Even in a small plane I can reach altitudes where I can see 3 or 4 states with the bare eyeballs. We’re not talking about lighting up 8-10 towers, more like every tower from South Bend, Indiana to the Mississippi. The system may be designed to handle a few phones making multiple hits - what about a couple hundred phones each lighting up a hundred or more towers? Because that’s what you’re looking at if half the people on a 747 are yakking at 30,000 feet.
As for what they interfere with… my own cellphone has provided background noise on the communication radios when I’ve forgotten to turn it off - which is usually how I know I left it on by accident. That’s without transmitting or actually using it to talk on.
There is anecdoctal evidence that cellphones can also interfere with navigational radios.
There are reports of them interfereing with instrument landing systems … so if you’re in bad weather be sure your electronic gizmos are off.
And whatever applies to cellphones also applies to Blackberries and Palms that can transmit signals – which is why Blackberries even have a little airplane icon on the menu so you can turn off the transceiver while you’re airborne.
This month in AOPA magazine there’s a report of a PDA causing false hits on a stormscope - which is a device pilots use to avoid bad weather. Not a good thing.
I don’t recall hearing about GPS problems, but that wouldn’t surprise me, either.
The upshot to all this is… no, your electronic device will NOT cause the airplane to fall out of the sky, and most of the time will not cause interferance but it CAN do so depending on where you are situated in the airplane, what you’re doing with it, and whether or not it’s “leaking” electronic interference. Which is why, as mentioned in an earlier post, a captain might tell everyone to double-check they’ve shut their whatsits off - because something up front is experiencing “noise” or static or acting wonky and asking you to turn the stuff off is part of the process of finding the problem and fixing it.
It would be most critical in bad weather or clouds, when the pilots and plane are most dependent on electronic navigational aids.
On the flip side, I’ve flown with operating electronics, including CB’s and ham radios, on and operating in the back seat and NOT had any interference. Why some times and not others? I don’t know, I’m just reporting from my experience. The regs also recognize this quirkiness, and at least under Part 91 operations (private flights) it’s up to the pilot in command to determine the safety of using any sort of electronic device - including, yes, gameboys in the rear seats.
But it’s just not practical to test the electronic toys and tools of every person aboard every commercial flight - so the airlines opt for the easiest course - just turn all the damn stuff off, then you know there’s no interference. Yes, it can be a pain in the butt. So can a 747 getting lost or, worse yet, botching a landing in the middle of a foggy night because the cellphone in seat 25C confused the instrument landing systems. Really, they’re not doing it to be mean, or jerk you around, or even force you to buy time on their really really expensive airphones. They’re doing it to keep you as safe as possible.
All your points are sensible. But the weakness here is that no matter how many rules there are about turning off electronic devices and how many times you make an announcement to that effect, there are certainly going to be cases where people have left them on (often without being aware of it).
So the designers of aircraft radios, navigation equipment, instrument landing systems, etc. had best pay attention to making these devices reliable even in the presence of functioning (or malfunctioning) consumer electronic devices. I don’t think anyone’s safety should depend on Fred (who fell asleep even before the aircraft pushed back) hearing the announcement and remembering that the cellphone in his carry-on bag is still on.
Ah, here we’re getting into matters of the real world.
In an ideal world everything you say is so - the electronics themselves would be shielded and this wouldn’t be a problem. However, we don’t live in an ideal world.
Most airplanes flying today pre-date the PDA, Blackberry, and cellphone, as do their various electronic innards. When those aircraft were built they WERE shielded/protected from the electronics of their day. Are we supposed to retrofit the electronics of every airplane in the world every time someone invents a new handheld toy?
(The airplanes I fly typically have radios and other gear that pre-date the invention of the portable computer. That one I flew in Tennessee last year, built in the early 60’s, had had its radio upgraded to transitors, but no chips or circuit boards. Locally, we have 70 year old airplanes still flying - you can’t install a radio because there’s no battery or electrical system on board the aircraft to power the equipment. Airplanes can last a very long time if properly cared for, and the tendency is not to replace anything unless you really have to because all this stuff is so damned expensive - about 10 times the cost of installing a new radio or GPS in your car.)
In fact, it’s one of the aggravations of avionics shops trying to get the needed aircraft electronics installed without interferring with each other. Every airplane I’ve ever flown has a little card mounted next to the compass, because the electronics in the airplane throw off the needle and you need the card to tell you what the error is (it varies with direction). The little card needs to be updated every time you install a new radio or navigational gizmo or anything that generates an electrical field.
Certainly, the effort to properly shield an aircraft’s sensitive equipment is made - that’s why there is usually no problem - but no one can foresee all circumstances. Because the penalty for screwing up in aviation (or just overlooking a small detail) can be extremely high aviation people tend to be really anal about even small stuff. It shouldn’t be too outrageous to ask someone to turn their phone and other stuff off for 10-15 minutes during takeoff and landing, and refrain from using the phone during the flight. If it’s soooooo important you MUST call someone they do provide the means for you to do so safely. Yes, it costs money - a phone that is guaranteed to NEVER interfere with the airplane electronics currently is an expensive piece of equipment.
