Subject: RE: presentation-prep as safety hazard

From: "Maddux, Michel" <[email-masked]>
Date: Wed, 21 Mar 2001 12:29:26 -0600

Let me guess, I have the time to do research for you, that you are unwilling
or unable to do.  You say
that something is entirely anecdotal, I say that it isn't.  Do the research.
/m.

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From: "Marshall T. Rose" <[email-masked]>
Date: Wed, 21 Mar 2001 10:34:20 -0800

> that something is entirely anecdotal, I say that it isn't.  Do the
research.

you say the studies exist. i say i've never seen them. i'm not asking you to
do any research. i'm asking you to prove what you say: that you've already
seen them. there's quite a difference there.

or perhaps when you say that the studies exist, you're saying you've heard
the studies exist. i'd call that anecdotal.

all i'm asking for is a url or a report number or something that can be
researched. if someone can provide one, i'm happy to admit that i'm
mistaken. in the interim, i think it reasonable for me to say that the
"evidence" is all anecdotal...

/mtr

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From: "Ole J. Jacobsen" <[email-masked]>
Date: Wed, 21 Mar 2001 11:43:28 -0800 (PST)

IEEE Spectrum from about 3-4 years ago had a lot of information on this. I
don't have the issue here, but it's a starting place.

Ole

Ole J. Jacobsen 
Editor and Publisher
The Internet Protocol Journal
Office of the CTO, Cisco Systems
Tel: +1 408-527-8972
GSM: +1 415-370-4628
E-mail: [email-masked]
URL: http://www.cisco.com/ipj

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From: Colin Perkins <[email-masked]>
Date: Wed, 21 Mar 2001 15:36:18 -0500

>"evidence" is all anecdotal...

Mobile phones rather than computers, but it's a starting point...
http://www.srg.caa.co.uk/news/Gsm_intf.PDF

Colin

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From: <[email-masked]>
Date: Wed, 21 Mar 2001 15:57:23 -0500 (EST)

> that something is entirely anecdotal, I say that it isn't.  Do the research.

Meaning no disrespect, I believe he said that he had never seen any claims
that were not anecdotal.  "Claims which are not anecdotal exist" does not
answer this; only presenting such a claim would.  Couched in friendlier
terms, the discussion might have been:

A: I have never seen actual evidence that a problem exists.
B: I have.
A: Oh, really?  Where?
B: I don't know.  But I've definitely seen it - perhaps if you looked, you
would too.

At any rate, http://www.srg.caa.co.uk/news/Gsm_intf.PDF seems to indicate
that there are no recorded incidents of people eating each other to stay
alive on the side of a snow covered mountain, and later discovering that
it was all on account of a cell-phone.  It does not reference anything but
cellphones, however, so I don't see it as asserting a lack of evidence.
But they do go out of their way to assert that the reason for the study
itself is the inability to prove that odd behaviour believed to be caused
by radio interference was indeed so caused.

However, as someone who every week endangers the lives of hundreds by
driving on public thoroughfares, it would be quite hypocritical of me to
claim that safety for myself and others should ever take precedence over
one person's personal convenience.

-= flail? http://flail.com/ =-
 -= the online comic strip =-

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From: "Marshall T. Rose" <[email-masked]>
Date: Wed, 21 Mar 2001 13:04:14 -0800

> don't have the issue here, but it's a starting place.

ole - thanks. my basic question remains the same, setting aside the
non-reproducible anecdotal reports, can anyone point to an actual scientific
study, i.e., a controlled experiment. i've yet to see one...

/mtr

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From: "Kastenholz, Frank" <[email-masked]>
Date: Thu, 22 Mar 2001 08:45:13 -0500

>study, i.e., a controlled experiment. i've yet to see one...

Nothing to do with scientific studies, but...

First, here is FAR (Federal Aviation Regulation) 91.21:

 (a) Except as provided in paragraph (b) of this section,
     no person may operate, nor may any operator or pilot
     in command of an aircraft allow the operation of, any
    portable electronic device on any of the following U.S.-
    registered civil aircraft: 
     (1) Aircraft operated by a holder of an air carrier 
         operating certificate or an operating certificate; or 
     (2) Any other aircraft while it is operated under IFR. 
 (b) Paragraph (a) of this section does not apply to-- 
    (1) Portable voice recorders; 
    (2) Hearing aids; 
    (3) Heart pacemakers; 
    (4) Electric shavers; or 
    (5) Any other portable electronic device that the operator
       of the aircraft has determined will not cause interference
       with the navigation or communication system of the aircraft
       on which it is to be used. 
 (c) In the case of an aircraft operated by a holder of an air carrier
    operating certificate or an operating certificate, the determination
    required by paragraph (b)(5) of this section shall be made by that
    operator of the aircraft on which the particular device is to be used.
    In the case of other aircraft, the determination may be made by the
    pilot in command or other operator of the aircraft. 

 Effective Date Note: At 54 FR 34291, August 18, 1989, Sec. 91.21 was
 revised effective August 18, 1990, as set out above. 

Which, to the uninitiated, says that except for Portable voice recorders,
Hearing aids, Heart pacemakers and Electric shavers, it is not allowed 
_unless_ the airline has determined that it can be done safely (i.e. 
not interfering with navcom systems). So, the lack of a scientific study 
(if any) is strong evidence that the airlines have not made such a 
determination :-) There is probably also a hidden liability issue;
if airline X allows, say, laptops during landing and one of their planes
goes down, some lawyer can claim that X did not do adequate enough studies
to determine that things are safe, blah blah blah. Also, note the date
that the regulation went into effect... I suppose one could try to get the
FAA to change its mind, but the FAA is not known for moving quickly...

Second, ILS landing aids are radio systems that operate in the 
frequency range 108.10MHz to 111.95 MHz (this is _not_ GPS -- it's highly
directional radio beacons set up at airports). This is fairly close to
some of the frequencies inside of laptop PCs, so it is not unreasonable
to believe that interference _could_ occur. Having watched pilots do
instrument approaches, you really don't want them worrying about the possibility
that the guy playing blackjack will put the red-9 on the black-10 and
cause his ILS receiver to hiccup while he's in the scuzz, 10kts above VS0 
at 100'...

As to cell phones, there is another issue, one that I would have thought that
the engineering talent of the IETF would have spotted immediately -- think of
the handoffs as a 747 full of cellphones is zipping along at 600+ MPH...

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From: John Stracke <[email-masked]>
Date: Thu, 22 Mar 2001 15:03:18 -0600

>     (1) Portable voice recorders;

I hope this gets updated to specify *analog* recorders.  An MP3 recorder could be
pretty noisy.

--
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