--------------E29C750EE3BDCEB4C0D5A9AB
Content-Type: text/plain; charset=us-ascii; x-mac-type="54455854"; x-mac-creator="4D4F5353"
Content-Transfer-Encoding: 7bit
Roughly along this thread...
Aircraft builders (think big ones) are concerned about any electronic device
operated during flight that might interfere with vital aircraft systems. 12 MHz to
1.4 GHz systems clocks will concern them. Here is one reason: Interference...
Example: You may be in seat xxD running a laptop (or a home brewed wearable with
plastic enclosures that do not keep electromagnetic energy inside the case). Above
you behind the (plastic) overhead bins or passenger service units (reading lights, air
vents, O2 masks, attendant call buttons) is the coax between airplane antenna and
communication or navigation radios. You operate your unit in flight and the flight
deck people can't hear tower or air route controllers and miss vital clearances. Or
the nav radio looses its signal from a ground station and your flight goes off
course. At some point there may be consequences, big ones or little ones.
Also, any time you operate a transmitter of any kind in an airplane, it emits EM
radiation that can interfere with aircraft systems. This includes cell phones,
wireless (RF) network devices, ham and CB type radios to name a few. Even receivers
use oscillators (to tune the unit to the station you want) and your radio receiver can
interfere with aircraft systems.
When Boeing and Airbus design and build airliners, they try to keep them light and
strong (to make room for fat paying passengers). Shielding on aircraft systems is at
a level (weight) that is suitable for the known onboard systems. It is tested and
certified safe that way. Just because there is a LCD display in the seat back does
not mean a carry-on electronic device will be safe to operate.
On a different tact... those same aircraft builders have to worry about high
energy cosmic particles (not blocked by layers of atmosphere) that can "ping"
semiconductor devices and change their state. Your stuff can take a hit and the plane
won't go the wrong way (or something). During certification of airliners, many
circuits and systems have to be analyzed to understand the likelihood and control the
risks to levels acceptable to regulatory agencies (protecting our collective interests
and hides).
My last comment is where I see the greatest threat. Terrorism...
Some of your real life examples and experiences show that stuff can be put on a
plane that could bring it to harm and it need not have explosives. In writing this, I
wonder if it has already been done.
In my view, we should always ask before we operate our stuff on a plane. Do it for
three reasons.
1. Help the flight crew keep us safe even if they have to deny us out of ignorance.
2. Make airlines (and plane makers) aware we want to be using this stuff so they can
allow it (eventually) by doing the right shielding or analysis (or whatever) they need
to.
3. When the guy at the gate or x-ray machine does see something suspicious, it gets
the level of attention it truly deserves.
Tim Miner
--------------E29C750EE3BDCEB4C0D5A9AB
Content-Type: text/html; charset=us-ascii
Content-Transfer-Encoding: 7bit
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
Roughly along this thread...
<br> Aircraft builders (think big ones) are concerned
about any electronic device operated during flight that might interfere
with vital aircraft systems. 12 MHz to 1.4 GHz systems clocks will
concern them. Here is one reason: <b>Interference</b>...
<br> Example: You may be in seat xxD running a
laptop (or a home brewed wearable with plastic enclosures that do not keep
electromagnetic energy inside the case). Above you behind the (plastic)
overhead bins or passenger service units (reading lights, air vents, O2
masks, attendant call buttons) is the coax between airplane antenna and
communication or navigation radios. You operate your unit in flight
and the flight deck people can't hear tower or air route controllers
and miss vital clearances. Or the nav radio looses its signal from
a ground station and your flight goes off course. At some point there
may be consequences, big ones or little ones.
<br> Also, any time you operate a transmitter of any
kind in an airplane, it emits EM radiation that can <b>interfere</b> with
aircraft systems. This includes cell phones, wireless (RF) network
devices, ham and CB type radios to name a few. Even receivers use
oscillators (to tune the unit to the station you want) and your radio receiver
can <b>interfere</b> with aircraft systems.
<br> When Boeing and Airbus design and build airliners,
they try to keep them light and strong (to make room for fat paying passengers).
Shielding on aircraft systems is at a level (weight) that is suitable for
the known onboard systems. It is tested and certified safe that way.
Just because there is a LCD display in the seat back does not mean a carry-on
electronic device will be safe to operate.
<p> On a different tact... those same aircraft builders
have to worry about high energy cosmic particles (not blocked by layers
of atmosphere) that can "ping" semiconductor devices and change their state.
Your stuff can take a hit and the plane won't go the wrong way (or something).
During certification of airliners, many circuits and systems have to be
analyzed to understand the likelihood and control the risks to levels acceptable
to regulatory agencies (protecting our collective interests and hides).
<p>My last comment is where I see the greatest threat. Terrorism...
<br> Some of your real life examples and experiences
show that stuff can be put on a plane that could bring it to harm and it
need not have explosives. In writing this, I wonder if it has already
been done.
<p>In my view, we should always ask before we operate our stuff on a plane.
Do it for three reasons.
<br>1. Help the flight crew keep us safe even if they have to deny us out
of ignorance.
<br>2. Make airlines (and plane makers) aware we want to be using
this stuff so they can allow it (eventually) by doing the right shielding
or analysis (or whatever) they need to.
<br>3. When the guy at the gate or x-ray machine does see something
suspicious, it gets the level of attention it truly deserves.
<p>Tim Miner</html>
--------------E29C750EE3BDCEB4C0D5A9AB--
--
Subscription/unsubscription/info requests: send e-mail with subject of
"subscribe", "unsubscribe", or "info" to 
Wear-Hard Mailing List Archive (searchable): http://wearables.blu.org
please, Please, *PLEASE* don't subscribe through a forward/false domain
From Wear-Hard Mailing list Archive (WH)
Maintained by R. Paul McCarty
Archive created with babymail