Electronics Interfere With A Plane Pseudoscience Edition  - Page 1
Forum section: electronics / general

author: Sionyn
author_rank: Frequent Contributor
timestamp: November 07, 2012, 06:45:41 pm
content: if there no scientfic basesis for these rules why are they enforced why are the individuals peddling this junk aren't held resposible for their junk sciencehttp://news.bbc.co.uk/1/hi/programmes/fast_track/9766517.stm

author: Psi
author_rank: Super Contributor
timestamp: November 07, 2012, 11:07:46 pm
content: From your post i'm not totally sure which side of the argument your for/against?The rules exist because devices "might" interfere given the right circumstances.Airline safety is about knowing all the parameters of a system and you cant do that with so many electronic devices out there.It's impossible to account for all the emission power/frequencies/harmonics/transmission-repeat-rate from every device.I believe the chances of any consumer device causing issues to plane electronics, even when the device is transmitting, are pretty close to nil. But i totally understand why they have the rules against using them.Dave's video showing the fluke meter being taken out by a nearby cellphone proved that these sort of issues can creep into electronics.Now granted, Boeing probably EMI test more rigorously than fluke but still there is a possibility of susceptible airplane equipment.The whole issue is more about random anomalies. Situations where you get devices interacting in a way that is totally unexpected.

author: SeanB
author_rank: Super Contributor
timestamp: November 08, 2012, 04:41:22 am
content: Given that the on board entertainment systems have been responsible for air crashes I would expect the airlines treat all as potentially a liability, thus the ban.

author: JuKu
author_rank: Frequent Contributor
timestamp: November 08, 2012, 06:46:59 am
content: Quote from: Psi on November 07, 2012, 11:07:46 pmI believe that, too. But having had some exposure on aviation safety culture, chances "pretty close to nil" are not even remotely good enough.

author: Psi
author_rank: Super Contributor
timestamp: November 08, 2012, 07:31:21 am
content: Quote from: SeanB on November 08, 2012, 04:41:22 amYeah, its pretty scarey.I was told a story about a friend of a friend who was playing around with the in flight entertainment system on a flight.The system was touch based and the software was a mess.He found a pretty huge bug in one of the GUI controls. (Those edit boxes for numbers only, where you have up and down increment button. Sometimes called spinedits).The system would stop you from clicking the up or down buttons to get outside the min/max value but you could copy/paste in a value outside the range and continue to click.After a bit more clicking the variable must have overflowed and crashed the system because the screen went black along with every other in flight entertainment screen on the plane.The pilot returned the flight to the airport.

author: EEVblog
author_rank: Unknown
timestamp: November 08, 2012, 07:51:06 am
content: Quote from: Psi on November 07, 2012, 11:07:46 pmYou don't have to believe that, it's a simple fact born out by countless practical tests on a daily basis.There are about 100,000 commercial flights per day, and every one of them has many people using (deliberately or unwittingly) all sorts of electronic devices, many of which transmit.How many flights have crashed or had a problem as a direct result of this?Dave.

author: Stephen Hill
author_rank: Regular Contributor
timestamp: November 08, 2012, 08:16:12 am
content: Althought not an authority in science, Mybusters covered this and their conclusion was that mobile phones do not interfere with airplane instruments:http://kwc.org/mythbusters/2006/04/episode_49_cellphones_on_plane.htmlHowever, it does state at the end:Quote

author: Sionyn
author_rank: Frequent Contributor
timestamp: November 08, 2012, 09:00:46 am
content: its is rather bland i guess, what it doing is challenging the illogical stance of people who probably have no clue about physics let alone electrical physics.much like how the urban myth about using mobile phones in survo stations was started by ill educated attendant.

author: Stephen Hill
author_rank: Regular Contributor
timestamp: November 08, 2012, 10:05:32 am
content: Quote from: Sionyn on November 08, 2012, 09:00:46 amHas grammar in the UK really become this poor?Quote from: Sionyn

author: Unknown
author_rank: Unknown
timestamp: November 08, 2012, 10:56:38 am
content: The NYT reporter sounds like he has a techno-addiction!

author: baljemmett
author_rank: Unknown
timestamp: November 08, 2012, 12:02:20 pm
content: Quote from: Psi on November 07, 2012, 11:07:46 pmThere may also be other reasons for some parts of the rules -- for instance, the 'not using laptops during takeoff or landing' one might be less about possible interference and more about the screen backlight, in much the same way as the cabin lights are dimmed at those times. As I understand it, that's done so that passengers and crew are already acclimatised to the low light levels that would be available in an emergency landing should something go wrong; a bright laptop screen might defeat that, at least for the user.Just a thought, and doesn't explain other devices, but it might be an alternative to the "might interfere, ban it!" explanation in some cases.

author: G7PSK
author_rank: Super Contributor
timestamp: November 08, 2012, 06:26:50 pm
content: I once spoke to the captain of the flight I was on about the use of electronics on board and interference with systems. He said there was no problem as far as he was concerned with their use in flight, what his worried about is the kerosene vapor outside the plane when passengers start to disembark, if someone dropped a phone from the plane it might ignite the fumes on hitting the concrete and creating a spark.I understood that the first ban on mobile phone use was at the behest of the network operators as an airborne phone could be seen by too many towers at once and crash the entire network.

author: SeanB
author_rank: Super Contributor
timestamp: November 08, 2012, 06:39:47 pm
content: If the fuel vapour is at a high enough level that a spark can ignite it i do not want to be there, as the plane will be already on fire. JetA is hard to start burning, really hard. You can put out fires with it. Turn up the flow rate too fast in a jet engine and it will stall and blow the combustion front out of the rear. That is why commercial jet engines take 30 seconds to go from flight idle to full power, any faster and it goes flop. Even military jet engines take around 5 seconds to go from flight idle to full power, and another 5 to go to full afterburner. Any faster and it may flame out. The Top Gun just putting it flat out and hitting his head on the cushion is just fake, you feed in power slowly, but react fast when it is at full power.

author: nitro2k01
author_rank: Frequent Contributor
timestamp: November 08, 2012, 06:40:35 pm
content: Quote from: Stephen Hill on November 08, 2012, 10:05:32 amActually, the use of 'how' was correct.Quote from: Sionyn

author: Neilm
author_rank: Super Contributor
timestamp: November 08, 2012, 07:37:40 pm
content: Quote from: Stephen Hill on November 08, 2012, 08:16:12 amThe trouble with this episode is that when they did the test, they used a modern Lear jet. It was on the ground so they could broadcast noise in the cabin without violating the law.The big problem is that there are many aircraft that are 20+ years old. If the avionics on these aircraft have not been updated (and completely rewired) there could be problems. I know that there have been reports of older aircraft having problems when laptops became popular. Mostly due to poorly designed equipment in the first class seats as this is usually near some of the more sensitive avionics.Neil