From: jeffg@loki.esd.sgi.com (Jeff C. Glover)
Newsgroups: alt.radio.scanner
Subject: Re: Scanners in Airports and on Planes
Keywords: scanner airport planes
Date: 27 Jan 93 03:51:09 GMT
Distribution: usa
Organization: Silicon Graphics, Inc., Mountain View, CA
NNTP-Posting-Host: loki.esd.sgi.com

rcooper@world.std.com (ron w cooper) writes:
>Does anyone have any experience using a scanner in a major airport?  Do
>the security guys give you any trouble ?  Are there any rules (FAA etc)
>that prohibit you from using a scanner on planes ?

Since I've seen so much speculation being posted on the regulation,
here's the actual text from the FAA regulations:

FAA Regulations [ emphasis mine ]:

    Part 91 (1-1-90 edition)

    91.21 Portable Electronic Devices

    (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;
	(5) Any other portable electronic device that the OPERATOR of the
	aircraft has DETERMINED WILL NOT CAUSE INTERFERENCE with the
	navigation or communications 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.

==================================================

What's all that legal gobbledegook mean?  Basically, you can't use a
radio on a commercial flight.

Yes, even if the pilot says it's OK, it's not OK.  Read that last
paragraph carefully -- "OPERATOR" != "PILOT" for most commercial
flights.  And it doesn't say diddly about the OPERATOR assigning that
responsibility to the PILOT.  That is, United Airlines can't allow it's
pilots to determine on the spot whether a device is legit or not; they
(United Airlines) have to determine FOR A PARTICULAR PIECE OF EQUIPMENT
and FOR A PARTICULAR AIRCRAFT ON WHICH IT WILL BE ALLOWED.

Realistically, if the pilot says it's OK, you're not likely to be
prosecuted.  However, if an FAA inspector were aboard, noticed and
decided to act, the PILOT and OPERATOR could be subject to fines and/or
prosecution.

Replace "Radio" in all the above with "Any Electronic Device", and you
also exclude computers, NES gameboy, CD Players, etc.  Most airlines
have issued "determination" results for laptops and cd players.

The radio navigation problems involved in the prohibition have to do
with the FM broadcast band and the signals used for radio navigation.

FM broadcast band is approximately 88MHz to 108MHz.  Radio navigation
signals used in aircraft are from 108MHz to 118MHz.  When mixed with
the IF (10.7MHZ) of common (scanning) receivers, the FM broadcast band
signals mix to produce signals in the radio navigation band.  The
signals are often stronger than the weak navigational signals used by
aircraft.

I've experimented in a private plane using my scanner while flying and
observed deviations in the VOR of 40 degrees.  Simply turning the
scanner off "resets" the deviation; turning it on brings it back.

Would you want to be on an airplane in the clouds, in severe turbulence
while some joker back in coach is trying to listen to his FM radio or
scanner?  The airplane drifts 40 degrees off course, and ends up in the
side of some cumulogranite.

Jeff
jeffg@sgi.com