Re: McDonnell Douglas warns against carry-on electronic devices

From:         driscoll@src.honeywell.com (Kevin Driscoll)
Organization: Honeywell Systems & Research Center
Date:         08 Jan 93 01:30:30 PST
References:   1
Followups:    1 2 3
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In article <airliners.1993.2@ohare.Chicago.COM> rdd@rascal.ics.utexas.edu (Robert Dorsett) writes:
>
>"The reason for the warning, said McDonnell Douglas Aircraft Company,
> ...
>"These devices, says the company, 'include, but are not limited to,'
>citizen-band radios, cellular telephones, transmitters that remotely
>control devices such as toys, and portable compact disc players.
> ...
>"Examples of these nontransmitting devices are audio and video
>recorders and playback devices, electronic games, computers and
>peripheral devices, calculators, FM receivers, televisions, and
>electric shavers.

It is very strange that CD players are considered transmitters whereas 
devices with local IF stages are not.  Do you suppose in their hunt for
a scapegoat that all they could find was a CD player?  Also, I bet
there are some electric shavers that generate much more EMI than any of
the other above mention devices.

Current opinions vary about how much EMI an avionics system is protected
against, but 200 v/m is a typical number.  One would not expect the
above devices to produce such levels.  RF getting into the radio nav aids
is another matter, but that wouldn't cause a transient change in aircraft
attitude anyway.  Unless there is more to this story, this looks like a
case of the ignorant pulling a demon out of their hat.