Puff piece on the DANGER of cellphones and aircraft

I have seen Blackberries interfere with COM radios when they get e-mails. I heard the buzz and shut it off. Dangerous? I don't know but it was annoying.

WiFi may be an issue in some cases:
http://www.flightglobal.com/article...ction-to-address-wi-fi-interference-with.html

The US FAA is waiting for Boeing to issue a service bulletin to address Wi-Fi interference with Honeywell Phase 3 display units (DUs) before deciding if regulatory action is required.
"We're aware of the impending service bulletin. Once we get it, we'll determine if we need to take some regulatory safety action," said an FAA spokesman.
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As a sr. research engineer in the cellular field, who has looked at EMC issues with cellphones, I say this was a pretty good and balanced piece. I am not alarmed and if I was to offer any criticism on the piece it is that the issue is a serious one that is being addressed, but they focused a little bit more on the alarmist issues instead of the work that is ongoing to minimize the impacts by both the airline and cellular industries.
 
Hmm.... Is it that hard to block electronic signals from interfering with those "sensitive electronic sensors hidden in the cabin" ?

I still don't know if I beleive it is as dangerous as they say. Wasn't the initial reason to turn off electronics like cell phones strictly due to an FCC requirement?
 
ajstoner21 said:
Wasn't the initial reason to turn off electronics like cell phones strictly due to an FCC requirement?
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The rule to turn off all electronic items preceded the invention of cellular by several decades.

But there is indeed a rule by the FCC. Part 22 to be exact that states that cellphone in the 800MHz band cannot be used in flight. There is no FCC rule for cellphones in any other band. For example those that operate in the 1900MHz are regulated under Part 24 and no mention is made of operations in flight. In fact little is mentioned in Part 24 that is applicable to the technology itself.
 
ScottM said:
The rule to turn off all electronic items preceded the invention of cellular by several decades.

But there is indeed a rule by the FCC. Part 22 to be exact that states that cellphone in the 800MHz band cannot be used in flight. There is no FCC rule for cellphones in any other band. For example those that operate in the 1900MHz are regulated under Part 24 and no mention is made of operations in flight. In fact little is mentioned in Part 24 that is applicable to the technology itself.
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Interesting. You mean, we had portable electronics before cell phones?? :lol:

What types of cell phones operate on the 800 MHz band versus the 1900 MHz? One 3G/4G while other isnt?
 
scottd said:
Agreed. I can almost always tell when my student has his cell phone still on in his/her flight bag or pocket. I get a "buzz" in my ANR headset that is very recognizable just before a call is received. I can also hear a similar kind of noise in my headset when the ASR-9 or 11 radar sweeps past me while taxiing. All of these signals are noticable, but do electronic devices interrupt communications or navigation? Evidently Boeing thinks that it does...and maybe there's some truth to that.
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I've never once heard my Verison (CDMA network) phone make noise in the comm's. However, when I fly with people who I know have GSM phones, I can hear them all the time.
 
ajstoner21 said:
What types of cell phones operate on the 800 MHz band versus the 1900 MHz? One 3G/4G while other isnt?
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AMPS type analog phones, the original 'cellular' phones.

I don't think there is much coverage left for those anyway.
 
ajstoner21 said:
What types of cell phones operate on the 800 MHz band versus the 1900 MHz? One 3G/4G while other isnt?
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Nope not so simple.

Everyone is running some form of 2G, 3G or 4G and combination thereoff.

When cellular in this country first started 800MHz was the 'useless' band that was assigned to it. I say useless because there was not a lot of cheap good radio equipment operating in such a high band. The band plan was established for two operators per major trading area. So there was a band A and a Band B In the late 80s when cellular was starting to take off someone realized that we needed more spectrum so 1.9GHz or 1900MHz was targeted. Those band were governed under the new Part 24 rule which has far more text in it about how an operator needs to bid money to get the licenses than anything else. These PCS bands went to several upstart companies looking to get into the wireless world. There is now even some 2.1GHz and 2.5GHz spectrum being used. Most phones today are multiband and multimode.

