As one who has actually installed cell phones aboard aircraft I'd like to
second Ted's comments. EMI is not a major concern. Neither the FAA or FCC
voiced any concern over installing 25 watt radios. Sure, we had to submit the
proper paper work showing proper compliance with testing
procedures, etc. but everything was routine.
As several other respondents have pointed out, it is impossible to completely
test for a berserk iPod audio device oscillating in the UHF. Therefore
aircraft testing concentrates on EMI susceptibility rather than EMI
generation. Fault tolerance and fail gracefully are key aircraft design
concerns.
Aircraft routinely fly through many RF fields for which they have absolutely
no control. How about that 50 KW AM station or the megawatt ERP FM or TV
station? What about the kilowatt radars?
The most likely source of interference to the aircraft's nav system is the
aircraft's comm radios. They are side by side and run in the range of 25
watts. The aircraft systems have to be able to tolerate interference.
Finally for those that are concerned by fly by wire airplanes, most of the
wires are plastic fibers.
Ted Eckert wrote:
Actually, it is the opposite problem. Cellular telephone companies
don’t
like calls from aircraft because the airborne cell phones can see too many
cell sites. On top of that, the airborne phone can pass quickly from one cell
to the next. Their software doesn’t do a great job at handling which cell
takes a call and when it gets handed off to another cell.
Ted Eckert
Compliance Engineer
Microsoft Corporation
[email protected]
The opinions expressed are my own and do not necessarily reflect those
of my
employer.
From: ibmken [mailto:[email protected]]
Sent: Thursday, September 24, 2009 9:10 AM
To: [email protected]
Subject: Re: Article on "portable electronics" aboard airplanes
I wonder if the local cellular site was prepared for that many
simultaneous
calls from a single location.
On Thu, Sep 24, 2009 at 10:32 AM, Gartman, Richard <[email protected]>
wrote:
The best reason I have heard from a flight attendant (this happened only
once) for putting the computer away was " do you want a 5 pound projectile
flying around the cabin if there is an incident". You cannot argue with that
logic.
Does any on have the report of the KLM/FCC cell phone test that was
done in
Phoenix several years back. As I hear the story, a KLM "Boeing" aircraft was
filled with cell phones (one in each seat) and they all went active at the
same time. The intent was to see if a plane loaded with cell phones could
cause interruption to the aircrafts electronics.
I am sure this group would enjoy that report.
Have a great day
W. Richard Gartman, MS, CSP
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Ken
Javor
Sent: Thursday, September 24, 2009 9:18 AM
To: [email protected]
Subject: Re: Article on "portable electronics" aboard airplanes
While having stuff put away during take-off and landing makes sense,
just as
you say, protection of aircraft radio and navigation receivers is the
primary driver. Paralleling control of rfi on the ground, the first
such
rfi control only applied to radios, because of local oscillators, and
then
later applied to digital electronics, because the clocks and their
harmonics
could radiate just like the radio's LO could.
Ken Javor
Phone: (256) 650-5261
> From: Nick Williams <[email protected]>
> Date: Thu, 24 Sep 2009 15:02:55 +0100
> To: Ken Wyatt <[email protected]>
> Cc: <[email protected]>
> Subject: Re: Article on "portable electronics" aboard airplanes
>
> I've always understood that, certainly so far as commercial airliners
> are concerned, EMC was never really the issue. Far more to the point
> is the fact that take off and landing are statistically the most
> likely time for there to be an emergency which requires the
> passengers to be paying attention to what the cabin attendants have
> to say rather than listening to or fiddling with their personal
> possessions.
>
> It also can't do any harm for the cabin not to be cluttered up with
> laptops and other junk for people to trip over if you need to get
> everyone off in a hurry.
>
> Nick.
>
>
>
> At 22:26 -0600 23/9/09, Ken Wyatt wrote:
>> I thought I'd post this link to a semi-rant by one of the Gizmodo
>> editors on the use of electronics aboard aircraft. He brings up some
>> good points regarding the EMI properties of various gadgets. It's
>> also interesting how he and other non-EMCers think on the whole
>> subject.
>>
>> Has anyone on this list studied the emissions characteristics ("on"
>> versus sleep mode) for various portable electronic products?
>>
>> I'd love to not be hassled when using my Bose headphones.
>>
>> http://gizmodo.com/5366128/giz-expl
ins-how-to-fix-the-airlines-stupid-portab
>> le-gadget-rules
>>
>> Regards, Ken
>> ----------------------------------------------
>> Wyatt Technical Services, LLC
>> 56 Aspen Dr.
>> Woodland Park, CO 80863
>>
>
> -
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