As I said in earlier posting, ADF might be used to get a bearing to a known transmitter, and thus line up an approach, but it is not IFR and cannot be used as the sole source of information in order to make a safe landing. My experience is with transport, not general aviation class aircraft. On transports, the ADF loop is too far away from any passenger-carried equipment to cause a problem.
In principle, it would be easy to bank an aircraft via rfi. All that is needed is that the aircraft be on auto-pilot and the auto-pilot is responding to ground-based navigation transmissions for position information. That is what happened to that storied DC-10. ---------- >From: Cortland Richmond <[email protected]> >To: Ken Javor <[email protected]> >Cc: Mike Hopkins <[email protected]>, [email protected], [email protected] >Subject: Re: EMC-related safety issues >Date: Thu, Jan 3, 2002, 11:40 AM > > I'm old enough, Ken, to remember ADF approaches! But > laptop switchers often operate inband to frequencies > used by aviation non-directional beacons. This makes > them more of a threat than the harmonics from > lower-frequency ones. It is also, of course, > possible for the laptop's other emissions to > interfere with an ILS or VOR receiver. > > Some of the complaints I've seen have not been > rationally explicable, however. For example, at one > of my former employer's (no longer in existence) a > report was received that a laptop caused an aircraft > to bank two degrees. I've worked with aircraft > stabilization systems, and I've yet to figure out a > mechanism how that could happen. > > Cortland > (What I write here is mine alone. > My employer does not > Concur, agree or else endorse > These words, their tone, or thought.) > > Ken Javor wrote: > >> 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. >> >> > ------------------------------------------- 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] 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.
