plattypus1
join:2005-04-08
Riverside, CA
 ·Charter Pipeline
| It seems to me...
...that avionics shouldn't be vulnerable to a few 3-watt transmitters that aren't even in their band. I can see satellite phones, but cellular phones just seems to be a ploy to get us to use those $2-a-minute airphone thingies.
If I remember correctly, aircraft radio and navigation equipment is just above the FM broadcast band, around 110 or so Mhz VHF. GPS is up in the Ghz range (the two main carriers at 1.2276 and 1.57542 Ghz) Cellphones operate at 800-900 Mhz analog and 900Mhz and 1.8-2Ghz digital. They have to be FCC type-approved, and that means they can't emit spurious emissions to a certain degree. There just shouldn't be a problem.
Of course, I usually trust the judgement of Carnegie Mellon and the IEEE... |
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Joe123456789
join:2003-11-24
Des Plaines, IL | I have read that the mythbusters are going to test this. |
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evergreek
Boeing Rocks
join:2003-05-25
Hialeah, FL
clubs: | Its an FAA rule and they WONT chg it simple. Go to your local FBO and complain if you want it so bad, watch them laugh their butts off at you  . |
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russotto
join:2000-10-05
Collegeville, PA | It's an _FCC_ rule, not an FAA rule. |
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SterlingJ85
Obama 2008
join:2000-11-19
Millville, NJ
 ·PHONE POWER
| reply to plattypus1
There is no difference with analog/digital signals being in certain bands. The FCC never specified the technology that had to be used with cellular operators. In North America, the 800 MHz (aka. Cellular band aka. 850 MHz) and the 1900 MHz (aka. PCS band) are used. 800 MHz is the oldest, as it was the first bands to be used for analog (AMPS) systems (A/B side carriers @ 25 MHz each). This no longer the case, CDMA, GSM, iDEN, and analog all are able to operate in the 800 MHz area. However, you will mostly find iDEN (Nextel) in the high 700 MHz band.
900 MHz (for the most part) is public use spectrum.
900/1800 MHz are used in other countries, and thats why GSM phones and some CDMA phone support them. International Roaming!
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-Sterling |
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tshirt
Premium,MVM
join:2004-07-11
Snohomish, WA
·Comcast
| reply to plattypus1
said by plattypus1  :...that avionics shouldn't be vulnerable to a few 3-watt transmitters ....to be FCC type-approved, and that means they can't emit spurious emissions to a certain degree. There just shouldn't be a problem. type cerified= only means a company has submit documentation from their RF engineers on the theorical and prototype testing of their design. production changes and parts variation always results in a range of of output from any given unit of any product.
There just shouldn't be a problem.
Only in a perfect world.
Maybe more than a few 3-watt transmitters , newer planes with 5-600 seats with maybe 50% of the passengers phoning right before touchdown on a dark and stormy night...
the plane in auto-land right down to 50 feet
it's not the gross errors, easily noticeable to the cockpit crew that are the problem, but instruments showing the runway centerline 100 feet left or right of it's actually location, leaving the flight crew to make a judgement call during the last few (busiest) seconds of a flight.
accidents (airline/auto/industrial/home) are rarely from a single cause, but a series of malfunctions and errors coming together and ending badly.
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