Well, the author is either ignorant, or he has glossed over the realities. In turn:
One cannot verify that a device won't cause interference by flying it on a single flight, or any reasonable number of flights. All of the possibly susceptible navigation and communication devices would need to be tuned to all the emitted signal frequencies to which these radios can be tuned. Further, the aircraft would need to be at the maximum required distance from the transmitting tower to ensure the SNR was worst case. The proper way to clear an aircraft for this sort of issue is a spectrum analyzer survey of the aircraft antennas. That way all the possible interfering signals can be collected at once, and the data can be analyzed as to whether there is a potential problem or not. BTW, this is WAAAY cheaper than a flight. And it's even cheaper than using a grounded airliner. An aircraft of the right type, but completely stripped and non-functional, is all that is necessary. The aircraft would need the appropriate antennas installed as in a flying aircraft, but that's it. But even given all that work, how do we know that all iPads (not picking on them, but just a name with which I'm familiar) are all the same? Do they all have exactly the same processors/RAM/what have you running at all the same frequencies? If a clock changes from one in which harmonics were out-of-band to a radio but now they are in-band, there could be a problem. Or if an IC has its internals modified, but is a form/fit /function drop-in equivalent, that can change the emission profile as well, and the device manufacturer wouldn't even know, because the IC manufacturer didn't change a part number. The fix here is EMI qualification testing of every variant that is sold, as longs as the manufacturer is aware of any and all changes to his internals. But even that isn't enough, because unlike regular aircraft avionics, these PEDs are not under the control of the airline. They have likely been dropped, immersed in or at least come in contact with liquids and the bottom line is that an initial qualification of one unit does not necessarily qualify all units sold over their usable lifetimes. One would have to look at the design to see what specific EMI reduction methods were used, and how they might be affected by ordinary misuse over a typical life. We have to remember here that while ordinary EN55022 type qualification protects the turf of licensed broadcasters, and thus their means of making a living, with the aircraft COMM and NAV systems, we are putting lives and property at risk. It would be one thing if the FAA wasn't allowing PEDs to be used at all. All they are doing is prohibiting their use during taxi, take-off and landing. Given the above issues, it makes much more sense for the flying public to remain unplugged for a few minutes at the beginning and end of every flight. This isn't asking a lot. Ken Javor Phone: (256) 650-5261 > From: Pat Lawler <[email protected]> > Date: Sun, 18 Mar 2012 16:54:01 -0700 > To: <[email protected]> > Subject: New immunity testing by the FAA in the future? > > Almost sounds like a whole new industry -- the business of testing > aircraft for immunity to personal electronic devices: > > http://bits.blogs.nytimes.com/2012/03/18/disruptions-time-to-review-f-a-a-poli > cy-on-gadgets/ > > Pat Lawler > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society emc-pstc > discussion list. To post a message to the list, send your e-mail to > <[email protected]> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > > Attachments are not permitted but the IEEE PSES Online Communities site at > http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used > formats), large files, etc. > > Website: http://www.ieee-pses.org/ > Instructions: http://listserv.ieee.org/request/user-guide.html > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher: <[email protected]> > David Heald: <[email protected]> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
