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rd2(at)evenlink.com
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PostPosted: Thu Mar 30, 2006 10:20 am    Post subject: Cell phone Reply with quote

Thanks for the clarification.
r
do nor archive

_____________________Original message __________________________
(received from Brian Lloyd; Date: 06:13 AM 3/30/2006
-0800)


rd2(at)evenlink.com wrote:
Quote:


You are not mistaken, it is against FCC regs.

As I said in earlier messages, the use of *AMPS* cellphones (the older
analog phones that transmit using narrow-band FM in the 800MHz band) in
an airplane in the air is prohibited by the FCC. It is *NOT* against FCC
regs to use PCS phones (digital phones such as CDMA, TDMA, and GSM)
while in flight. As far as the FCC is concerned AMPS and PCS are
completely different services and operate under completely different rules.
--
Brian Lloyd 361 Catterline Way
brian-yak at lloyd dot com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)

I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery



--


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gmcjetpilot(at)yahoo.com
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PostPosted: Fri Mar 31, 2006 3:47 am    Post subject: Cell phone Reply with quote

Actually air carrier, schedule passenger airline, have FAR restrictions.

If its company policy (in the operation certificate or airline flt manual it's law), it is
forbidden. The FAR's are less spacific and more general, giving the Captain
(PIC) authority to allow certain portable electronic devices. However if explicitly
stated in the Op Spec's his hands are tied. Flight attendants are doing their job.

Airlines have there own set of custom rules they must abide by.

Most airlines allow cell use on the ground, after landing during taxi.
In flight below 10,000 forget any device.


Any Fan's of the Discovery Channel show Myth Busters? One
of the most recent discussed this very thing. It was interesting. It was
Episode 49,"Cell Phones on a Plane", first aired on March 15, 2006.

http://en.wikipedia.org/wiki/MythBusters_episodes:_Season_3#Episode_49_.E2.80.94_.22Cell_Phones_on_a_Plane.22


They did a test with a high powered Cell test transmitter and got an old
Cessna ARC VOR to jump. They tried it in Hawker Business Jet with
EFIS flight deck. No effect. They wanted to fly but where not allowed by
the FAA? FCC? The bottom line was it was BUSTED! Older aircraft can
be affected, but modern shielded systems are virtually impervious.
The FAA's stand at least with commercial traffic is to err on the side of
conservatism. At some lower altitude they will not work anyway.

Check local basic cable listings, it is well worth a watch.

How the cell phone companies feel about it? I don't know. I always heard
it would "block" too many towers but read here this is untrue?

Any device can put out RF. I don't want an argument of shielded
electronics, we are talking conservatism. Frankly if I am IMC flying an
apprach to Mins, I don't want any electronic decives on.
What about GA aviation? Well it is one of those things, no harm not foul?


Cheers George




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khorton01(at)rogers.com
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PostPosted: Fri Mar 31, 2006 6:15 am    Post subject: Cell phone Reply with quote

On 31 Mar 2006, at 06:39, <gmcjetpilot(at)yahoo.com>
<gmcjetpilot(at)yahoo.com> wrote:

Quote:


http://en.wikipedia.org/wiki/
MythBusters_episodes:_Season_3#Episode_49_.E2.80.94_.
22Cell_Phones_on_a_Plane.22
They did a test with a high powered Cell test transmitter and got
an old
Cessna ARC VOR to jump. They tried it in Hawker Business Jet with
EFIS flight deck. No effect. They wanted to fly but where not
allowed by
the FAA? FCC? The bottom line was it was BUSTED! Older aircraft can
be affected, but modern shielded systems are virtually impervious.
The FAA's stand at least with commercial traffic is to err on the
side of
conservatism. At some lower altitude they will not work anyway.