For example AT&T runs GSM, EDGE, UMTS and soon LTE in several bands including 800MHz and 1.9GHz depending on which city you are in. Sprint runs CDMA, iDen, WiMAX, 1xEV-DO and an LTE trial in 1.9GHz, 2.5GHz and some other bands. Verizon runs CDMA, 1xEV-DO and LTE in several bands as well. There is no real pattern to any of this at all. The original FCC rules are barely even important to anyone any longer. Most of Part 22 for example still deals with analog AMPS cellular and just makes a mention of the other technologies. The real details are in the standards. But Part 22 still contains that old prohibition on airborne use of 800MHz cellular. I looked at getting it pulled a bunch of years ago, but the push back was for the vendors to then guarantee that cellphones would not interfere with aircraft systems. No lawyer would let any vendor ever say such a thing. So the paragraph remains.
 
Airline flights last 30 minutes to nearly 20 hours. Do you really want the idiot sitting next to you and all the idiots in adjacent rows to be allowed to shout into their cell phones for the entire flight?

Think about that.

I'm happy with the "No cellphones in flight." restriction.
 
I can tell you that in the last year, I have had intermittent failure alerts on my G1000 Nav1. In the last several months, I decided to add turn off all cell phones to my checklist, and have not had an issue since.
 
Wow! I had no idea there was so much to cell phones! Thanks Scott for typing all that!
 
KSCessnaDriver said:
I've never once heard my Verison (CDMA network) phone make noise in the comm's. However, when I fly with people who I know have GSM phones, I can hear them all the time.
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I can hear the buzz from my GSM phone if I forget to turn it off. I can also hear it in my computer if I lay the phone down next to it.
 
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99% of passengers can do without their cell phone for 4 hours or so. I'm willing to bet that 90% of people in general don't need a cell phone at all, it's simply a toy. I'm fine with the 'no electronics/no cell phones' rules especially on airplanes.
 
ScottM said:
Ghery will be along soon to clue us all into the real nitty gritty world of EMC.
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I've only been doing EMC for 35 years and I'm still learning more about it all the time. :D And just when people think they've got a handle on it, we (and I'm on the committees) change the standards. Not much, but just enough. :D :D I think we've got people on the committees who enjoy each other's company and having meetings around the world too much, so the circus continues. There's a reason I'm Premier Executive on United every year. :mad2:

Anyway, the limits on emissions that apply to computing devices date back many decades. We instituted them in the US in the late 1970s as personal computers were becoming popular and were causing widespread interference to radio and television. That problem has generally been fixed, both due to widespread compliance with the limits and the fact that the vast majority of TVs are now on cable, which makes them inherently more immune to interference. The big headache for the manufacturers now is regulators creating new regulatory schemes, or changing the ones they have without considering what they're doing. At least they use the same technical standards.

The limits are designed to provide a reasonable level of protection to radio and TV services, assuming the receiver and the computing device are sufficiently far apart. That's one of the problems in our planes, they aren't far enough apart. Hence, 91.21.

If you really want to learn about EMC a good place to start will be the IEEE International Symposium on EMC in Long Beach, CA. The week of August 15. And, yes, we do have a club for EMC engineers who are pilots. We might even have a get together if we think about it. Come join us.

Ghery S. Pettit, NCE
President Elect, IEEE EMC Society
 
It's impossible to find the smoking gun in the smoking hole of a 747 or a Medflight Helicopter. These interferences tend to be transient events. I have worked with medical equipment and have found enough interference with life support equipment to justify , against great opposition , the signage to warn of the possibility. Some areas of intensive care have been at the front end of finding these cause and effect mechanisms. Once they have to tell a parent to get off the phone in their kids room so the ventilator works properly I get the call. I WANT the CELL PHONE (PED) banned sign on my unit entries.
 
Nothing to add to the topic but the title got my attention. One of the meanings for Puff in German is slang for bordello.
 
alaskaflyer said:
http://money.cnn.com/2012/12/09/technology/in-flight-cell-phones/index.html?iid=Lead
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Well, CNN doesn't know all the facts. No surprise there.

