Turn your electronic device off because of fog?
Discussion
Just did an EasyJet flight into Luton. landing was in fog, captain announced, then cabin crew where insistent, all electronic devices should be power off, not jut put into 'airplane' mode. This is all devices, laptops tablets etc. for low visibility landing.
Can anyone tell me why? I can sort of understand why transmitting devices may need to be in 'airplane' mode during a flight, but can see what affect a tablet or phone in airplane mode could have on an aircraft when it's landing in fog.
Can anyone tell me why? I can sort of understand why transmitting devices may need to be in 'airplane' mode during a flight, but can see what affect a tablet or phone in airplane mode could have on an aircraft when it's landing in fog.
Edited by megaphone on Thursday 2nd February 05:22
Probably just out of paranoia but as the pilot will essentially be landing the plane on instrumentation due to low visibility they'd want to be absolutely sure that nothing is going to interfere with those instruments at the last minute. Phones, tablets, laptops etc. can still be emitting radio frequency (RF) interference even if in airplane mode albeit at quite a low level.
I've had the same on a few BA short haul flights when the visibility has been so bad it's been an 'auto' landing. Couple of direct announcements and CC doing a few sweeps of the cabin. Obviously can't check every device has fully been switched off, but guessing it's just precautionary.
Have a listen to Episode 257 on here - http://airlinepilotguy.com/podcasts/ Four pilots discuss this at some point in depth.
They don't agree.
British guy feel's that in theory it could affect electronics and not worth the risk. American guys feel that a) it's b
ks and b) enough people won't turn everything off makes the efforts pointless.
They don't agree.
British guy feel's that in theory it could affect electronics and not worth the risk. American guys feel that a) it's b
ks and b) enough people won't turn everything off makes the efforts pointless.It's fast becoming industry standard. During Autoland there are a few seconds when 70'tons of metal at 160mph is about to hit the ground guided by some 1980's computers and miles of fine wiring.
Thus would be a bad time to discover that your faulty Chinese tablet with a 4G aerial was pumping out a load of RF transmissions.
So turn the bds things off for ten minutes.
You're in the sky in a small metal tube which is partly on fire and full of hydrocarbons and electricity.
Thus would be a bad time to discover that your faulty Chinese tablet with a 4G aerial was pumping out a load of RF transmissions.
So turn the b
ds things off for ten minutes. You're in the sky in a small metal tube which is partly on fire and full of hydrocarbons and electricity.
99.9 % of the time, an airliner you're flying on will be visually flown to a manual landing by your trusty pilots.
If the visibility is poor, as is fairly typical for this time of year, then the pilots are not legally allowed to fly an approach manually - instead the aircraft (if equipped) will be set up for a low-visibility approach to an autopilot-flown landing. Although the aircraft is closely monitored by the pilots, with strict roles and 'abort' criteria for equipment failures during the approach, you are essentially being flown to a landing by the aircraft's technology, rather than Joe Bloggs looking out of the window and landing the aircraft visually. From that you can probably glean which one could potentially be prone to, and/or affected by, RF interference!
You're asked to turn off electronic devices for no reason other than mitigating the risk - so, as mentioned previously, do everyone a favour and turn them off for the 15-20 mins or so that you're asked to.
If the visibility is poor, as is fairly typical for this time of year, then the pilots are not legally allowed to fly an approach manually - instead the aircraft (if equipped) will be set up for a low-visibility approach to an autopilot-flown landing. Although the aircraft is closely monitored by the pilots, with strict roles and 'abort' criteria for equipment failures during the approach, you are essentially being flown to a landing by the aircraft's technology, rather than Joe Bloggs looking out of the window and landing the aircraft visually. From that you can probably glean which one could potentially be prone to, and/or affected by, RF interference!
You're asked to turn off electronic devices for no reason other than mitigating the risk - so, as mentioned previously, do everyone a favour and turn them off for the 15-20 mins or so that you're asked to.
But some peoples lives are so much more important than the other 100+ people on the cabin! They must update their FB and instagram otherwise their 3 followers will be gutted they havemr learnt what colour their turd was that day!
As above turn the fking things off for 10 minutes, your not that important 
As above turn the f
king things off for 10 minutes, your not that important So the conclusion to my question. It's to mitigate the very slight risk that EMF from an electronic device 'might' affect the aircraft's systems?
And to those getting on their high horses. This was a thread about the reason why, no one is moaning about it. If I'm told to do something, I like to know the reason why.
And to those getting on their high horses. This was a thread about the reason why, no one is moaning about it. If I'm told to do something, I like to know the reason why.
r1flyguy1 said:
But some peoples lives are so much more important than the other 100+ people on the cabin! They must update their FB and instagram otherwise their 3 followers will be gutted they havemr learnt what colour their turd was that day!
As above turn the fking things off for 10 minutes, your not that important
I think you've not read the OP. As above turn the f
king things off for 10 minutes, your not that important megaphone said:
I think you've not read the OP.