There are so many variables that it is pretty much impossible to
define a guaranteed safe set of circumstances to use personal
electronic devices. One device might be OK, but the next one of the
same model was misassembled, or dropped, and that could affect the
shielding. Most seats in an aircraft might be OK, but a few seats
might be close to a coax connector that might allow some signal to
leak into the coax. Most aircraft might be OK, but one serial number
might have a bad piece of coax. One cell phone model might be OK,
until the manufacturer changes the production process.

A few tests showing no interference do not constitute proof that
there cannot be interference under any circumstances. There have
been enough reports of interference from various devices to know that
there can be problems in the right set of circumstances.

I talked to a Canadair Challenger pilot about 10 years ago who
related an incident. They were in cruise, when they noted strange
indications on the NAVs. He sent the copilot back to the cabin to
see if anything strange was going on. He found the CEO's son playing
with a GameBoy. He asked him to turn the GameBoy OFF - the NAVs
returned to normal. Turned the GameBoy back ON, the NAVs started
acting up again. GameBoy OFF for the rest of the flight.

Quote:
Any device can put out RF. I don't want an argument of shielded
electronics, we are talking conservatism. Frankly if I am IMC
flying an
apprach to Mins, I don't want any electronic decives on.

I agree 100% for commercial ops. For private ops, it is up to the
PIC to use his own best judgement.
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8


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rv8ch



Joined: 10 Jan 2006
Posts: 250
Location: Switzerland

PostPosted: Fri Mar 31, 2006 6:19 am    Post subject: Cell phone Reply with quote

Quote:
How the cell phone companies feel about it? I don't know. I always heard
it would "block" too many towers but read here this is untrue?

I'm happy we have federal laws to protect the telcos when
they don't properly engineer their products.

Any of you that live in the mountains know that you can
get a signal from dozens of cell towers at any instant
when you are high on a mountain. The tower my cell
phone (GSM) normally attaches to is about 12 miles
away, across the lake. Sometimes I get one about
the same distance, but about another 10 miles south.
My phone is seeing *lots* of towers, as are all of
the other thousands of people that live in these
hills.

Also, back in the early 90s when GSM first came out,
I never turned off my phone. There was no PA
announcement asking you to do it, since almost no
one had a cell phone. I flew a lot (commercial)
and enjoyed tracking my progress by watching the
towers that I attached to with the "debug" mode
active my phone. I tried to make a call, and
even though I had a nice signal, I could never
make a call. Not once. My bud who is a GSM guru
said that at the speed we were flying, I was not
staying on a tower long enough. I think until
there are "towers" installed in the aircraft, we won't
have to worry about sitting next to someone yaking
their heads off.
--
Mickey Coggins
http://www.rv8.ch/
#82007 finishing
do not archive


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Mickey Coggins
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nuckollsr(at)cox.net
Guest





PostPosted: Fri Mar 31, 2006 6:26 am    Post subject: Cell phone Reply with quote

At 03:39 AM 3/31/2006 -0800, you wrote:

Quote:


Actually air carrier, schedule passenger airline, have FAR restrictions.

If its company policy (in the operation certificate or airline flt
manual it's law), it is
forbidden. The FAR's are less spacific and more general, giving the Captain
(PIC) authority to allow certain portable electronic devices. However if
explicitly
stated in the Op Spec's his hands are tied. Flight attendants are doing
their job.

Airlines have there own set of custom rules they must abide by.

Most airlines allow cell use on the ground, after landing during taxi.
In flight below 10,000 forget any device.
Any Fan's of the Discovery Channel show Myth Busters? One
of the most recent discussed this very thing. It was interesting. It was
Episode 49,"Cell Phones on a Plane", first aired on March 15, 2006.

http://en.wikipedia.org/wiki/MythBusters_episodes:_Season_3#Episode_49_.E2.80.94_.22Cell_Phones_on_a_Plane.22
They did a test with a high powered Cell test transmitter and got an old
Cessna ARC VOR to jump. They tried it in Hawker Business Jet with
EFIS flight deck. No effect. They wanted to fly but where not allowed by
the FAA? FCC? The bottom line was it was BUSTED!