I had a conversation with the chief scientist on EMC matters at the FAA earlier this year at an IEEE EMC Society Chapter meetings in Seattle. Dave told me about a recent case where Garmin was testing a new piece of avionics that included GPS. They were using a mobile phone and it appeared to be interfering with the GPS receiver. This is not anecdotal, this is verified fact - they took the hardware involved (product and phone) to the lab and duplicated the problem. The phone had a spurious emission from its power amplifier right in the GPS band. Every example of that model phone that they got their hands on did exactly the same thing. This isn't an "I heard it from a friend who heard it from his barber" type story. This is verified by people working on the hardware.

Needless to say, I still have concerns about transmitting devices being used on board aircraft. WiFi seems to be OK in that we had the old Connextions (sp?) by Boeing product and now airlines are fielding their own WiFi products on aircraft. But, they still prohibit use during taxi, take-off and landing. Looked at the tablets lately? My Google Nexus 7 only has WiFi, but it also has a GPS receiver. Some would argue that that receiver could be a problem, but my comeback to that is that it works, so if it isn't interfering with itself there's a better than even chance that it won't interfere with another GPS receiver. Other tablets also have radios in the mobile phone bands. We've already seen one mobile phone that tanks a nearly GPS receiver, so there's a potential problem there.

The jury is still out on this. I just saw on-line where the head of the FCC is talking to the FAA saying that the ban doesn't make sense. I think he needs to cool his jets a bit and stick to what he knows about. He is a lawyer, so it isn't EMC.
 
Ghery said:
Well, CNN doesn't know all the facts. No surprise there.

I had a conversation with the chief scientist on EMC matters at the FAA earlier this year at an IEEE EMC Society Chapter meetings in Seattle. Dave told me about a recent case where Garmin was testing a new piece of avionics that included GPS. They were using a mobile phone and it appeared to be interfering with the GPS receiver. This is not anecdotal, this is verified fact - they took the hardware involved (product and phone) to the lab and duplicated the problem. The phone had a spurious emission from its power amplifier right in the GPS band. Every example of that model phone that they got their hands on did exactly the same thing. This isn't an "I heard it from a friend who heard it from his barber" type story. This is verified by people working on the hardware.

Needless to say, I still have concerns about transmitting devices being used on board aircraft. WiFi seems to be OK in that we had the old Connextions (sp?) by Boeing product and now airlines are fielding their own WiFi products on aircraft. But, they still prohibit use during taxi, take-off and landing. Looked at the tablets lately? My Google Nexus 7 only has WiFi, but it also has a GPS receiver. Some would argue that that receiver could be a problem, but my comeback to that is that it works, so if it isn't interfering with itself there's a better than even chance that it won't interfere with another GPS receiver. Other tablets also have radios in the mobile phone bands. We've already seen one mobile phone that tanks a nearly GPS receiver, so there's a potential problem there.

The jury is still out on this. I just saw on-line where the head of the FCC is talking to the FAA saying that the ban doesn't make sense. I think he needs to cool his jets a bit and stick to what he knows about. He is a lawyer, so it isn't EMC.
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This was probably a phone using LTE. Lots of wideband noise. Really bad stuff too. 10-20MHz away with a rejection limit of -40dBm/MHz interference victims can be 10-20m away from the agressor transmitters.
 
ScottM said:
This was probably a phone using LTE. Lots of wideband noise. Really bad stuff too. 10-20MHz away with a rejection limit of -40dBm/MHz interference victims can be 10-20m away from the agressor transmitters.
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Scott, I don't know for certain, but I wouldn't be surprised.
 
Ghery said:
I just saw on-line where the head of the FCC is talking to the FAA saying that the ban doesn't make sense. I think he needs to cool his jets a bit and stick to what he knows about. He is a lawyer, so it isn't EMC.
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I think that is the main gist of the article I posted. He may be a lawyer but he runs the FCC fer' cryin' out loud. Industry influence? Maybe, but it's time the FAA puts up or shuts up (speaking of industry influence :rolleyes:).
 