Yep, i read it but after years of flying long haul, twice a month people still are obsessesd with using there phones during the last few minutes of a flight!All im saying is if they ask you to turn it off, then just turn it off for 10 minutes, who cares whether you 'really' need to, I do and your not that bloody important to not have to.
Ive left my phone on by accident whilst sat up front and gad had zero detrimental effects to avionics but i still turn mine off, if nothing else it saves the battery for when I actually need to use it
r1flyguy1 said:
megaphone said:
I think you've not read the OP.
Yep, i read it but after years of flying long haul, twice a month people still are obsessesd with using there phones during the last few minutes of a flight!All im saying is if they ask you to turn it off, then just turn it off for 10 minutes, who cares whether you 'really' need to, I do and your not that bloody important to not have to.
Ive left my phone on by accident whilst sat up front and gad had zero detrimental effects to avionics but i still turn mine off, if nothing else it saves the battery for when I actually need to use it
megaphone said:
I appreciate all the bluster. Still doesn't answer the question why ALL ELECTRONIC DEVICES they need to be POWERED OFF during a low visibility landing, which is what the thread is about.
It's not an exact science. Easier to have a blanket ban, rather than single-out particular devices.
Found this if it is any help
ILS is actually relatively simplistic as RF signals go. Both the localizer and the glideslope just consist of a pair of AM signals that are broadcast directionally. For both systems, the modulated frequencies are 90 Hz and 150 Hz. For the localizer, 90 Hz is broadcast to the left of the runway centerline and 150 Hz is broadcast to the right of the centerline. When the aircraft is aligned with the runway, it will receive equal strength signals of both frequencies. When it's to the right, it will receive more power from the 150 Hz signal and when it's to the left, it will receive more power from the 90 Hz signal. The glideslope works pretty much the same way, just with the 150 Hz signal transmitted below the glide path and the 90 Hz signal transmitted above it. [1] [2]
Now, suppose some passenger's electronic device is emitting a frequency that it shouldn't be. This is not exactly unheard of among consumer electronic devices. This is more common among devices manufactured in countries with less-strict emissions testing requirements/enforcement, but it's possible due to slight defects in almost any device. [Source: I design RF receivers for a living.] Now suppose that this noise happens to be on the localizer or glideslope frequency for the runway to which the aircraft is flying an approach. Hopefully you're starting to see a problem here... Whatever amplitude changes are happening on this unintended emission are now being received by the AM demodulator of the localizer or glideslope, potentially confusing it and, in low visibility conditions, causing the aircraft to be directed somewhere other than the runway threshold. Needless to say, that's bad.
Normal Cat 1 approaches do not have such stringent minima requirements and its safe to say should you need to make a go around your not that close to the ground.
However CAT3/3B approaches with invariably have 0 feet decision height, the margin for error is extremely minimal and with the higher sensitivity of the approach equipment its best to reduce any risk of interference. One of the reasons the hold point for aircraft awaiting departure is set further back in comparison to CAT1 hold points.
ILS is actually relatively simplistic as RF signals go. Both the localizer and the glideslope just consist of a pair of AM signals that are broadcast directionally. For both systems, the modulated frequencies are 90 Hz and 150 Hz. For the localizer, 90 Hz is broadcast to the left of the runway centerline and 150 Hz is broadcast to the right of the centerline. When the aircraft is aligned with the runway, it will receive equal strength signals of both frequencies. When it's to the right, it will receive more power from the 150 Hz signal and when it's to the left, it will receive more power from the 90 Hz signal. The glideslope works pretty much the same way, just with the 150 Hz signal transmitted below the glide path and the 90 Hz signal transmitted above it. [1] [2]
Now, suppose some passenger's electronic device is emitting a frequency that it shouldn't be. This is not exactly unheard of among consumer electronic devices. This is more common among devices manufactured in countries with less-strict emissions testing requirements/enforcement, but it's possible due to slight defects in almost any device. [Source: I design RF receivers for a living.] Now suppose that this noise happens to be on the localizer or glideslope frequency for the runway to which the aircraft is flying an approach. Hopefully you're starting to see a problem here... Whatever amplitude changes are happening on this unintended emission are now being received by the AM demodulator of the localizer or glideslope, potentially confusing it and, in low visibility conditions, causing the aircraft to be directed somewhere other than the runway threshold. Needless to say, that's bad.
Normal Cat 1 approaches do not have such stringent minima requirements and its safe to say should you need to make a go around your not that close to the ground.
However CAT3/3B approaches with invariably have 0 feet decision height, the margin for error is extremely minimal and with the higher sensitivity of the approach equipment its best to reduce any risk of interference. One of the reasons the hold point for aircraft awaiting departure is set further back in comparison to CAT1 hold points.