<snip>

I saw this episode. If it were not offered with such good
intentions, it would have been laughable. Their techniques
for deducing sensitivity of various systems to radiation from
cell phone emissions demonstrated a complete lack of understanding
of how both systems work and how one conducts repeatable experiments
to quantify and qualify results.

Take it from someone who has written dozens of test plans and
spent a goodly part of a career in a screen-room, the "results"
from their tests had no scientific validity. Now, that's not
to say that their conclusion was incorrect . . . I've done a LOT
of testing of equipment that was radiated strongly by sources
that cover the cell phone frequencies and found no effect on
the equipment under test. Indeed, that's a design goal of the
supplier and a requirement for certification. Suffice it to say
that squirting a bit of RF around the cockpit while watching to
see if anything twitches is not a noteworthy test . . . I WISH
it were so simple. Could have save my bosses $millions$.

Bob . . .


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nuckollsr(at)cox.net
Guest





PostPosted: Fri Mar 31, 2006 6:40 am    Post subject: Cell phone Reply with quote

At 09:10 AM 3/31/2006 -0500, you wrote:

Quote:



<snip>
Quote:
I talked to a Canadair Challenger pilot about 10 years ago who
related an incident. They were in cruise, when they noted strange
indications on the NAVs. He sent the copilot back to the cabin to
see if anything strange was going on. He found the CEO's son playing
with a GameBoy. He asked him to turn the GameBoy OFF - the NAVs
returned to normal. Turned the GameBoy back ON, the NAVs started
acting up again. GameBoy OFF for the rest of the flight.

> Any device can put out RF. I don't want an argument of shielded
> electronics, we are talking conservatism. Frankly if I am IMC
> flying an
> apprach to Mins, I don't want any electronic decives on.

I agree 100% for commercial ops. For private ops, it is up to the
PIC to use his own best judgement.
Kevin Horton RV-8 (finishing kit)

This was almost certainly an in-band interference event . . .
meaning that the interfering device had emissions on a specific
frequency of interest. What the Mythbusters did not understand
was that risks were probably NOT due to emissions on the cell-phone's
frequency of operation but for unexplored and uncontrolled emissions
on OTHER frequencies shared with the aircraft's systems.

The idea that emissions on cell phone frequencies would affect anything
in the cockpit is a very weak concern . . . those things are fully
explored during certification of that equipment. The concern is that
electronics in the foreign system has emissions in the vhf or uhf
frequencies where on-board equipment is trying to resolve signals
of interest in the microvolt levels while being bombarded with
much stronger, local interference.

Bob . . .


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N1DeltaWhiskey(at)comcast
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PostPosted: Fri Mar 31, 2006 7:37 am    Post subject: Cell phone Reply with quote

---

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BigD(at)DaveMorris.com
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PostPosted: Fri Mar 31, 2006 9:32 am    Post subject: Cell phone Reply with quote

After trying unsuccessfully to implement a Pentium II 120MHz computer
in the cockpit of my airplane (until I suddenly realized, duh, that
the clock speed was smack dab in the middle of the aircraft band and
would break the squelch full quieting on about 100 different commonly
used aircraft comm frequencies), and then switching to a 240MHz
version of the same computer and still wiping out the entire aircraft
band with RF interference, I honestly don't know how airliners stayed
in the air back in the days when laptops were running at such slow speeds.

But, as Bob said below, it's not just the "one" main frequency that's
producing interference. In a laptop computer there are several
different clocks (aka transmitters) all putting out junk. In a
cellphone, you might have oscillators for the receiving circuits,
oscillators for the transmitting circuits, oscillators for the LCD
display, oscillators for the dial pad, the PC sync cable, the
bluetooth, the WiFi, the 400MHz CPU, etc. etc. etc. Every oscillator
puts out a signal on its design frequency, and on harmonics (2x, 3x,
4x, etc.), so I imagine a spectrum analysis of a typical airliner
with everybody playing on laptops, gameboys, PDAs, DVD players, etc.
must be an incredibly awesome sight.

