iPod at 30,000 feet

Well, at least they admit that their information might be a bit sketchy.

This is a direct quote from their page on reports of possible electronic interference
http://asrs.arc.nasa.gov/report_sets_nf.htm

“A sampling of reports referencing avionics problems that may result from the influence of passenger electronic devices.” (bolding mine)

Inside this link we find these gems.
“All ASRS reports are voluntarily submitted, and thus cannot be considered a measured random sample of the full population of like events”

“Moreover, not all pilots, controllers, air carriers, or other participants in the aviation system, are equally aware of the ASRS or equally willing to report to us. Thus, the data, reflect reporting biases. There biases, which are not fully known or measurable, may influence ASRS statistics.” (their bolding, not mine)

The first two events, as well as the 5th, 7th, 9th, 10th, and 11th have nothing to do with possible use of electronic devices causing issues. The third lists it as a suspicion, but gives no evidence at all. The fourth stats a passenger was using a palm, but even the pilot states he cannot prove the palm was the cause. The sixth lists a cell phone as a possible cause for concern, but offers no evidence. The eight stats a woman was using a cell phone when pulling up to the gate, but again offers no evidence it caused the in flight problems.

There are about 100 reports listed. I read the first 11 and did not see any compelling arguments for electronic devices being the direct cause of in flight issues. If you’re going to offer something as a cite, please save us the work of having to look it up for you. If it is going to be this much information, please at least tell us where to look inside these 100 page reports to find the information you believes supports your claim.

You can’t use GPS under 10,000 ft (whn you have to turn off eveything)
Northwest allows GPS (I actually asked the pilot and he looked in a big binder).
I recently traveled on Midwest, and one of the FAs asked the more senior FA if the GPS was OK and it was. I’ve also used a GPS on Delta withjout problem.

Brian

I’m not going to spend a week doing database queries and writing a report for you, summarizing the relevant incidents from the database. You read a small fraction of one report that was a selection of recent incident reports. In the past, I’ve read several incident reports that singled out CD players as the cause of instrument problems, for example. I didn’t note their report numbers at the time.

Yes, the information is anecdotal and often incomplete. The ASRS was setup to capture information that wasn’t being collected by the established and formal methods of incident reporting.

I’m more interested in flight safety than “scientific proof” that X caused Y. This isn’t a new problem. Decades ago, it was discovered that ordinary FM broadcast receivers could cause interference with aircraft navigation receivers. Most people are unaware that almost any electronics device may be an unintentional radio transmitter. The real world is much more complex than most people think.

United forbids the use of GPS devices at all times, to the best of my recollection. Southwest may do so as well. (Sidenote: RC devices are a no-no at all times, and laptops/PDAs/other electronics with wireless networking capabilities are supposed to have that function turned off while in flight.)

Going back to the OP, it’s been my experience in the several flights I’ve been on in the last couple years that all electronic devices must be off during takeoff and landing, and while the seatbelt sign is on before landing/after takeoff.

I’m sorry, I got confused because the post that the post you’re referring to, refers to, was talking about mobile phones (Johnny L.A.'s post a couple above.) Jesus, that’s a tortured sentence, I’m tired, OK :).

You don’t need a cite to say that mobile phones cause static on a radio, it is a known fact. Try putting your mobile phone beside a transistor radio and you’ll hear the dit dit dit dit interference when someone rings it. This may seem innocuous at home, but it can be very distracting when that radio has an important clearance coming through at the time and you are in shitty weather and trying to concentrate.

It should be enough to know that your mobile phone, by being on, could distract your pilots right when they don’t need to be distracted, therefore, turn it off.

If you have a CDMA phone, it doesn’t do the interference thing BTW.

Now, I don’t know that any conclusive evidence has ever been found that mobile phones cause navigation errors on aircraft, there is anecdotal evidence, but it is sketchy and there is really no way of knowing the cause of a single isolated incident.

However, we know that mobiles definitely interfere with comms radios. Navigation aids all rely on radio transmissions, so it is possible that mobiles may cause abnormalities in navigation equipment. To me, that is enough to warrant turning the things off. They don’t need to be on, they are an annoyance to other passengers, they are an annoyance to the pilots, and there is a possibility that they could have a detrimental effect on the nav instruments, therefore, turn them off.