Edited by r1flyguy1 on Saturday 4th February 13:37
r1flyguy1 said:
Found this if it is any help
ILS is actually relatively simplistic as RF signals go. Both the localizer and the glideslope just consist of a pair of AM signals that are broadcast directionally. For both systems, the modulated frequencies are 90 Hz and 150 Hz. For the localizer, 90 Hz is broadcast to the left of the runway centerline and 150 Hz is broadcast to the right of the centerline. When the aircraft is aligned with the runway, it will receive equal strength signals of both frequencies. When it's to the right, it will receive more power from the 150 Hz signal and when it's to the left, it will receive more power from the 90 Hz signal. The glideslope works pretty much the same way, just with the 150 Hz signal transmitted below the glide path and the 90 Hz signal transmitted above it. [1] [2]
Now, suppose some passenger's electronic device is emitting a frequency that it shouldn't be. This is not exactly unheard of among consumer electronic devices. This is more common among devices manufactured in countries with less-strict emissions testing requirements/enforcement, but it's possible due to slight defects in almost any device. [Source: I design RF receivers for a living.] Now suppose that this noise happens to be on the localizer or glideslope frequency for the runway to which the aircraft is flying an approach. Hopefully you're starting to see a problem here... Whatever amplitude changes are happening on this unintended emission are now being received by the AM demodulator of the localizer or glideslope, potentially confusing it and, in low visibility conditions, causing the aircraft to be directed somewhere other than the runway threshold. Needless to say, that's bad.
Normal Cat 1 approaches do not have such stringent minima requirements and its safe to say should you need to make a go around your not that close to the ground.
However CAT3/3B approaches with invariably have 0 feet decision height, the margin for error is extremely minimal and with the higher sensitivity of the approach equipment its best to reduce any risk of interference. One of the reasons the hold point for aircraft awaiting departure is set further back in comparison to CAT1 hold points.
Thanks for that makes perfect sense. You get so used to inconsistent rules and implementation its easy to wind up thinking its all nonsense and over inflated sense of importance.ILS is actually relatively simplistic as RF signals go. Both the localizer and the glideslope just consist of a pair of AM signals that are broadcast directionally. For both systems, the modulated frequencies are 90 Hz and 150 Hz. For the localizer, 90 Hz is broadcast to the left of the runway centerline and 150 Hz is broadcast to the right of the centerline. When the aircraft is aligned with the runway, it will receive equal strength signals of both frequencies. When it's to the right, it will receive more power from the 150 Hz signal and when it's to the left, it will receive more power from the 90 Hz signal. The glideslope works pretty much the same way, just with the 150 Hz signal transmitted below the glide path and the 90 Hz signal transmitted above it. [1] [2]
Now, suppose some passenger's electronic device is emitting a frequency that it shouldn't be. This is not exactly unheard of among consumer electronic devices. This is more common among devices manufactured in countries with less-strict emissions testing requirements/enforcement, but it's possible due to slight defects in almost any device. [Source: I design RF receivers for a living.] Now suppose that this noise happens to be on the localizer or glideslope frequency for the runway to which the aircraft is flying an approach. Hopefully you're starting to see a problem here... Whatever amplitude changes are happening on this unintended emission are now being received by the AM demodulator of the localizer or glideslope, potentially confusing it and, in low visibility conditions, causing the aircraft to be directed somewhere other than the runway threshold. Needless to say, that's bad.
Normal Cat 1 approaches do not have such stringent minima requirements and its safe to say should you need to make a go around your not that close to the ground.
However CAT3/3B approaches with invariably have 0 feet decision height, the margin for error is extremely minimal and with the higher sensitivity of the approach equipment its best to reduce any risk of interference. One of the reasons the hold point for aircraft awaiting departure is set further back in comparison to CAT1 hold points.
Edited by r1flyguy1 on Saturday 4th February 13:37
System seems a little open to abuse though, especially in todays enviroment. Do they actively monitor for people "fooling around" with certain transmitters/frequencies in the area of runways?
hairyben said:
System seems a little open to abuse though, especially in todays enviroment. Do they actively monitor for people "fooling around" with certain transmitters/frequencies in the area of runways?
The pilot will know the correct height for the given distance from the runway threshold and they will more than likely be using GPS as well as the glideslope indication from the instrument landing system to tell them where they are. If stuff starts going nuts, they can go around too. This is an example of the sort of info pilots use for instrument approaches (there's a few more pages to it, but this is the more interesting stuff):
https://fly.rocketroute.com/plates/adminview/EGLL_...
surveyor said:
Have a listen to Episode 257 on here - http://airlinepilotguy.com/podcasts/ Four pilots discuss this at some point in depth.
They don't agree.
British guy feel's that in theory it could affect electronics and not worth the risk. American guys feel that a) it's bks and b) enough people won't turn everything off makes the efforts pointless.
I agree with the Yank - especially b)They don't agree.
British guy feel's that in theory it could affect electronics and not worth the risk. American guys feel that a) it's b
ks and b) enough people won't turn everything off makes the efforts pointless.Gassing Station | Boats, Planes & Trains | Top of Page | What's New | My Stuff