Question about the use of electronics devices on airplanes

[Puppycow]

I'm about to take a flight and I was looking through the rules for the airline I will be taking and I saw the following new rules, which went into effect on October 1, 2007.

The use of the following devices on the airplane is prohibited at all times, not just during takeoff and landing:

Restrictions on the Use of Electronic Devices On Board
Due to revisions of the notification of Japan’s Ministry of Land, Infrastructure, and Transport, “Restrictions on the use of electronic items” were partially revised on and after Oct.1, 2007.
Following are the items cited in the notification, as the electronic devices which may interfere with the safety of flight operation.
You are required to comply with the above by Japanese Law, and failure to do so will result in a fine up to ¥500,000.

Devices prohibited of use at all times
The following, which emit radio waves when turned on:
Cellular phones, PHS (Handy Phone System),Transceivers, Radio operated toys, Wireless headphones, Wireless earphones, Wireless microphones, Built-in battery type IC tags, Personal computers, PDA (Personal Digital Assistance),Wireless personal computer peripherals, Electronic games, Pedometer with wireless transmission function, Cardio tachometer with wireless transmission function, Wrist watches with wireless transmission function, Wireless keys

Devices prohibited of use during parking, taxiing, takeoff, and landing*
The following, set in a condition that will not emit radio waves when turned on*,
TVs, Radios, Beepers, GPS receivers, Video cameras, Video players, DVD players, Digital cameras, Digital audio players, Wired battery-operated headphones, Wired battery-operated earphones, Word processors, Electronic notepads, Electronic dictionaries, Printers, Battery chargers, Toys “electronic virtual pets” (limited to items in which the speaker or monitor is activated to sound or vibration)

* During Takeoff: Until the fasten seat belt sign is switched off after takeoff or the announcement allowing the use of electronic devices is made.
During Landing: After the announcement prohibiting the use of electronic devices is made, up until you leave the aircraft after landing.
ANA may restrict the use of a certain device regardless of the above.
All cellular phones emit radio waves automatically when they are turned on in order to send their position to the ground station. Please switch them off before boarding the aircraft and do not switch them on until after deplaning, as the waves may interfere with the systems of the aircraft. To prevent interference, restrictions also apply to electronic devices in the cabin even when the aircraft is on the ground.

My question is, is this based on valid science? Could the use of such devices actually cause a safety problem?

 

[Grimoire]

I'm about to take a flight and I was looking through the rules for the airline I will be taking and I saw the following new rules, which went into effect on October 1, 2007.

The use of the following devices on the airplane is prohibited at all times, not just during takeoff and landing:

<snip>

My question is, is this based on valid science? Could the use of such devices actually cause a safety problem?

The problem is that in order to ensure safety, ever device would need to be tested to make sure it will not interfere with the electronics on the plane. This would be an expensive and slow process. So to be safe, they simply ban all of the devices.

 

[lionking]

My understanding is that this restriction is more about passengers remaining attentive to any announcements or instructions from cabin crew than anything to do with interference with electronics. Did Mythbusters do something about this?

 

[RossFW]

In the early days of non-digital cell-phones there were documented cases of interference with Radio Navigation aids, specifically the Instrument landing system (ILS).

This is a pretty low tech system (Locus of two fields of radiated energy supplying an alignment with the runway and glide path for vertical guidence) and prone to interference, but is still the primary system for landing guidence.

There was anecdotal evidence of RF interference with Fly-By-Wire control systems, but nothing has ever been proven.

Interestingly (hypocritically?) the airlines have now worked out they can make money out of on board cell-phone use, systems are being rolled out.