I agree that the mythbusters have strayed and nowadays most of their
shows are mostly entertainment, with little real scientific evidence
to back up their "busted / not busted" binary logic.

Dave Morris
At 08:24 AM 3/31/2006, you wrote:
Quote:

<nuckollsr(at)cox.net>

At 03:39 AM 3/31/2006 -0800, you wrote:

>
>
>Actually air carrier, schedule passenger airline, have FAR restrictions.
>
> If its company policy (in the operation certificate or airline flt
> manual it's law), it is
>forbidden. The FAR's are less spacific and more general, giving the Captain
>(PIC) authority to allow certain portable electronic devices. However if
>explicitly
> stated in the Op Spec's his hands are tied. Flight attendants are doing
> their job.
>
> Airlines have there own set of custom rules they must abide by.
>
>Most airlines allow cell use on the ground, after landing during taxi.
>In flight below 10,000 forget any device.
>
>
>Any Fan's of the Discovery Channel show Myth Busters? One
>of the most recent discussed this very thing. It was interesting. It was
>Episode 49,"Cell Phones on a Plane", first aired on March 15, 2006.
>
>http://en.wikipedia.org/wiki/MythBusters_episodes:_Season_3#Episode
_49_.E2.80.94_.22Cell_Phones_on_a_Plane.22
>
>
>They did a test with a high powered Cell test transmitter and got an old
>Cessna ARC VOR to jump. They tried it in Hawker Business Jet with
>EFIS flight deck. No effect. They wanted to fly but where not allowed by
>the FAA? FCC? The bottom line was it was BUSTED!
<snip>

I saw this episode. If it were not offered with such good
intentions, it would have been laughable. Their techniques
for deducing sensitivity of various systems to radiation from
cell phone emissions demonstrated a complete lack of understanding
of how both systems work and how one conducts repeatable experiments
to quantify and qualify results.

Take it from someone who has written dozens of test plans and
spent a goodly part of a career in a screen-room, the "results"
from their tests had no scientific validity. Now, that's not
to say that their conclusion was incorrect . . . I've done a LOT
of testing of equipment that was radiated strongly by sources
that cover the cell phone frequencies and found no effect on
the equipment under test. Indeed, that's a design goal of the
supplier and a requirement for certification. Suffice it to say
that squirting a bit of RF around the cockpit while watching to
see if anything twitches is not a noteworthy test . . . I WISH
it were so simple. Could have save my bosses $millions$.

Bob . . .




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deej(at)deej.net
Guest





PostPosted: Fri Mar 31, 2006 9:43 am    Post subject: Cell phone Reply with quote

Dave Morris "BigD" wrote:

Quote:

I agree that the mythbusters have strayed and nowadays most of their
shows are mostly entertainment, with little real scientific evidence
to back up their "busted / not busted" binary logic.




What, you mean proving you can't die from your own farts in a sealed
room wasn't scientific? *wink* Smile

-Dj

--
Dj Merrill
Glastar Sportsman 2+2 Builder #7118
http://econ.duke.edu/~deej/sportsman/

"Many things that are unexplainable happen during the construction of an
airplane." --Dave Prizio, 30 Aug 2005


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LloydDR(at)wernerco.com
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PostPosted: Fri Mar 31, 2006 10:50 am    Post subject: Cell phone Reply with quote

That one was flawed in the sense the did one element at a time, and not
all of them at once. But regardless, I know many people who have body
odors I would not want to be sealed in with!

The one I found cool, was when they replicated the Australian airplane
accident when the prop chewed up the tail and fuse of the plane. In the
beginning the did not believe you could prop start and airplane...it
went downhill from there!
Dan
Definitely Do not archive

--


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gmcjetpilot(at)yahoo.com
Guest





PostPosted: Sat Apr 01, 2006 4:09 am    Post subject: Cell phone Reply with quote

Subject: Re: Re: Cell phone

Dj: THANK YOU! WINK Wink

Dave and Bob:


Come-on guys Myth Busters is entertainment. Lighten
up. Sorry I mentioned it. However they did get a
result albeit contrived, it was interesting and I
would not blow it off as laughable.

