Tomkow you hear of this????
Tomkow you hear of this????
Ping.
WA Ping
Was it a Boeing Aircraft or an AIRBUUST SPECIAL?
Ping
Speculation:
One or two more A$$ HAT cell phone users, and the flight controls went offset. The pilot is to be commended, landing the aircraft with fuzzy responsive controls, landing long and putting her down hard ( blown tire.)
Kudos to the pilot!
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Everybody knows how difficult listening to the radio or watching TV becomes when someone is using the vacuum cleaner in the next room. The vacuum cleaner causes significant interference with the radio signal. I used to live in a house in Kensington, CA, with an electric garage door opener, activated from the road by a small radio device carried in my car. The door would occasionally open by itself, early in the morning, on some rainy days when SFO was using RWY 19 for arrivals, and the flight path came more-or-less overhead. Now, there’s an anecdote. I don’t know it was aircraft transmissions; I don’t know it wasn’t a passing taxicab whose driver was talking to base; I don’t even know it wasn’t a fault in the door opening mechanism. We may presume that the system was not very well shielded from electromagnetic interference, and it is certainly not certified to the same rigorous standards as avionics (`aviation electronics’).
Nevertheless, there are similar worries in aviation at the moment. Passengers use electronic devices on board aircraft, including some such as cellular phones that they shouldn’t in any case be attempting to use, and pilots have reported anomalies with their navigation equipment that seem to correlate with use of personal electronics in the cabin. An overview of the technical issues may be found in (Hel96).
There have been to my knowledge no reports so far of interference with electronic flight control on the Airbus A320/330/340 series or the Boeing B777. These systems are shielded very well against electronic signals, because they have to fly through radar beams and other electromagnetic fields that may be occasionally very strong. There is nevertheless some experience with electromagnetic interference with electronic flight controls. Five crashes of Blackhawk helicopters shortly after their introduction into service in the late 1980’s were found to be due to electromagnetic interference from very strong radar and radio transmitters with the electronic flight control systems (1). So concern about this phenomenon is not purely the result of speculation. It has actually happened, and it is appropriate to be concerned about the possibility of similar phenomena in transport aircraft.
Bruce Nordwall (Nor96), writing in Aviation Week and Space Technology in September 1996, reported on the topic of an RTCA report to the FAA Administrator. At the request of the FAA, RTCA Special Committee 177 was formed in 1992 to look into the possibility of interference with aircraft systems from electronic devices operated by passengers during flight. Such devices include laptop computers, Gameboys and, more insidiously, portable personal telephones employing cellular technology.
Nordwall reported the RTCA advisory group to be worried that no group was testing or systematically tracking the potential effect of passenger electronics on avionics. The group was also concerned that the flying public is not being educated about the potential hazard, and that the airlines must largely figure out how to deal with the issue themselves. Most airlines in the US already prohibit use of passenger electronics of any sort below 10,000ft altitude. There is most concern for the future; that rapid increases in the technology of personal communications may allow passengers to bring aboard with them, and inadvertently or surreptitiously use, devices such as personal satellite phones that may be capable of significant levels of electromagnetic radiation. The RTCA report recommends developing and installing devices in aircraft cabins that could detect and locate potentially harmful radiation coming from within the aircraft. John Sheehan, the chairperson of RTCA SC-177, kindly provided the Executive Summary of SC-177’s report, RTCA DO-233 (RTCA96). The Summary is included here as Appendix A.
Navigation systems are particularly vulnerable for two reasons:
they have parts devised to detect and act on signals coming from `outside’;
radio-based systems are particularly susceptible to low levels of interference.
Aircraft control systems are located entirely within the aircraft and are shielded from absolutely any signals not coming from one of their own devices; they are also not radio-based, but are based entirely on electrical signals conducted through wires as are most computer networks (in the future, maybe also light signals conducted through glass-fibre cables). Navigation avionics, on the other hand, must have some designed sensitivity to environmental radio signals in order to perform their function. Nordwall says
THe antennas of radio-based avionics may be affected by [electromagnetic] field intensities of only microvolts per meter. But being outside the aircraft, the antennas get some protective attenuation from the fuselage of radiation originating inside the aircraft. Non-radio systems generally have higher signal levels, and so are less susceptible to low levels of interference.
The hull of a metal aircraft forms an effective electromagnetic boundary between the outside and the inside of an aircraft. Electromagnetic signals find it hard to get in, or to get out. That is why the navigation and radio antennae on an aircraft need to be placed outside the aircraft hull. But while outside they must be sensitive, the navigation electronics inside the hull can be in principle just as well and securely shielded as control avionics, because there is no reason at all for navigation systems to be sensitive to electromagnetic signals coming from inside the aircraft — indeed, very good reasons for these systems to be very insensitive, namely, that there is lots of other electronics working there as well.
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http://www.rvs.uni-bielefeld.de/publications/Incidents/DOCS/Research/Rvs/Article/EMI.html
I just have to relate my first ever flight experience. This past summer, I took my very first flight. We were to take off from Nashville to Milwaukee at 9:22 AM. Of course the plane was late. When we finally boarded about 10:15 AM, another delay. They said they were experiencing electrical problems. They said they could just disconnect the thing that was giving the problem but it was the law that they had to wait for a liscensed mechanic to do it. That made me a little nervous. But anyway they took us off the plane and about an hour later put us back on the same plane. They said the problem wasn’t fixed but it shouldn’t give us any problems. Anyway after we landed in Milwaukee, (by then we had already missed our flight to Minneapolis) several officials came out of the terminal immediately and tied red flags on the plane. Now this electrical problem in Chicago. Yikes!
I was working in Dispatch today when our ops guy called and told us about the runway 22R being shut down. It could have been a lot worse. ORD was groundstopped for ZAU internals only and 10 mins after the Ground stop cancelled, they cancelled the program as well..
Thanks for the heads up. I’ve posted it on site.