 

[lionking]

Cant get the Mythbusters link to work, but in Europe it seems there is not evidence of problems with cell phones on planes.

http://www.aviation.com/travel/080312-cell-phones-on-planes.html

 

[Puppycow]

Here is the Skeptoid episode on cell phones in planes

I love Mythbusters and it's my whole family's favorite show, but with their episode on the cell phone ban aboard aircraft, they did a disservice to those of us who hope to get this groundless ban dropped. In case you missed it, they did a test and concluded that cell phones can potentially interfere with an aircraft's navigation system. The only instrument they tested was a radio direction finder called a VOR, which detects a radio beam coming from a ground station and points its direction. In practice, VOR is on its way out, in favor of GPS. VOR stations are each assigned a unique frequency in the VHF range between 108 MHz and 117.95 MHz, which is right above the FM radio frequency range. By contrast, the lowest frequency used by any US mobile telephones is 700 MHz; and in European mobile telephones, 450 MHz. Since the frequencies are so incredibly different, the whole debate is ended right there, for all practical purposes. Mythbusters used an older VOR receiver that could be tuned to receive a much broader range of frequencies, which is why they were able to detect the mobile phone signal. To be more responsible, they should have admitted that this frequency was wildly different than what any aircraft might possibly tune to. As it was, they left viewers with an inaccurate, and alarmist, impression. Mythbusters called the myth "plausible". No, it's really not plausible; a cell phone cannot affect an aircraft's navigation instruments in the real world, and we'll have more on that in a moment. Maybe if you threw a cell phone really hard at the GPS, you could break something.
. . .
Boeing and Airbus routinely bombard their aircraft to harden them against every conceivable type of attack, physical and electronic, certainly including cell phone signals. If cell phones had the potential to endanger an aircraft, you'd be allowed to bring them on board in the same way as you bring dynamite on board. Meaning, not at all.

Oh well. I guess instead of playing with my portable video games I might be forced to *gasp* read a book or something.

 

[RossFW]

VOR is on its way out, in favor of GPS.

True, but ILS, which is also a VHF radio system is still very much the standard Precision Approach aid, and will be for many years yet, and VHF Voice radio is still the primary means of ATC communication.

 

[Doubt]

Interestingly (hypocritically?) the airlines have now worked out they can make money out of on board cell-phone use, systems are being rolled out.

But they still plan to make you turn them off during take off and landing.

Also, IIRC, the US airlines are only going to allow data service with no voice during flights. That is to keep people from annoying the person next to them.

 

[wafonso]

Oh well. I guess instead of playing with my portable video games I might be forced to *gasp* read a book or something.

My reading of those rules is that video-games (and PDAs etc.) cannot be used if they "emit radio waves when turned on". Say, if your video-game has an wi-fi transceiver that can't be turned off, for example, then the whole device should be off, but a regular video-game would be ok.

 

[shadron]

My reading of those rules is that video-games (and PDAs etc.) cannot be used if they "emit radio waves when turned on". Say, if your video-game has an wi-fi transceiver that can't be turned off, for example, then the whole device should be off, but a regular video-game would be ok.

Uh-huh. Now you try to convince that bubblehead in uniform that your game is a "good" game that doesn't emit soundless, tasteless, invisible emissions. S/he'll pull out their CIA standard, handheld, multispectral field-strength meter and give it a quick once-over.

No disrespect of the stewarding profession meant, by the way. To an engineer, everyone else is a bubblehead.

 

[LarianLeQuella]

The problem is that in order to ensure safety, ever device would need to be tested to make sure it will not interfere with the electronics on the plane. This would be an expensive and slow process. So to be safe, they simply ban all of the devices.

This I would say is the PRIMARY reason for banning all those devices. Imagine if every electronic device ever had to be tested against every piece of aviation equipment! And you thought that an iPhone was expensive now? The standards and levels of testing regarding aviation equipment goes well beyond what UL and the regular consumer testing involves. To saddle that on every manufacturer is prohibitive to say the least.

And yes, SOME devices actually DO cause interference, despite most folks thinking they can't possibly do so. I suppose better safe than sorry.

 

[Kestrel]

I'm about to take a flight and I was looking through the rules for the airline I will be taking and I saw the following new rules, which went into effect on October 1, 2007.

The use of the following devices on the airplane is prohibited at all times, not just during takeoff and landing:

My question is, is this based on valid science? Could the use of such devices actually cause a safety problem?

Devices designed to emit radio waves could in theory interfere with the navigation systems on the aircraft. The prohibition against using them is based on science.

