This the hypothetical question is the title of a commentary by means of Walter Shawlee in a late issue of sister publication Avionics magazine.

This the hypothetical question is the title of a commentary by means of Walter Shawlee in a late issue of sister publication Avionics magazine. He points gone out that the issue of interference in the cabin from portable electronic devices (PED's) not no other than comes from recent incidents, still may have been escalated somewhat "by a newly come decision in Canada to ban small cavity phone operation from the cross-question areas in gas stations, upon the suggestion that they portray by action some kind of combustion hazard while refueling."

While confined apartment phones are the only steady transmitters carried aboard by passengers, and their use is banned in flight, he has other relate tos Tests in his laboratory of various PED's yielded a unexpected results. A simple Sony CD Discman had a pronounced signature. Large liquid crystal displays in computer toys and laptop computer also are advantageous emitters that do not grant themselves to simple shielding.

Updating his June Avionics article, here's Shawlee's latest take: "I would have dismissed this as a credible question a month ago, but I am disquieted now that signatures on approved items are long bigger than anticipated, and devices that shouldn't unruffled be emitting are doing so"

"The combined emission of a whole aircraft sated of users is the real mystery, as this means a broad band noise source of excessively large physical size, and significant animal spirits something never contemplated or imagined through the authors of DO-160," he said. DO-160 is the master environmental specification for all avionics devices.

In the nearest few weeks, he plans to begin standards in a chamber designed to measure emission signatures "with a 3-axis antenna to give a consolidated XYZ signature in common pass." He also plans to deliberately about interference with low signal of the same height receivers like GPS. Shawlee's goal is to provide airlines and other organizations with a quick go/no-go standard for suspect PED's. >> Shawlee, e-mail walter2@sphere.bc.ca<<

Actual Measurements of Emissions from Portable Electronic Devices Yield Unexpect Results

"The largest surprise was a simple Sony CD Discman. It had a pronounced signature in the range of approximately 20 to 50 MHz a completely unexpect and frankly startling arise A new IBM laptop also had a broadband high strength signature of over 100 MHz wide, and near interesting spikes higher in oftenness Much more importantly, the signature was function pendent meaning that a static power-on ordeal was worthless in determining emissions, and that...software-based emissions will make good much harder to firmly proof and quantity."

Source: Avionics magazine, June 1999

...

Home