Are you saying that the problem, for this incident, is with the immunity part of the standard?
-----Original Message----- From: Bill Owsley [mailto:[email protected]] Sent: Monday, March 26, 2012 2:20 PM To: [email protected]; [email protected] Subject: Re: [PSES] New immunity testing by the FAA in the future? An interesting situation I ran into; a 10's of kilohertz system with lots of harmonics that faded fast, got into a 915 MHz radio which then amplified a wide range of the kHz harmonics to levels notably above the FCC limits. Broadcasting on all frequencies for your listening enjoyment! From: Brian Oconnell <[email protected]> To: [email protected] Sent: Monday, March 26, 2012 12:42 PM Subject: RE: [PSES] New immunity testing by the FAA in the future? There ARE problems with some devices, but the ipad may not be a problem. USMC aviators have been using ipads in helicopters for almost two years (that I know). In same squadrons' aircraft, there have been reports of interference from other "external-use cockpit devices". Marine combat aviation is a harsh environment, but the equipment has better support than commercial aviation (you can work the techs unlimited hours and not incur additional expense). Brian -----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of Cortland Richmond Sent: Sunday, March 25, 2012 4:51 AM To: [email protected] Subject: Re: [PSES] New immunity testing by the FAA in the future? Hi, Derek (and group). Many of us have over a long career had the chance to work on aircraft systems (or others) for which immunity standards are imposed. In most cases the signals emitted from properly functioning, non-intentional-emitter PED do not ever reach the levels the subject equipment is required to tolerate. IMO, it is in those cases still not proper to say PED operation should be permitted during flight regimes. There remain sensitive spectra be investigated; VHF communications, VHF and UHF navigation and landing systems, IFF, DME/TACAN and TCAS systems and the like. There have actually been ASRS reports of PED's affecting flight situation indicators and ILS flags, so for such victim devices, it seems we do need to test to levels of emissions and likely at levels lower than those permitted normally. Intentional emitters are quite another matter -- see ED-118 re threat levels -- and systems that react to them may never have been tested against the particular threat one may pose. While DO-160 threat levels are higher than most of the PED's a person might bring aboard, most of the tests use a nominal modulation only ASSUMED suitable for the purpose. I am now thinking about the famous case of a GSM telephone which, being under 30 cm from a victim (oven controller) device, turned on a gas broiler and almost caused a fire. It does not help that those who make and sell aircraft systems have a great deal of incentive to do only the minimum required testing, and a good deal of disincentive to spend time going beyond that. We simply have not tested against all threats a passenger might carry, and this is another thing missing from our analyses. Some years ago I had occasion to test an automatic external defibrillator for emissions in the aircraft VHF and UHF comm, navigation and landing frequencies, IFF, TACAN/DME and TCAS ranges. It appeared at the time that none of the personnel at the firm I was then on contract to (or at the test labs being used) had ever done such a test. But it is OUR business to know the test is needed -- and if possible, see it gets done. I was writing the verification plan and was able to do so. Cortland Richmond - ---------------------------------------------------------------- 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]>
