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Risk Management For Electronics on Aircraft
Phronesis writes "M. Granger Morgan and his graduate student Bill Strauss have a nice article in Issues in Science and Technology about the risks posed by electronic devices in flight. Unlike most articles on the subject, this one neither pooh-poohs the risks ('We have estimated that reported events are occurring at a rate of about 15 and perhaps as many as 25 per year') nor exaggerates them ('RF interference from consumer electronics is unlikely to have figured in more than a few percent of commercial air accidents, if any at all, during the past 10 years.'). Instead, it presents a sensible plan for dealing with the risks that will accompany the inevitable expansion of the range of electronic devices passengers will use in flight, including cell phones and wireless computer networking."
I doubt it. Most flight attendants, and people working at the airline aren't going to be on top of technology enough to know the difference.
Granted in a few years when the majority of phones are airline friendly, they will probably allow all phones to be used again with exceptions to the few people with older phones.
At least I hope they do this, it sure would be nice!
Gibble: Descriptive of an emotional state in which one's mind is scrabbling for some purchase on reality
Not only in-flight risks, but all types are discussed here. It's one of the more lucid discussions on the net. I've been following this newsgroup for the better part of 20 years.
People with pacemakers are often under doctors orders not to fly.
Airliners, as the article mentions, use microwave landing systems, etc., etc. that involve receiving signals from the outside, which cell phones could possibly interfere with.
Although there may be a small risk of a cell phone interfering with an airplane's avionics, the people complaining about cell phone use on airplanes are at the FCC, not the FAA.
See, when you're on the ground, your cell phone picks up one or two signals that have line-of-sight to where you're standing. This is how the system is designed. But at FL330, you're going to be in line-of-sight for many, many signals, and your phone will connect to all of them, essentially DoSing the cellular network. And since your cell phone transmits all sorts of identifying information when you use it, it's fairly simple to track you down.
(citation: Say Again Please: Guide to Radio Communications by Bob Gardner. Can't remember the page number ottomh)
At least here in Finland (where such phones have been available for years), it is ok to have your phone turned on in "airline mode".
My guess is that the same applies to other countries as well.
The airline steward(ess) will be knowledgeable to know which ones have such a mode
The owner of the phone will remember to actually switch modes before take-off (wouldn't it suck to have a plane crash because Bob the Executive was distracted and forgot to switch the phone to Airline mode)
Non-cellular, meaning you can use all the features, except the actual phone, so no shouting into the phone.
Disclaimer: The above comment was made while under the influence of too much coding and not enough sleep.
Some articles on a new system being introduced:
RMN
Denver Post
~afniv
"Man könnte froh sein, wenn die Luft so rein wäre wie das Bier"
Richard von Weizs
I was going to make an argument about vehicle age, but I ran out of patience. Here's some facts I've been able to glean:
For each aircraft model in commercial use in the USA, the FAA reports average ages. There are 85 different models reported, with an average (design) age of 23.5 years (not weighted by count of planes). Another site on airline safety (with counts of planes, year 2002) puts a weighted (by total planes) average of the top 14 carriers at 11.7 years. A rough guess from this is that 75% of the entire fleet is less than 13 years old (1989 with respect to the survey).
In 2001, the Department of Transportation conducted a National Household Travel Survey , which has an online query engine attached to it. From that data, I was able to find that of the reported 196.5 million cars in the USA (that the owners know the date of ownership), 75% of all cars driven in 2001 were built after 1990 (the 11 years matching the planes). 50% of all cars in use were built after 1995.
This matches fairly well with the age of planes in use, therefore age alone is not a factor. But then again, we should know that, because a plane has many different design considerations than an average car.
Incidentally, a brief history of the cellphone lists that it wasn't until 1987 that the FCC opened up the 800MHz band to digital cell phone research. Standards weren't complete until 1991, and digital PCS bandwidth was officially reserved in 1994.
You could argue that planes & cars built before that date could not take cell phone use into account. However, my gut tells me that it is the chassis of each vehicle that is the restriction... because planes are designed to be airtight, they tend to also be signal-tight Farraday cages, trapping EM inside. Secondly, cars are mostly hollow frames covered with plates and have fewer distributed sensor arrays that are critical to operation.
The problem is (mainly) not due to wiring.
The problem is in fact that the radio navagation aids 'navaids' operate at low frequencies and use geo-displacement / frequency modulation as part of the navigation method. The most common example, the VOR, or 'very high omnidirectional radial beacon' sends out a radially sweeping signal at 3600hz. This is such a low frequency that it can be affected by non-primary frequencies in small electronic devices. For example: CDMA/TDMA cellular phones, while operating at (at least one of them) 1900Mhz (AFAIK), they have polling frequencies that could be very close to 3600hz.
I would really like it if GPS was the primary navaid, but it is not. GPS was just recently approved (in the last two weeks) for IFR approaches, and until now, it wasn't even legal to conduct a full flight to commercial minimums (I think it's Category III ILS) - making it useless to commercial air carriers. Further, it's going to take the FAA at it's current rate, over a decade to convert the terrestrial navaid approaches and nav plates to include GPS routing and approaches.
Thus - here's just one example, where it's not the routing, and hopefully this will clear up the radio frequency problem... When I take off with my CFI into IFR (clouds, zero vis), I guarantee you that we both turn off our cell phones! (and that's in a 4 seater cessna 172)
Fiber is very difficult to certify for installation in aircraft due to the requirements of the physical environment. Its a challenge to get a mix of materials and connectors that survive the vibration, temperature range, and humidity requirements specified by the FAA. Its even harder to get the right mix to operate in the worst-case environment with acceptable loss.
I worked on a project to put an entertainment system that used fiber optics on planes. Although we qualified some fiber that could survive the environment, the materials that allowed it to do that failed the smoke & toxicity tests when burned. And since it was an entertainment system, we could ignore the fact that it might stop operating under some conditions - something you wouldn't want to do with critical flight control systems.
135.144 Portable electronic devices.
(a) Except as provided in paragraph (b) of this section, no person may operate, nor may any operator or pilot in command of an aircraft allow the operation of, any portable electronic device on any of the following U.S.-registered civil aircraft operating under this part.
(b) Paragraph (a) of this section does not apply to -
(1) Portable voice recorders;
(2) Hearing aids;
(3) Heart pacemakers;
(4) Electric shavers; or
(5) Any other portable electronic device that the part 119 certificate holder has determined will not cause interference with the navigation or communication system of the aircraft on which it is to be used.
Pacemakers and hearing aids have an excpeption... although I'm surprised to see that electric razors and voice recorders specifically do as well...