a scale which rotated with the aircraft's' magnetic heading. A noisy switching power supply could well interfere with a low-frequency receiver. But (in MY opinion) the Guide does not say enough about what actually happened. Cortland (My thoughts, not Alcatel's!) Mike Hopkins wrote: As already stated, the incident of the DC-10 has for years been used as an example of personal electronics (laptops) interfering with avionics. The only version I've ever heard (and the only one that makes sense) had to do with interference to an ILS receiver operating somewhere between 108MHz and 118MHz. I for one, don't believe in laptop computers interfering with a compass -- UNLESS -- the people reporting the story (and writing the guide?) used a "compass" as a way to relate to the general population that a laptop caused interference with an instrument that kept the airplane headed in the right direction -- probably assuming that most people would not be able to relate to an ILS or NAV receiver, but everyone knows what a compass is..... I remember the magazine article, which also reported on an electronically controlled wheelchair going out of control when an EMT keyed a mobile two-way radio in a nearby ambulance. (I might add, I've since heard several variations on that story as well -- wheelchair went over a cliff, wheelchair went around in circles, wheelchair dumped patient and took of by itself; radio was a walkie-talkie, radio was CB, etc.... You get the idea.) There was also a video being circulated of a Connie Chung news broadcast relating similar horror stories of the effects of EMC. We used to have a copy here, but I haven't seen it in years -- probably dumped when we moved.....My 2 cents worth......Mike HopkinsThermo KeyTek ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
