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akaSylvia
20th Jan 2011, 15:31
The New York Times has an article about electronics on board this week.

On a Phone, Interfering With Flight Safety - NYTimes.com (http://www.nytimes.com/2011/01/18/business/18devices.html?_r=2)

The excerpts that caught my attention:

But some passengers invariably ignore the request, perhaps thinking that their iPods or e-books do not count. And really, does it matter if the devices are left on? The answer, it turns out, is that sometimes it may.That seemed a pretty soft statement for an article on a mission.


“Is it worrisome?” asked Bill Strauss, an engineer who studied passenger use of electronic devices several years ago. “It is.” Safety experts suspect that electronic interference has played a role in some accidents, though that is difficult to prove. One crash in which cellphone interference with airplane navigation was cited as a possible factor involved a charter in Christchurch, New Zealand, in 2003. Eight people died when the plane flew into the ground short of the runway.Well, I thought the phone interference there was because the pilot was using the phone rather than interference with the navigation.

Certainly Halting The Cowboys who Fly on a Wing and a Prayer (http://www.iasa.com.au/folders/Safety_Issues/FAA_Inaction/wing&aprayer.html) is focused on the issue of the pilot using the phone when he should have been paying attention to the landing, rather than the fact that the electronics were turned on:

* If the call was deliberately made (rather than accidentally speed dialled as had happened before), it was unsafe, irresponsible and would have posed a severe distraction if he tried to listen to it during the approach. He had a "perhaps cavalier" attitude to using his phone while flying.

This seems in direct contradiction to the NYTimes focus on confused passengers not understanding what their electronic devices are doing in the background:

Some passengers are like Nicole Rodrigues of Los Angeles, who acknowledges that she listens to music on her cellphone when she is not supposed to. “In my head, I imagine it not being a problem,” she said. “The whole airplane is filled with electronics that are constantly on. Is my little cellphone going to make that big of a difference?” I started to write a blog post about this but well, I'm not an IFR pilot and so I'm not really sure how much of an issue the ILS being pinged by the phone simply turned on (rather than making a call) might be. I didn't want to come across as "of course there's no issue" although I'm thinking is "NY Times are grasping at straws to try to make a point for which there is not very much evidence."
Or am I oversimplifying?

aviatorhi
20th Jan 2011, 20:34
From what I've seen some ADFs go screwy right when a signal is being established. And you can hear the signal itself if you have the speakers or a headset on (sounds like a static clicking sounds for about a second or two). Other than that nothing happens. And, no it wasn't me using the phone but the courier forgot to turn theirs off more than once.

akaSylvia
21st Jan 2011, 17:10
I've heard the pinging and although annoying, it's not really what I'd call interference. I've gone over the accident report and although the possibility of electromagnetic interference is mentioned, I think the analysis makes it very clear that it wasn't considered a contributing factor.

I went ahead and wrote my blog piece:
Fear of Landing Phones Interfering with Flight (http://www.fearoflanding.com/accidents/phones-interfering-with-flight/)

Feel free to point out any errors / embarrass me publicly / beat me with a wet noodle if I messed any of the details up but I think it all looked straight-forward despite my lack of IFR experience.

bookworm
22nd Jan 2011, 09:24
Christchurch Accident report (http://www.taic.org.nz/ReportsandSafetyRecs/AviationReports/tabid/78/ctl/Detail/mid/482/InvNumber/2003-004/Page/6/language/en-US/Default.aspx?) for those interested.

Well, I thought the phone interference there was because the pilot was using the phone rather than interference with the navigation.

Indeed. Based on the statistics of road accidents where mobile phone use is a factor, would one deduce that cellphones interfere with critical systems in motor vehicles?

mattpilot
22nd Jan 2011, 10:38
I once was told that it has to do with frequency modulation. While the cellphone & aircraft systems use different frequency ranges to communicate with distant stations (cell phone tower vs ILS antenna, for example), the aircraft electronics and the pax electronic devices could modulate the external used frequency into a smaller shared internal frequency on various electronic components. I'm not an electronic engineer so i don't know anything about this, but apparently it can come to interference with engines if, for example, you are in an aircraft with tail-mounted engines and a pax in the very rear seat uses his cellphone, which could interfere with the electronics that control the engine controls - since they are fully electronic these days.

Always wondered if there's much truth to that or if that is just hearsay.

GlueBall
23rd Jan 2011, 12:14
Some aircraft are now configured and approved for in-flight mobile/cell phone use. :ok: