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From: ge@wn3.sci.kun.nl (Ge' Weijers)
Newsgroups: comp.sys.laptops
Subject: Re: Using laptops on airplanes
Message-ID: <2559@wn1.sci.kun.nl>
Date: 17 Dec 90 15:50:40 GMT
References: <160670@kean.ucs.mun.ca> <2236@abcom.ATT.COM> <90334.083553PZ2@psuvm.psu.edu>
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PZ2@psuvm.psu.edu (David L. Phillips) writes:

>In article <1990Nov29.225555.18236@batcomputer.tn.cornell.edu>,
>pwong@batcomputer.tn.cornell.edu (Patrick Wong) says:
>>
>>Last time when I flew USAir, the taped announcement said that computers
>>cannot be used only during takeoff and landing.  There is no mention that
>>computers cannot be used during cruising.  The funny thing is that the
>>announcement said no other electronic devices are allowed at all time.
>>
>You can also use tape players but not radios.  The problem comes from the
>IF (intermediate frequency) radiation used in radios and TV sets to modulate
>the RF (radio frequencies) pulled in from the "ether."  Tape players and
>computers do NOT generate those frequencies, or any significant radiation, for
>that matter.

I've tried this with my shortwave receiver. Portables definitely emit
RFI in HF and VHF bands. This is not surprising with the 8-16 MHz square
waves used as clocks. The signals are not very strong though. If airplanes
can't handle those signal levels they are intrinsically unsafe.

You can't use computer on takeoff because they don't want them flying around
and hitting things in an emergency.

Ge'

--
Ge' Weijers                                    Internet/UUCP: ge@cs.kun.nl
Faculty of Mathematics and Computer Science,   (uunet.uu.net!cs.kun.nl!ge)
University of Nijmegen, Toernooiveld 1         
6525 ED Nijmegen, the Netherlands              tel. +3180652483 (UTC-2)