Sit Down, Shut Up, And Enjoy Your Flight

It seems that some animals think they’re more equal than others and their arrogance might end up getting someone killed one of these days.

You might want to think twice the next time you’re tempted to make a call from your cell phone during an airplane flight. Or flip on your portable game player. Or work a spreadsheet on your laptop.

Besides possibly annoying fellow travelers and breaking federal regulations, you might be endangering the airplane, according to a Carnegie Mellon University study that quietly monitored transmissions on board a number of flights in the Northeast.

The study, by CMU’s Department of Engineering and Public Policy, found that the use of cell phones and other portable electronic devices can interfere with the normal operation of critical airline components, even more so than previously believed.

Now we’ve all heard the announcements to turn off and put away “all portable electronic devices” during takeoff and landing.  And we’ve all seen people who can’t be arsed to follow the rules.  The majority of the time they get away with it.  And from the article, it seems to happen quite a bit:

And despite the ban on cell phone use during flights, the researchers discovered that on average one to four cell phone calls are made from every commercial flight in the northeast United States.

Some are even made during critical flight times, such as the climb after takeoff or the final approach.

The Slashdot discussion had an interesting link to an EMI study that attempted to analyze the reasons for interference.  Unfortunately, there is not good data available, and the incidents are hard to reproduce.  But while the article above talks about GPS, GPS isn’t really the main concern.  There are a lot of more important systems on board that could potentially be affected, as this quote shows:

April 30, 1997. B737-400: During level cruise, the AP pitched up and down with ROC/ROD of 400 fpm indicated. Other AP was selected: no change. Cabin was checked for PC’s and other electronic devices: nothing was found. Requested passengers to verify that their mobile phone (GSM) was switched OFF. Soon after this request all pitch oscillations stopped.

The problem here is that all these devices haven’t been tested on airplanes and to do so would be a monumental undertaking, as it’s not just intentional radiators, like cell phones, but other devices that are unintentional radiators that must be tested.  Further, it’s nearly impossible to guarantee that any particular instance of a class of device still complies to standards after it’s been dropped, kicked, bitten, stepped on, and otherwise abused by its owner.  While we expect airplanes to be resistant to EMI/RF, and they are tested for this, there are still many situations that could lead to sensitivity.  An example given in the above study is that connectors are especially susceptible to RF leakage, especially after repeated maintenance.  Further, since the skin and framework of the aircraft are metal, they could act as an amplifier for an ill-behaved device (or even a well-behaved one in unforseen circumstances).  Heck, even devices that have been certified according to the existing standards can sometimes interfere with each other unintentionally (i.e. through harmonics of internal oscillators, etc). 

It seems to me that we’d have to engineer airplanes with a whole new level of RF interference standards before we allow cell phones to be used onboard.  I’d consider any existing design to be unready for the challenge.

In the meantime, I have an idea for a way to protect airplanes from this sort of problem.  It might prove too expensive, but I can envision a set of RF detectors stationed strategically throughout the aircraft cabin and wired into a central control system.  Using relative signal strengths, the system could determine the location of any RF radiator in the cabin down to a small section of the cabin (perhaps two or three rows, or even one row if you have enough sensors).  If the system were sufficiently foolproof, it could even activate a small light above the offending row or rows.  Or if you wanted to make it unpleasant to ignore the rules, have the system sound an alarm and flash a light over the row in question.  It would then immediately become obvious who was trying to use a cell phone (or even some other RF-emitting device).

If the above is too much, then one could perhaps implement a rule that if a passenger is observed using any sort of transmitter (cell phone, FRS, Gameboy, etc) and there is interference observed with the plane’s systems on that flight, then that passenger must stay behind and cooperate with troubleshooting activities with the flight and maintenance crews.  I suspect after a few of these self-important bastards are made to spend several hours “cooperating,” they might think twice about breaking the rules (as these types of people always regard their time as more important than that of others).

Anyhow, it seems to me that there isn’t anything so urgent that it can’t keep until the plane lands, except for emergencies, in which case the rules are out the window (as we saw on 9/11 with people calling from cell phones).  But frankly, airplanes are so damned cramped (at least back in steerage where I usually travel), that it’d be intolerable to have to listen to someone babbling on a cell phone.  I like the idea of the Amtrak Quiet Car that one Slashdot commenter mentioned.  Sit down, shut up, and enjoy the view!

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