As far as laptops and other non-transmitting devices are concerned, there is not much reason to believe, IMO, that they can cause problems, hence they can be used in the cruise phase of the flight. I think Chronos hit the nail on the head with the reasons for disallowing them to be used during approach and departure, it’s a lot easier to have a blanket ban on electronics rather than trying to figure out which ones are transmitting, and which ones aren’t.

And yet it’s standard procedure to announce that mobile phones can be used when a aircraft has landed and is taxiing toward the gate. On the last flight I was on, at least 25 mobile phones were instantly put to use. If they “definitely” interfere, how could the pilots be confident of reliable communications as they are taxiing?

FWIW, a flight attendant once told me that the reason mobile phones (and other electronic distractions) are prohibited once the doors close is in the (perhaps vain) hope that it will increase the liklihood that passengers pay some attention to the pre-takeoff safety briefing.

Indeed, most do - and often on frequencies very close to those used for communication. So it’s an obvious design requirement that aircraft navigation equipment not be highly vulnerable to interference.

There’s also the point (it has been mentioned in previous threads on this subject) that telling people to turn off their mobile phones does not result in 100% compliance: some may ignore the request; others may simply forget that their phone is on. If there were any real evidence that mobile phone represent any real potential danger, it would be necessary to search for and confiscate these devices. Indeed, it would be seriously irresponsible not to.

I forgot once that my phone was on (it doesn’t ring, just vibrates and I rarely get calls on the phone). However, I do get text message updates of sporting events. So at 30,000 feet I was getting updates on a baseball game that I read as surreptitiously as possible.

That’s placing your cell phone right next to a transistor radio. I would hope that commercial electronics that are depended on for communication are built a little more stoutly to resist interference. I’m also not familiar with where the radios are located in an aircraft, or where the antennas are, but I am sure they are more than six inches away from where I sit.

Ya know, I’d have figured that by 1000 posts you would know better. When making claims of evidence to support your posts, it is incumbent upon you to provide the proof. Just saying “it’s in there somewhere” does not cut it. If you don’t want to take the time to show us where the evidence is, so it can be reviewed and scrutinized by fellow posters, it is as worthless as no evidence at all.

And since this message board is dedicated to the eradication of ignorance, I’d sure love some scientific proof. Sitting back and accept that CD players are bad “because they say so” may fly for you, but anyone truly searching for the truth will turn their nose up at statements like that.

If the quality of the information does not meet your approval, too bad. Just reading through the complete summary report, results in many reports of problems caused by passenger electronic devices.

If you want a more readable summary of the problem, read Electromagnetic Interference with Aircraft Systems.

Excerpt from the above-mentioned report:

Your linked report does offer a specific example

“There is nevertheless some experience with electromagnetic interference with electronic flight controls. Five crashes of Blackhawk helicopters shortly after their introduction into service in the late 1980’s were found to be due to electromagnetic interference from very strong radar and radio transmitters with the electronic flight control systems”

This fits perfectly well in what I would expect. If an aircraft can take bombardment from radars and ground based radios without any ill effects, why would my laptop, which isn’t designed to emit any EM transmissions (still does though), cause any problems.

" THe antennas of radio-based avionics may be affected by [electromagnetic] field intensities of only microvolts per meter. But being outside the aircraft, the antennas get some protective attenuation from the fuselage of radiation originating inside the aircraft. Non-radio systems generally have higher signal levels, and so are less susceptible to low levels of interference." (bolding mine)

Still, even the people searching for possible correlations cannot say for certain that it’s happening.

The author of the report then goes to say:

“Brunnstein is not aware of any concrete proof of electronic interference on German aircraft, but reports that EUCARE has more than 60 pilot reports of potential cases of interference, including some with cellphones. He laments the anecdotal nature of these cases, since one requirement for accurate `forensics’, as he aptly terms it, is verifiability of the source data.”