The test they did was valid for the hypothesis they
postulated. I think they defined their test objective
and tested for that. It may not pass FAA/FCC mustard
but it was interesting.

I think its fair to evaluate the transmission freq of the
celphone as the potential main offender. Spurious RF
coming out the back cover in a different spectrum is
always possible and almost expected. However most of
the electronics are shielded in the phone (I have a
friend at Ericsson-Sony). Notice FCC stickers on
electronic devices. "Other" RF is at much lower power.


Dave wrote:
>"..... and would break the squelch full quieting on
Quote:
about 100 different commonly used aircraft comm
frequencies), and then switching to a 240MHz version
of the same computer and still wiping out the entire
aircraft band with RF interference, I honestly don't
know how airliners stayed in the air back in the
days"

Dave if your laptop is wiping out your Com, I would
look into your avionics installation or get a new
laptop or both. Back in the day was only 20 years
ago, airplanes had few computers and laptop an cel
phones rare.

All major consumer electronic devices has to meet
FCC specification for EMF & RFreq interference. Before
everyone panics when the iPod, PDA or laptop comes
out on a plane, the power of the RF is so nil its of
little concern. Again as Kevin and yes Myth Busters
have shown, commercial aircraft are very well shielded
from RF, by design. Lightning strikes is even more of a
worry than a passenger laptop. Notice that FM radios
and many devices are forbidden at all times on airliners.

To be honest if you wanted to be perfect no portable
device should be used, including computers, but the
fly consumer, business traveler would not stand for
that. We agree the risk is small. Yes?

The truth is if there is enough power on the right freq
you can hurt any avionics, at least certainly the NAV
signal and even COM. Typical portable devices don't
radiate enough energy.



Dave wrote:
>"I agree (Bob) mythbusters have strayed and
Quote:
nowadays most of their shows are mostly
entertainment, with little real scientific evidence
to back up their "busted / not busted" binary logic"


Back to myth busters. If you think these guys are
buffoons, they have lots of consultants who are way
smarter than all of us put together. In fact on the
cellphone subject matter, I am sure their researchers
and consultants (aerospace avionics experts) helped
them define and limited the scope of the test and was
indeed valid for what it was.


Bob wrote:
>"demonstrated a complete lack of understanding"

>"Take it from someone who has written dozens of test
Quote:
plans and spent a goodly part of a career in a
screen-room, the "results" from their tests had no
scientific validity"

>"squirting a bit of RF around the cockpit while watching
>to see if anything twitches is not a noteworthy test.
>I WISH it were so simple. Could have save my bosses
Quote:
$millions$."

Bob, you obviously know more and could do better,
write them with your test plan. They often revisit
myths and retest. How do you do it Bob? I agree
the purpose is entertainment, which most TV shows
are. Just remember Bob it needs to fit into 15-20
minutes of TV time and be interesting. How many
EMF and RFI test have you done on avionics? I
thought you guys just bought what Honeywell or
Collins sold and you all just bolted it in.


AS FAR AS MYTHBUSTERS!!!

Aviation Related Mythbuster Shows:

Pilot 1 - "Jet Assisted Chevy" (JATO car flys)
Pilot 2 - "Vacuum Toilet" (Fat woman stuck to toilet seat )
Episode 9 - "Chicken Gun (vs piper windscreen)"
Episode 10 - "Explosive Decompression"
Episode 13 - "Jet (blast vs.) Taxi"
Episode 14 - "Chicken Gun (vs piper windscreen)" (Revisited)
Episode 32 - "Jet Pack"
Episode 33 - "Killer Brace Position" (seat test)
Episode 37 - "Escape Slide Parachute"
Episode 37 - "Exploding Hair Cream" (F-104 pilot O2 mask fire)
Episode 38 - "Explosive Decompression" (Revisited)
Episode 45 - "Shredded Plane"

Cel Phone Shows:

Episode 2 -"Cell Phone Destruction" (gas station fill-up blow-up)
Episode 33 - "Cell Phones vs. Drunk Driving" (dive now talk later)
Episode 49 - "Cell Phones on a Plane"

(info above found at http://en.wikipedia.org/)

Myth Busters RULES!