The further prohibition of all other electronic devices during takeoff and landing may not be justified for consumer devices that meet current FCC standards for emissions. The rules were imposed because pilots believed that the devices were causing problems. Experiments designed to find out if the reported problems were actually caused by consumer electronic devices in the cabin did not confirm the pilots claims.

 

[Cuddles]

My question is, is this based on valid science? Could the use of such devices actually cause a safety problem?

Yes. There have been many examples of interference with aircraft systems due to use of electronic devices, with mobile phones and laptops being the main culprits. Although no crashes have ever been proven to have been caused by this, there is strong evidence that they have been.

There are two things to bear in mind though. Firstly, the FCC ban on mobile phone use on aircraft in the US is nothing to do with safety, it is because airborne phones passing over many base stations in a short time will tend to clog up the network by registering with multiple stations at once because they are not designed to switch stations that quickly. I don't know if other countries' regulations exist for the same reasons, but if I remember correctly the FCC rules are often copied by other countries.

Secondly, and by far the most important point, is simply this - it's just not that important to have these things turned on. Seriously, look at the graphic on the linked article. The third biggest culprit for causing malfunctions is video games. No matter how small the risk is, can it really ever be so small that it is worth putting a whole plane full of people at risk just so you can have 5 or 10 minutes extra on some pointless game? Even if you're doing more important things like work, is it really the end of the world if you have to wait a few minutes longer before turning things on?

 

[Silly Green Monkey]

They made me turn off my handheld sudoku machine.

 

[Uncle Vanya]

True, but ILS, which is also a VHF radio system is still very much the standard Precision Approach aid, and will be for many years yet, and VHF Voice radio is still the primary means of ATC communication.

I was just taking a look at the US RF allocation chart (Source) and while there is a large chunk of RF for Aero Mobile Radio (AMR) and Radionavigation in the VHF band, theres also a large chunk allocated in 960-1215 MHz and another one in 1300-1350, as well as a few slivers here and there in the 800 band. Now I'm no expert in AMR (everything I do is limited to LMR) but I can imagine that there may be some sideband noise or higher level intermodulation products* from cell phones in the higher band that is allocated for AMR and Aero Radionavigation.

Note that the chart I'm using is from 10/03, which is old, considering the restructuring of the RF spectrum going on, that information may very well not be valid anymore.

*Not likely, but possible

 

[wafonso]

Uh-huh. Now you try to convince that bubblehead in uniform that your game is a "good" game that doesn't emit soundless, tasteless, invisible emissions. S/he'll pull out their CIA standard, handheld, multispectral field-strength meter and give it a quick once-over.

Well, yes. In the end, I'd say that what is ok to use is whatever the stewards say is ok to use. I would recommend extreme caution when arguing with the crew...

 

[Hamradioguy]

Years before cell phones, 9/11 and the TSA I had a handhed ham radio transceiver (commonly known as a Walkie-Talkie) in my carry-on. When the screener saw this on the X-ray machine there was a major incident. The airline people pointed out that I couldn't use a two way radio in flight. I explained that I knew that and was merely carrying it to my destination. Then they said I couldn't even POSSESS the radio on boad. I said, "Show me the rule that says this." Around and around we went as boarding time got closer.

Now, this was the budget airline People's Express, which even allowed gigantic boom boxes and uncased guitars as carry-on items, and they aimed to please. So they checked with the pilot (Who by law has the final say-so in such matters) and the decision was made that I would be escorted out ahead of even the disabled and families with babies, and that upon entering the plane I would hand the radio to the pilot on the flight deck who would retain it there until the plane landed...at which time I would be the first off the plane, retreiving my radio from the flight deck on the way out. Overkill for sure, but it was kinda neat to be treated like a rock star.

Thank the FSM for cell phones: Nowadays my little walkie talkie looks enough like a cell phone that no one even gives it a second glance. A good thing, as I'm sure the days of handing questionable carry-on items to the pilot are long gone. (BTW, I've used that and similar radios on private aircraft while sitting a foot or two from the instrument panel, and there was never an indication of interference to any instrument. But for the FAA to test every kind of RF emitting device for potential interference? Yeah, not practical.)