This discussion is touching on several aspects of Personal Electronic Devices (PED's) aboard aircraft. Bruce Donham, of Boeing, has a two-year-old paper with some hard data at:
http://www.boeing.com/commercial/aeromagazine/aero_10/interfere_story.html Also, here's a cross reference to PED Electronic regulations: http://aviation-safety.net/events/ped/ped-regl.htm And, 106 pages of Aviation Safety Reporting System PED related history, current to May 2002, at: http://asrs.arc.nasa.gov/report_sets/ped.pdf This whole subject is about as confusing as EMF's and cancer. Regards, Ed Ed Price [email protected] Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military & Avionics EMC Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis >-----Original Message----- >From: Ken Javor [mailto:[email protected]] >Sent: Monday, September 16, 2002 6:33 AM >To: [email protected]; [email protected] >Subject: Re: New EU regulations - civil aviation > > > >I do realize there is a big difference in the use of cable >shielding/screening between general and commercial aviation practices. >However the same general aviation aircraft that get by with >little or no >cable shielding/screening also have no electronic critical >flight controls, >so it is a wash. Any aircraft with flight controls qualified to >RTCA/DO-160A will also have its maximum degree of automation limited to >using the autopilot, possibly in conjunction with navigation >inputs from >aircraft NAV receivers. Both the rf (coax) and the base-band >signal inputs >into the autopilot would be shielded in my experience. I >would definitely >NOT expect personal electronics to interfere with such control systems >(except for that all-important radio link). > >I would also expect that as an older aircraft gets avionics >upgrades, with >avionics qualified to RTA/DO-160D, that the cables connecting >to the new >avionics must be upgraded if the certification is to maintain validity. >Specifically, if a new avionics upgrade were form, fit and function >compatible with the old part, but required a shielded harness to meet >RTCA/DO-160D, then that cable would have to be retrofitted >along with the >equipment. Am I being overly idealistic and out of touch here? > >In any case I reiterate: basic systems engineering practices >mandate that a >(non-rf) signal that carries flight critical information >should be piped >through the aircraft such that neither cross-talk nor stray >emissions from >other electronics cause interference. > >Along these lines, there are those who mourn the passing of >the old term, >rfi, because the term evoked the concept of RADIO >interference, rather than >the general term electromagnetic interference, which is global in its >meaning. We need to consciously retain the idea that stray >(unintentional) >rf emissions from non-antenna connected electronics have the >potential to >create only rfi. >---------- >>From: [email protected] >>To: [email protected] >>Subject: Re: New EU regulations - civil aviation >>Date: Mon, Sep 16, 2002, 1:57 AM >> > >> >> Firstly all avionic equipment is qualified to RTCA/DO-160 (European >> equivalent EUROCAE ED-14). >> All new equipment is test to DO-160D however there is still equipment >> installed on aircraft that was originally tested to DO-160A. >> Overtime the DO-160 has become more stringent with tighter >emission levels >> and high immunity test levels which includes HIRF testing. >> >> There is one problem that arises from this as most of the >cabling installed >> on the aircraft is unscreened. This is for weight saving reasons. >> >> Therefore with alot of older aircraft having a mixture of new and old >> equipments installed using cabling that is unscreened it is >reasonable to >> assume that some Passenger Portable devices such as Gameboys, Laptop >> Computors, Mobile Phones, etc. will if that passenger >happens to be sitting >> above a cable run cause interference with one or more >aircraft systems. The >> UKCAA keeps a log of all reported incidents. >> >> Regards >> Andy >> >> >> Andrew Price >> Principal Development Engineer (EMC Specialist) >> BAE SYSTEMS Avionics >> A125 >> Christopher Martin Road >> Basildon, Essex >> SS14 3EL >> >> tel: +44 (0) 1268 883308 >> email: [email protected] >> ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