Be very careful of FCC as a technical resource these days. They haven't had engineers worth a damn in charge in quite a while. And the Commission and various high level folks are politically bought and paid for. Re: LightSquared.
 
If portable electronic devices were much of a problem we would have seen evidence by now. Do you seriously think everyone has them turned off?
 
Everskyward said:
If portable electronic devices were much of a problem we would have seen evidence by now. Do you seriously think everyone has them turned off?
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No, I don't. But, see post #22 for what actually concerns me. I don't worry about what the FCC calls an "unintentional radiator" such as laptop computers, tablets or mobile phones in "airplane mode". I'm not aware of any documented cases of them causing problems, but I also don't work on aircraft as a profession. The higher power levels of intentional radiators, especially mobile phones, can be a problem, especially when they do things they aren't intended to do. That can be a problem.

Now, in the same meeting where I heard about this documented case of a mobile phone (multiple samples) causing problems a Boeing rep gave a presentation on a new method of measuring signal levels in an airframe from transmitters in the passenger cabin that takes a 2 week test and condenses it into 1 day, with more complete results. We can expect to see future aircraft designed to be significantly more immune to interference from PEDs. Only future aircraft, not the ones we're riding today. But...

Stay tuned.
 
A couple of decades ago when I carried a pocket pager, that little devil radiated enough RF to break the squelch on the scanner and on the 2 meter radio I had in my ham radio shack. For months I kept thinking there was a phantom signal in my neighborhood. OF course it was on my belt and only bothered the radios when I sat down at the electronics bench.

In the early days of GPS my COM radio (King) would cause the GPS to lock up when the COM radio was set on certain frequencies. I don't remember which they were and a search should show it up (too lazy to do it myself)
What would happen is the IF oscillators in the receiver would mix together and heterodyne to a frequency that was close to the GPS frequency and that signal would radiate backwards through the amplifier stages and onto the COM antenna. Even though this signal leakage was low power it was of course vastly stronger than the weak satellite signal.
Same deal with any device that has internal RF oscillators - and this includes anything with a CPU in it, PC, tablet, pager, phone, digital camera, etc.
For those of you with no background in electronics do some reading on superheterodyne.
 
Dr. O said:
A couple of decades ago when I carried a pocket pager, that little devil radiated enough RF to break the squelch on the scanner and on the 2 meter radio I had in my ham radio shack. For months I kept thinking there was a phantom signal in my neighborhood. OF course it was on my belt and only bothered the radios when I sat down at the electronics bench.

In the early days of GPS my COM radio (King) would cause the GPS to lock up when the COM radio was set on certain frequencies. I don't remember which they were and a search should show it up (too lazy to do it myself)
What would happen is the IF oscillators in the receiver would mix together and heterodyne to a frequency that was close to the GPS frequency and that signal would radiate backwards through the amplifier stages and onto the COM antenna. Even though this signal leakage was low power it was of course vastly stronger than the weak satellite signal.
Same deal with any device that has internal RF oscillators - and this includes anything with a CPU in it, PC, tablet, pager, phone, digital camera, etc.
For those of you with no background in electronics do some reading on superheterodyne.
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I have a similar issue today with my Garmin 196 in my pickup (2006 Chevy Silverado) - anytime the factory radio is in the AM band the GPS loses all it's satellite locks. 100% correlated. Step out of the truck more than about 15 feet and I get sat signals back. Change the radio to FM or XM and I get sat signals back. The sat signals are still there of course - it's just that the signal to noise ratio completely washes them out.
 
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airguy said:
I have a similar issue today with my Garmin 196 in my pickup (2006 Chevy Silverado) - anytime the factory radio is in the AM band the GPS loses all it's satellite locks. 100% correlated. Step out of the truck more than about 15 feet and I get sat signals back. Change the radio to FM or XM and I get sat signals back. The sat signals are still there of course - it's just that the signal to noise ratio completely washes them out.
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What type of antenna does the radio use for the AM signal ?
 
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