Even the anecdotes can’t agree on what is happening:

" Nordwall reports that the RTCA Committee 177 inquiry found 137 `incidents’ (pilot reports, anecdotes) reported either to them, or to the FAA/NASA Aviation Safety Reporting System (ASRS) program, or to the International Air Transport Association (IATA). VOR reception (2) was affected in 111 incidents – by far the most common occurrence. From the 33 reports direct to RTCA, 21 incidents related to laptop computers and only 2 to cellular phones. Navigation systems were affected in 26 of those incidents; fuel systems, warning lights and propulsion reported one incident each. Rough correlation of suspect with effect by turning the suspect device on and off was found in 14 cases, on-off-on in 6 cases, and no correlation in 13 cases."

And lets sum it up with this statement:

“He emphasises, as do the RTCA and the other correspondents, that more research and systematic methods of testing are urgently to figure this situation out.”

The section you quoted is immediately followed by, which you conveniently left out:

"Mchugh urges caution in interpreting the data. It has limited statistical significance because

* reporting is voluntary and there is no statistical understanding of the total reporting population or any way of estimating what the actual number of events might be;
* reporting is subjective and influenced by biases, including that reporters gain protection from FAA regulation-enforcement procedures and it is undoubtedly the case that some reports are generated mainly for that reason, and this may affect the quality of the report."

Again, all the possible evidence is anecdotal, and even that evidence cannot agree with it self. I asked you to produce some sort of scientific study with real evidence in it. Not to be a dick, but it’s time to put up or shut up.

The airlines I’ve flown with don’t allow you to use your mobile once you’ve left the terminal. (You, not the aircraft.) And then don’t allow you to use them again until you’re out of the aircraft and into the terminal again.

The pilots don’t get any particularly important comms after they’ve landed anyway.

I fly a Dash 8, and I’ve had times where we’re coming back from no-mans land outside mobile coverage, and when we get into a coverage area, the phones start communicating with the cell towers, “hello! I’m back from over the ocean, are there any messages for me? You can send phone calls my way now.” What we can hear is the “dit dit dit dit” over the intercom. If it’s just one phone, it’s annoying but no big deal, though slightly embarrasing for the guilty crew member (we don’t carry passengers), if it’s two or three then it can be quite distracting. Now I imagine that if you let every passenger on a 400 seat 747-400 leave the things on, it would be very distracting.

Everyone has a different idea of why mobiles aren’t allowed. Oddly enough, they all centre around their own little workspace. I don’t want them on because they are distracting when interfering with the radio. The flight attendant reckons it’s so people will be more likely to listen to the briefing. I would guess that the passengers don’t particularly want to have someone sitting beside them having a phone conversation throughout the flight, I know I don’t.

Yes, and I think that aircraft companies have been putting a lot more emphasis into shielding the electronics over recent years.

I am not convinced, like most of us here, that they can actually cause a problem with the navaids. I’ve left my own phone on and observed no abnormalities. If it has happened, then perhaps it requires a problem to exist with the aircraft’s wiring (say, an area where the shielding has been compromised,) already, and perhaps the phone has to be in a particular part of the cabin, who knows?

That’s a fair point. I believe that as airlines and the aircraft manufacturers get more experience with personal electronic devices, they will find that they don’t cause the problems that they feared they might, and the rules about using them will become more and more relaxed. I would still like people to turn their mobiles off though for the reasons given above.

How many dead bodies do you want to accumulate while we wait for “real evidence”?

EMI can produce false readings on instruments, disrupt communications and cause equipment malfunctions. At best, it is a distraction to the flight crew. At worst, it can cause an accident.

EMI problems can be very complex and are often difficult or impossible to reproduce. The number of variables in any given situation is large. What are the frequencies, power levels and locations of the emitters, both on-board and outside the aircraft? What are the locations and frequencies of the receivers? Where are the antennas located? What is the routing and length of the wiring? Is it shielded? Is the shielding damaged or broken? Are there corroded metal to metal contacts in the wiring or other parts of the aircraft? Are any of the electronic devices on board the aircraft damaged or defective? What’s the air temperature in the aircraft? What is the geometry of the fuselage, including holes for windows?

damn you just love your anecdotal evidence. Back in the day medicine used to work this way. thankfully evidence based medicine has caught on ans real progress is now being made.

how many bodies do i want? um, last time i checked we can build aircraft without pilots, much less passengers. using a remote controlled aircraft filled with devices that could potentially cause interference sounds like a good place to start.