Slashdot Mirror
FAA To Reevaluate Inflight Electronic Device Use
coondoggie writes "If you have been on a commercial airline, the phrase 'The use of any portable electronic equipment while the aircraft is taxiing, during takeoff and climb, or during approach and landing,' is as ubiquitous but not quite as tedious as 'make sure your tray tables are in the secure locked upright position.' But the electronic equipment restrictions may change. The Federal Aviation Administration today said it was forming a government-industry group to study the current portable electronic device use policies commercial aviation use to determine when these devices can be used safely during flight."
Because the reason they are banned isn't because of electromagnetic emissions, but rather because it is a crowd control technique. There's nothing special about the first 10 and last 10 minutes of a flight, other than it's the most likely time for a plane to crash land. The regulation is all about causing passengers to pay attention to flight attendants and nothing to do with avionics.
Didn't Mythbusters cover this?
Yes.
Ceci n'est pas un sig.
Second paragraph in the article. "The group however will not "consider the airborne use of cell phones for voice communications during flight.""
There's nothing special about the first 10 and last 10 minutes of a flight, other than it's the most likely time for a plane to crash land.
Actually, that's exactly what's special about those times.
Unix is user friendly, it's just selective about who its friends are.
This is why on aircraft that are licensed to allow cell phone use carry their own femtocell style access points. There aren't many airlines/aircraft that are licensed, but the trials have been in place for some time.
The main problem with cell phones on planes is a customer problem: the cost. They charge at international roaming rates, so it's not worth it unless you're making money off the call.
Your airplane contained a microcell and wifi base station. This reduces the transmitter power concerns because the mobile unit is able to reduce power because it's close to the base station. It also resolves the problem of a phone being present in many ground cells at once, since the mobile unit instead connects to the aircraft-based cell.
The most popular provider of inflight wifi in the US is Gogo, which uses a ground-based network of CDMA transmitters to link the aircraft's wifi base station with the Internet.
End of Line.
-Shades up so other planes can see you better while you are on the ground at night
I haven't heard this reason before, and if you think about it, dedicated freighters don't have passenger windows at all for light to escape through.
One explanation that I have heard is that having the shades open provides better situational awareness during the critical landing and takeoff phases of fight. Suppose the port side engine catches fire. With the shades open, people will see this and the flight attendants will know to direct passengers to evacuate using the starboard side exits only.
End of Line.
Cell phone do not interfere with airplane equipment. Totally different frequency bands. Cell phones are used on planes (surreptitiously) every day. Occasionally and angry stewardess, but no other ill effects.
Cell phones are not allowed on planes at the behest of the FCC, because the cell systems we use today were never designed for hand off calls over vast regions at the speed of a plane, and a phone at cruise altitude could light up a thousand towers. This prohibition was always an FCC issue, and never much of a concern for the FAA.
WIFI would be just as likely to interfere as would cellular radio.
Yet wifi on the planes is already available on many flights.
With wifi, you can do voip. Almost every Android phone has Voip (internet calling) built in.
As of this time, none of the airlines allowing WIFI let you use any Voice app. They claim bandwidth issues.
However voice does not take as much bandwidth as most people think.
I suspect there is still some security concerns with allowing voice communications that are the real hold up here, I doubt there are any real technological issues in providing the bandwidth. On the other hand they do allow text chat apps, as well as email.
Sig Battery depleted. Reverting to safe mode.
If your phone can connect to a tower 32,000’ away including all the scattering that buildings cause then there's no reason why it couldn't just because the signal is travelling in a more perpendicular direction with no obstacles.
Cellular antennas are optimized to receive signals in a horizontal "circle" parallel to the ground, so reception above/below a tower is poor.
If you're in the air, you're not connecting to a tower 32,000' below you, you're connecting to a whole bunch of towers 32,000' feet below you and 20+ miles away. Cellular signals will actually go pretty far with clear LOS, although the phone has to up the signal strength quite a bit, which is why a phone with a cellular antenna left on in-flight will burn a ton of battery.
paintball
I sat next to a relief pilot on a United flight from PHX to SFO. He talked on his cell phone from the moment we got on, until he lost his signal after takeoff. As soon as he got a signal again, he was talking all through the approach and landing. He still had it stuck to his ear as we walked off the plane. The cabin crew didn't say a word to him.
Actually, the receiver will generate very low level signals that propagate out from the device as part of the Rx circuits. This is no big deal - unless your GPS is in your pocket, you're in the window seat, and the plane's GPS receiver is mounted between the plastic interior skin and the outer aluminum skin (what, you thought the plane's GPS RF section was in the cockpit?). Your GPS receiver will be putting out a tiny signal, but it may still swamp the signal being received from the satellites 12,000 miles (20000 km) away.
For example, there was a report to the NASA pilot safety program:
"In 2007, one pilot recounted an instance when the navigational equipment on his Boeing 737 had failed after takeoff. A flight attendant told a passenger to turn off a hand-held GPS device and the problem on the flight deck went away." (http://www.nytimes.com/2011/01/18/business/18devices.html). This is apocryphal, and even if true would likely be the result of a badly damaged or badly designed device that didn't meet FCC regulations - but if you're going to allow a million people to carry on any electronic device they might have, in whatever condition it might be in, you're going to run into these kinds of receive-only-devices-that-transmit-worrisome-amounts-of-unexpected_RF.
This (http://gpsinformation.net/airgps/gsm_intf1.pdf) discusses the likely interference caused by phones in an aircraft; the big worry isn't so much modern planes and electronics, as it is electronics and planes designed before 1984:
"From the above, by comparing the test results with the qualification levels given in Section 2, it
can be seen that interference levels produced by a portable telephone, used near the flight deck or
avionics equipment bay, will exceed demonstrated susceptibility levels for equipment qualified to
standards published prior to July 1984. Since equipment qualified to these standards are installed in older
aircraft, and can be installed (and is known to be installed) in newly built aircraft, current policy for
restricting the use of portable telephones on all aircraft will need to remain in force." Of course, this document is 12 years old now, discussing designs that were current 16 years previously.
And the worms ate into his brain.