more on 2 comments on cell phones in the air

[David Farber <dave () farber net>]

Begin forwarded message:

From: "Andrew D. Swart" <andrew () swart com>
Date: March 6, 2006 3:39:25 AM EST
To: btm () templetons com, glenn () glennf com
Cc: dave () farber net, ip () v2 listbox com
Subject: RE: [IP] 2 comments on cell phones in the air
Reply-To: andrew () swart com

> ...Commercial jet GPSs use, I believe, and external antenna
> outside the metal body of the aircraft in any event.

For various reasons, including the growing popularity of using portable
GPS devices, GPS antennas in smaller general aviation (GA) aircraft are
often found inside the plane, but under the slanted front windshield.
Very different from an external antenna that is presumably well-shielded
from passengers and their toys.  The paper's reference to a single
instance of GPS interference in a GA aircraft doesn't seem all that
useful without additional information.  Not only am I curious about
antenna proximity to the cell phone, but it would be useful to know
whether the GPS unit was "fooled" into calculating a false location, or
reported the loss of signal integrity (GPS receivers certified for
instrument approaches have signal integrity monitoring).

As a pilot, I would find research more useful if it directly looked for
adverse effects on common aircraft navigation equipment from
non-aviation, onboard transmitters (whether in the cabin or in cargo
areas).  Perhaps it would lead to revised standards for navigation
equipment installations, and fewer concerns that an innocently
overlooked device could harm us.

Andrew Swart



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