Meanwhile, you have an experienced group of pilots on a commercial flight who can use their senses and experience to detect anamalous events in the cockpit, and their brains to locate and eliminate the problem - including going back to the passenger cabin and saying “Hey, check and make sure your cellphones are turned off”. You do, however, want to minimize how frequently the pilot(s) have to do this - their main purpose, of course, being to fly the plane. It may lack gee-whiz technology, but the human element is much better at detecting that sort of unexpected event and dealing with it than any computer is. Which is one reason we still have human beings flying passenger jets instead of completely automated systems.
We at least need to be sure the avionics can deal with the electronic environment actually present. We should not be so naive as to believe that an announcement to turn off cellphones and games actually ensures that these are always off.
It isn’t outrageous at all - it’s entirely reasonable. My point is that it can’t be viewed as highly effective. And because the consequence of a problem is, as you note, potentially large, an effective way of preventing the problem is called for here.
If a pilot feels that it has any possibility of solving a problem, he/she should by all means cause such an announcement to be made. But this is a remarkably lame, last-ditch way of trying to cope with electronic interference issues. What’s the chance on a 400-passenger flight that a couple of active electronic devices will escape attention. What if they are in checked baggage?
I don’t understand the problem here. It’s all about minimizing the likely hood of interference. If you make planes or the electronics for them, make sure a cell phone left in a suitcase won’t bring the thing down. If you fly on a plane, do us all a favor and turn your phone off, so we don’t discover a scenario the designers missed.
Part of the problem is that there is no set standard for either cellphones or aircraft avionics.
See, if there was just one cellphone design, and just one design for what’s in the cockpit then doing this would be simple - just put the two systems in close proximity while operating to determine if there is a problem, and if there is, deal with it just once. But that’s not the real world - in addition to all the myriad cellphone designs there are all the pager designs, PDA designs, handheld whatever designs… THEN you have all the variations on cockpit avionics invented since WWII. (Probably some even before that, but something that primative probably wouldn’t be affected by modern electronics anyhow). And it’s not even a matter of setting a national standard. Remember, airplanes travel. All over the planet. It’s not enough to say every plane flown by Delta is compatible with Nokia, Celluar One, and Motorola cellphones because the guy in seat 49G might have some weird thing he picked in Hong Kong or Dubai or Manilla that will cause havoc. It really is a complex problem because of the number of variables involved.
OK - you’re on the hot seat now. What would YOU consider an effective solution? Remember - you have to take into account that the FAA can only set standards for the US.
There are some things pilots do that probably would seem both strange and “less than effective” to non-pilots, but it’s really all part of a belt-suspenders-and-stickytape approach. Little sayings like “Always fly at least three mistakes high” - meaning give yourself ample time and space to recover from errors. Of course it’s better to never err in the first place but because you are dealing with complex systems AND human beings errors will occur. The purpose is to minimize the number of errors and the seriousness of errors. Aviation has to recognize that systems don’t always function as intended no matter how many safeguards are in place - so you must always have a backup plan, a second look, and double-check.
I flew with a carerr airline pilot in his private airplane and it was quite instructive. This guy checked five times when approaching an airport that the landing gear was down and locked. Mind you - the airplane is also full of various warning devices that would also remind him. But he has a routine where he checks and re-checks something that obvious and straightforward on every flight regardless of what he is flying. Why? Because warning systems can fail. Even in airplanes with fixed gear tires can go flat or ice up and you need to know these little details BEFORE you land.
Thus - no matter WHAT system you have in place to protect, shield, and ensure the proper functioning of the avionics in the cockpit you can NEVER trust it completely - because shielding can be damaged, systems to filter out “noise” can fail, and you never know what oddball things chance will put in your path. Even if a “foolproof” shielding system could be developed I guarantee that every time there’s unexplained interference with the systems up front the pilot(s) will ask that passengers turn off all electronic devices. It’s no different than if I hear something unexpected while flying and ask my passengers to be quiet for a minute - I’m elminating possibilities in order to determine what, exactly, is happening.
I assure you that the airlines are NOT relying on JUST asking the passengers to turn things off - it’s just that you don’t see what else has been done to elminate the problem. After all, you’re not in the maintenance shop watching the techs and mechanics do their thing. You don’t see a pilot sitting in a cockpit with his cellphone turned on to see whether or not it causes a problem, and if it does, what that would look like. The only reason you’re focusing in so hard on the announcement is because that’s the only part of the system you personally encounter.
If it’s in baggage it’s probably safer for everyone than if it was in the passenger cabin. For one thing, baggage is packed pretty tight, and the solid objects around such a device will probably provide enough barrier to avoid problems. Even if it doesn’t - the avionics, among other things, are checked prior to take-off. If a device is on in baggage and causing a problem it will (most likely) be discovered prior to takeoff. If it’s on and not causing a problem most likely no one will ever know. Either way, it’s not likely to turn itself on and off spontanteously in a hazardous manner. Nor is it likely to receive an incoming call while buried among suitcases in the hold, for the same reason my cellphone never rings when I’m riding the elevator at work - too much physical stuff for the radio waves to penetrate.