As a current airline pilot and former aerospace engineer DER
I can say episodes 9,10, 33 are killer. Yes Boeing spends
millions doing these test, but mythbusters reproduces valid
test for peanuts. Any one can spend money, but thats not a
measure of the quality of a test.

"Don't try this at home, we are what you call professionals"

Smile hahaha


Cheers George


-----------------------------------------------------
>From: Dj Merrill <deej(at)deej.net>
Quote:

>Dave Morris "BigD" wrote:
>I agree that the myth busters have strayed and
>nowadays most of their shows are mostly
>entertainment, with little real >>scientific
>evidence to back up their "busted / not busted"
>binary logic.

What, you mean proving you can't die from your
own farts in a sealed room wasn't scientific?
*wink* Smile
-Dj

------------------------------------------------
>posted by: "Dave Morris \"BigD\""
Quote:
<BigD(at)DaveMorris.com>
After trying unsuccessfully to implement a Pentium
II 120MHz computer in the cockpit of my airplane
(until I suddenly realized, duh, that the clock
speed was smack dab in the middle of the aircraft
band and would break the squelch full quieting on
about 100 different commonly used aircraft comm
frequencies), and then switching to a 240MHz version
of the same computer and still wiping out the entire
aircraft band with RF interference, I honestly don't
know how airliners stayed in the air back in the
days when laptops were running at such slow speeds.
>But, as Bob said below, it's not just the "one" main

Quote:
frequency that's producing interference. In a
laptop computer there are several different clocks
(aka transmitters) all putting out junk. In a
cellphone, you might have oscillators for the
receiving circuits, oscillators for the transmitting
circuits, oscillators for the LCD display,
oscillators for the dial pad, the PC sync cable, the
bluetooth, the WiFi, the 400MHz CPU, etc. etc. etc.
Every oscillator puts out a signal on its design
frequency, and on harmonics (2x, 3x, 4x, etc.), so I
imagine a spectrum analysis of a typical airliner
with everybody playing on laptops, gameboys, PDAs,
DVD players, etc. must be an incredibly awesome
sight.
>I agree that the mythbusters have strayed and

Quote:
nowadays most of their shows are mostly
entertainment, with little real scientific evidence
to back up their "busted / not busted" binary logic.
Dave Morris

--------------------------------------------------
>posted by: "Robert L. Nuckolls, III"
Quote:
<nuckollsr(at)cox.net>
>I saw this episode. If it were not offered with

Quote:
such good intentions, it would have been laughable.
Their techniques for deducing sensitivity of various
systems to radiation from cell phone emissions
demonstrated a complete lack of understanding of how
both systems work and how one conducts repeatable
Experiments to quantify and qualify results.

Take it from someone who has written dozens of test
plans and spent a goodly part of a career in a
screen-room, the "results" from their tests had no
scientific validity. Now, that's not to say that
their conclusion was incorrect . . .
>I've done a LOT of testing of equipment that was

Quote:
radiated strongly by sources that cover the cell
phone frequencies and found no effect on the
equipment under test. Indeed, that's a design goal
of the supplier and a requirement for certification.
Suffice it to say that squirting a bit of RF around
the cockpit while watching to see if anything
twitches is not a noteworthy test . . . I WISH
it were so simple. Could have save my bosses
$millions$.

Bob . . .


