Subject: Jumbo jet nosedive: Walkman to blame?
"It all started with a rumor that was soon widely reported as
fact: a DC-10, on final approach to New York's JFK airport,
suddenly pitched violently to the left and nearly crashed. As
the story goes, the loss of control was caused by a first-class
passenger who had turned on his portable CD player."
>From _Airlines and the Electronic Device Furor: Just Where's the
Interference?_ by investigative journalist Peter S. Greenberg in the
Sunday, April 4 edition of the San Jose (California) Mercury News,
page 1T. He continues:
"'That story is nothing but a rumor,' says Anthony Broderick,
associate administrator for regulation and certification at the
FAA [Federal Aviation Administration - C.H.]."
"'We've checked every available source, and that event never
happened,' he says. 'The picture painted in the mind's eye of the
public is inaccurate. We've looked at electronic emissions for
years, and the odds are so remote that something like this ever
happened that we don't consider Walkmen, CD players or laptop
computers a serious safety issue.'"
"Specifically, Broderick explains that electronic flight controls
are designed to be subjected to high levels of extraneous
electronic emissions. 'In a worst-case scenario,' he says, 'there
are failure modes built into these systems so that if there was a
problem, the system would either shut down or there would be an
alarm...in our tests we subject aircraft equipment to
substantially more severe electronic interference than could ever
be caused by passive individual devices.'"
Greenberg's article also mentions a 1988 study conducted by the Radio
Technical Commission for Aeronautics, which is described as a non-
profit group that acts a a federal advisory committee. Greenberg says
the group's study reported that there was was not sufficient evidence
to prove that any of the following devices generated enough
interference to disturb aircraft equipment: AM/FM/casette players,
Dictaphones, hand-held video games, heart monitor units, portable
computers, high-frequency marine band radios, and cellular phones.
As a former private pilot, I have dealt with the FAA. In my
experience, they have ALWAYS considered aircraft safety to be their
top priority. And after millions and millions of airline operations
upon which to base an opinion, and after specific testing for
interference by consumer electronics equipment, the FAA appears to
find no reason for concern.
In my opinion, it does seem logical to wonder if a radio might
interfere with navigation receivers. After all, radios contain local
oscillators that can emit RF. In reality, though, the already tiny
(and unmodulated) signal -- inside of a metal shield (the plane's
fuselage) -- drops off to a truly miniscule level inversely
proportional to the distance.
Personal computers are probably the devices most likely to cause
interference, as they can emit a relatively large amount of broadband
RF (radio frequency noise). However, laptop computers have been used
on airline flights for several years now, and, to my knowledge, there
has been no evidence to suggest a problem.
-Craig Haggart, KC6VHO
Stanford Synchrotron Radiation Lab at SLAC
Menlo Park, California
[Crossposting to alt.folklore.science and .urban,
and donning the asbestos suit.]
From unknown Fri May 28 01:30:14 1993
From: email@example.com (James J. Lippard)