The big problem with stuff in the passenger cabin is all the bald bipedal monkeys who have access to it - people can turn stuff on and off. And we know cellphones can transmit and receive from inside those passenger cabins, which adds another variable. Cargo is pretty tame stuff - you tie it down and it stays in one plane, it never needs to go to the toilet, and it doesn’t argue. Passengers, however, can be their own worst enemies when it comes to air travel.
I’m not sure that your statement about no set standards is correct. There are a relatively small number of schemes by which cellphones operate, the specs for which are well understood. The RTCA (Radiotechnical Commission for Aeronautics) is one example of an organization that deals with standards for avionics.
I think we can agree that instruments and electronics critical to flight safety should be built to a high standard. One of those standards should be resistance to electronic interference at a level at least as high as produced by nearby consumer electronic products.
An effective standard would be that critical aircraft systems work reliably in environments where the background noise is twice that produced by typical consumer electronic products at ranges of half a meter (to include common malfunctions of those products).
The FAA sets standards for the US, but cooperates with a great many countries. If they suggest sensible approaches to problems faced elsewhere, they will be heard.
Right. I have something over a thousand hours as PIC (small aircraft only) and know that you are correct in your characterization of the prudent pilot’s attitude. I think that having electronics that are tested and known to be reliable in the real-world environments they will encounter is part of that prudence. I think that asking passengers to please not opeate devices that could interfere is fine, but at best a tiny part of the solution (and not one to be relied on).
My reservations about the announcement are related to the implied assumption that if you ask people to turn off electronic devices, you can then assume they’re off. I say that you shouldn’t make such as assumption - you should be able to conduct the flight in such a way that it will be safe whether or not a couple of those devices are left on.
Honestly, I don’t see that much essential disagreement between us here. We obviously share a view of flight safety and pilot responsibility. I have no problem with turning my cellphone off - I do so every time. But I do wonder whether the flight crew believes that this makes the flight safe. I can’t convince myself that it does, and I hope they can’t, either.
You don’t think cell phones cause interference? Turn on ANY electrical device connected to a speaker, place a current-gen cell phone within a few feet of it, and observe. Even when you’re not making a call you can hear a constant clicking or buzzing as the cell phone communicates with the tower. It doesn’t even have to be a radio - the same phenomenon occurs in my car when listening only to the CD player.
Obviously then, cell phones do interfere with electrical equipment. Now imagine 50-100 of these interference patterns overlapping in your ear as you try to communicate with, say, ATC. Not good
What if it’s impossible to eliminate all interference? All these electronic things generate electric fields, after all - how much shielding do you need to elminate all intereference or possibility of interference. They can’t keep the avionics from interfering with the compass, for goodness sakes!
You’ve stated a goal, not a solution. HOW would you achieve this standard?
What’s a “typical consumer electroinc product”? How much interference does it generate? Is there a range of interference levels - do cell phones generate a lot more than PDA’s or vice-versa? Why a half meter? Why not six inches or one furlong? Define “common malfunction”. What about UNcommon malfunctions? What type of shielding would you use? Does placement of aircraft antenna in relation to passenger seating make a difference and could re-positioning such antenna elminate much of the problem?
You don’t deal much with politics or the government, do you?
No, I am not convinced that reason drives international aviation rule-making - there is a LOT of politics involved, national pride, and egos.
Having had the “passenger from hell” experience I’d have to agree on that one.
To my mind this is sort of like the “Please return seat trays to full upright position” command. 99% of people do so - but there’s always some joker who doesn’t (or someone asleep). So the flight attendants walk the aisles to make sure. Same for electronic devices - the last several times I flew commercial the cabin crew walked the aisles just before take off and landing to make sure these commands were complied with.
Which still does not elminate the possibility of a cellphone forgotten in a pocket and left on. But if, for instance, the stormscope is acting wonky and the pilot knows where the antenna for that is located (which he is supposed to) it at least narrows down where in the cabin you have to approach people and say “could you please double check?”.
Yes, we’re just having a discussion about the details.
I don’t know about you, but I have a certain level of distrust and paranoia on any flight. I try very hard not to assume all is right and will continue to be right, and if something isn’t exactly what I expect it to be I don’t brush it off, I look for what’s wrong. So far, that attitude has served me well.
It probably is impossible. What you do is test your critical systems under conditions at least as severe as they’ll face when in service, to ensure their performance is acceptable.
By testing, as above.
This barrage of questions could be taken to imply that you believe testing for interference is a new and novel idea, whereas I’m confident that you know it isn’t. These questions are all routinely addressed in the design and testing of electronic equipment, something with which avionics manufacturers are very familiar. (Among other things, they must ensure that one device does not prevent proper operation of another.)
To ensure that electronic activity in the passenger cabin is well below a problem threshold.
Indeed. There is also some notable cooperation (e.g. JAR 22) and standardization (e.g. English as the language of ATC).
What you are describing here is the underlying caution that any prudent pilot brings to the task of flying an aircraft. I concur, and feel the attitude should embrace the design and performance standards of the avionics (as I strongly suspect is already the case).