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PostPosted: Sat Apr 01, 2006 9:19 am    Post subject: Cell phone Reply with quote

At 04:07 AM 4/1/2006 -0800, you wrote:

Quote:


Subject: Re: Re: Cell phone

Dj: THANK YOU! WINK Wink

Dave and Bob:
Come-on guys Myth Busters is entertainment. Lighten
up. Sorry I mentioned it. However they did get a
result albeit contrived, it was interesting and I
would not blow it off as laughable.

Humor is, of course, in the mind of the observer.
If I observed a "cabinet maker" measuring with a
yardstick and cutting with an ax, it would seem
humorous to me. But if the guy was offering his
skills and techniques as a do-it-yerself show . . .
it's another matter.

Quote:

The test they did was valid for the hypothesis they
postulated. I think they defined their test objective
and tested for that. It may not pass FAA/FCC mustard
but it was interesting.

It was not valid. If you screen your refrigerator
for e-coli and find it 'clean' it does not explain
nor offer remedy for illness promulgated by fungi.

While they were setting adjacent to an airport
and experimenting to see if the OBS/VOR/LOC needle
"twitched" the radio was not in it's intended mode
of operation. Sitting in a cockpit attempting to
visually OBSERVE effects of interference was
totally lame (believe it or not, there are SOME
FAA approved tests that do just that . . .
absolutely mindless).

Science is deeply rooted in the quantified, qualified
repeatable experiment. The Mythbusters episode
on cell phones didn't even emulate science. The
episode on Franklin's kite/lightning experiment
was so badly hosed as to bring tears to the eyes
of real scientists.

Entertainment? Yes. Interesting? Most of the time.
I enjoy watching it. Valid as a teaching or
demonstration tool? Very rarely due either to badly
crafted experiments, lack of quantification, or to
a mis-understanding of the science they're attempting
to illustrate.

Quote:

I think its fair to evaluate the transmission freq of the
celphone as the potential main offender.

Absolutely not. When we find an actionable interference
problem to be fixed, it's NEVER at operating frequency
of the antagonist. The potential antagonist does what
it's supposed to do to function. You have strong emissions
sources on all aircraft. Transponders, radar, comm
transmitters, radar altimeters, etc. One EXPECTS these
signals to be strong in the vicinity of all potential
victims. Therefore, victims are designed and tested
to operate reliably in a predictable environment that
includes those signal sources.

Quote:
Spurious RF
coming out the back cover in a different spectrum is
always possible and almost expected. However most of
the electronics are shielded in the phone (I have a
friend at Ericsson-Sony). Notice FCC stickers on
electronic devices. "Other" RF is at much lower power.

Define "lower". Here is a exemplar emissions limits
plot from DO-160. Note that for some device to be
qualified to live in the real world of airplanes, signals
that it spews into the environment must be at or below
values on the curve:

http://www.aeroelectric.com/Pictures/Curves/Emissions_Limits.gif

Note that levels are cite in MICROVOLTS per meter. Note
further that emissions in frequencies of interest to on board
systems are restricted still further by as much as 20db
(100x smaller) in some cases.

Now look at:

http://www.aeroelectric.com/Pictures/Curves/Susceptibility_Limits.gif

Here we see that depending on what class of equipment is
being tested, it's bombarded by potentially interfering
signals measure in tens to hundreds of VOLTS per meter.
These signals may be tens of millions of times stronger
than the emission limits cited above. The run-of-the
mill testing for most electrowhizzies is done at 50
VOLTS per meter.

The idea that a cell phone or even their non-quantified
super-cell-phone signal would irradiate the airplane's
equipment at anything close DO-160 test limits is suspect.
In any case, the cell phone equipment radiates a signal
that is many orders of magnitude stronger than any "allowable
limits" cited in the earlier chart . . . and if any given
cell phone were being qualified for aircraft use, this
fact would be ignored. This is because it has to run at
that power level to be functional just like your 10W
comm transmitter, 100W transponder and 10KW radar.

This is why the emissions limit testing speak only to
spurious signals that are much smaller than susceptibility
limits which the Mythbuster's episode DID NOT explore
or demonstrate. I could take my personal cell-phone to
the lab and probably show that it could be qualified for
use on airplanes. Okay, how about your cell phone?
Or anyone else's cell phone? Given the huge numbers of
such devices that roll over in style and features
every few months, it's a given that they will NEVER
be qualified for use on aircraft simply because the
folks who design and sell them would not stand up to
the costs of qualifying each new model (about $25K
worth of testing for each product).

The idea that most individuals got from watching
the Mythbusters is that government imposed limits
on use of their phones is without foundation because
some entertainers were unable to duplicate an urban
myth for which they had no scientific data and
attempted to demonstrate with a yardstick and and
axe.

Quote:

Back to myth busters. If you think these guys are
buffoons, they have lots of consultants who are way
smarter than all of us put together. In fact on the
cellphone subject matter, I am sure their researchers
and consultants (aerospace avionics experts) helped
them define and limited the scope of the test and was
indeed valid for what it was.

Where are the facts to back up this statement?
I've seen nothing in their presentations that suggest
anything of the kind. When virtually all of Hollywood's
productions are stroked for entertainment value
at the expense of all scientific objectiveness
how is it that this one television show becomes
so elevated?
Quote:


Bob wrote:
>"demonstrated a complete lack of understanding"

>"Take it from someone who has written dozens of test
>plans and spent a goodly part of a career in a
>screen-room, the "results" from their tests had no
>scientific validity"

>"squirting a bit of RF around the cockpit while watching
>to see if anything twitches is not a noteworthy test.
>I WISH it were so simple. Could have save my bosses
>$millions$."

Bob, you obviously know more and could do better,
write them with your test plan. They often revisit
myths and retest. How do you do it Bob? I agree
the purpose is entertainment, which most TV shows
are. Just remember Bob it needs to fit into 15-20
minutes of TV time and be interesting. How many
EMF and RFI test have you done on avionics? I
thought you guys just bought what Honeywell or
Collins sold and you all just bolted it in.
AS FAR AS MYTHBUSTERS!!!

Aviation Related Mythbuster Shows:

Pilot 1 - "Jet Assisted Chevy" (JATO car flys)
Pilot 2 - "Vacuum Toilet" (Fat woman stuck to toilet seat )
Episode 9 - "Chicken Gun (vs piper windscreen)"
Episode 10 - "Explosive Decompression"
Episode 13 - "Jet (blast vs.) Taxi"
Episode 14 - "Chicken Gun (vs piper windscreen)" (Revisited)
Episode 32 - "Jet Pack"
Episode 33 - "Killer Brace Position" (seat test)
Episode 37 - "Escape Slide Parachute"
Episode 37 - "Exploding Hair Cream" (F-104 pilot O2 mask fire)
Episode 38 - "Explosive Decompression" (Revisited)
Episode 45 - "Shredded Plane"

Cell Phone Shows:

Episode 2 -"Cell Phone Destruction" (gas station fill-up blow-up)
Episode 33 - "Cell Phones vs. Drunk Driving" (dive now talk later)
Episode 49 - "Cell Phones on a Plane"

(info above found at http://en.wikipedia.org/)

Myth Busters RULES!

As a current airline pilot and former aerospace engineer DER
I can say episodes 9,10, 33 are killer. Yes Boeing spends
millions doing these test, but mythbusters reproduces valid
test for peanuts. Any one can spend money, but thats not a
measure of the quality of a test.

"Don't try this at home, we are what you call professionals"

Yes, just enough credibility to lull the uneducated
into mindless acceptance. Engineers and scientists do not
get a pass on any given piece of work just because they've
been mostly right and/or un-controversial in the past. Every
piece of work is fair game for critical review and real scientists
welcome the opportunity to resist any wedges that learned
individuals might try to drive into their ideas . . . it's how
bad ideas get headed off at the pass. In the cases of Franklin
and cell phone interference aboard aircraft, they were way
out in left field.

Bob . . .


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