High Flying Cell

I wrote about this sort of issue a couple of years ago, and I’m not surprised to see that some people still don’t understand not to use their cell phones on airplanes when told not to.  Perhaps it’s because some think it’s some sort of conspiracy to make you use overpriced air phones, or that others think that the FAA is being overly cautious. 

In the this latest incident, a man was given a citation for disorderly conduct because he wouldn’t get off the phone while the plane was landing.  In this case, he’s claiming that it was a “life or death” situation:

A Southwest Airlines passenger was cited by police Monday for refusing to stop talking on his cell phone during a flight from Austin.

Police were summoned by Southwest officials and met the plane when it arrived at Love Field. Joe David Jones, 50, of Austin was ticketed for disorderly conduct, police said.

But FOX 4 found out that Jones had just learned his father’s heart had stopped and he was trying to give instructions for his care.

Jones’ Austin company, Skyonic Corporation, made the following statement:

“While his plane was descending into Dallas, Mr. Jones received a message on his phone that his father’s heart had stopped beating and the hospital cardiac unit needed to speak with him immediately to make decisions regarding his fathers immediate care and resuscitation.  Mr. Jones made several attempts to call the cardiac unit prior to his success.  Upon arrival at Dallas, Mr. Jones received a citation and was released.  Mr. Jones regrets any inconvenience that his actions caused the airline or his fellow passengers but felt compelled, due to the life-and-death nature of the problem, to act as he did.  Mr. Jones is on his way to his father’s side.”

As much as it may be tempting to feel sympathy to Mr. Jones, I’m going to have to call bulls**t on this one.  First, if he’d been following the rules like he was supposed to, he would not have received the initial message.  Second, if his father was that sick, he should have known that something like this could happen.  His claim that he had to make “immediate” decisions about his father’s immediate care and resuscitation indicates a lack of planning on his part.  It’s nearly inconceivable for me to think that someone could go away in such a situation without having given instructions before hand if his father was already in the cardiac unit. 

It seems to me that we’ve become so accustomed to being instantly connected that we can’t deal with disconnected time, so everyone is tempted to think that he or she can get away with it just this one time, especially since most people don’t understand RF or electronics. 

As mentioned in the EMI study that I linked in my previous entry, cell phones on airplanes do appear to have the ability to affect aircraft systems in some cases.

Here’s one from a B737 (FYI—Southwest flies 737’s):

[…] One day departing Portland Oregon we noted that the FMC [Flight Management Computer] Map display showed a disagreement with the “raw data” VOR position. Our training is such that we would normally immediately switch over to “raw data” and assume the FMC was in error.
We would have done that except that it was a beautifully clear day and I looked out the window and was able to determine that the FMC seemed to be               right on. I called back to the cabin and asked the flight attendants to check for someone using a cell phone or computer. A few minutes later they               called back to say that a man had been using his cell phone and it was now off. Strangely (?) our VOR and FMC map now agreed.
Later in the flight the flight attendants called back and said that they had caught the man using his cell phone again but this time we had not               noticed any problems, perhaps because we were in cruise far from the ground and not paying as much attention.

Another 737:

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.

So, the next time the flight attendant asks you to turn off your phone, they’re not doing it to personally inconvenience you.  They’re doing it for the safety of the aircraft and everyone on it. 


  1. Phelps says:

    Anecdotes alone are not data.

    And given all the garbage in our airwaves, if cell phones are able to jigger with the electronics, then we need to look at better shielding and error correction, not turning off all the transmitters we can and hoping for the best.

    (I’ll still turn my cell phone off because I like the peace and quiet.)

  2. No, anecdotes alone are not data.  But due to extreme caution, no one has done a lot of direct study on this (which is understandable).

    Note that this type of interference is most likely due to the fact that the cell phone is inside the plane.  The metal skin of the plane serves as a block to a lot of external RF, but at the same time serves to trap the cell phone’s RF inside.

    Shielding is a nice idea, and perhaps someday we’ll come up with something foolproof.  But RF is pernicious stuff, and it’ll sneak in or out of the tiniest crack.  All it takes is one connector that’s slightly loose or that’s been banged up one too many times.  It’s not enough to directly affect the given circuit, but it could be enough to let in external RF.

    As we see newer aircraft begin to be fitted with micro cells to allow inflight use of cell phones, perhaps shielding will get better (and we’ll probably see some interesting interactions in the interim; although with the micro cell the power levels will be a lot lower, reducing some of the risk).  But I’m not too interested in being a guinea pig during that interim period, either.

    It’s still best to turn everything off during the critical phases of flight.

  3. Phelps says:

    The navigation antennas are on the outside of the plane.  That kinda kills the “skin as a block” theory.

    The cells within the plane will end the problem, I think, but for a different reason; the engineers will have to build “cell phone interference” into their spec, and stop with the “I’m going to stick my fingers in my ears and sing lalalalala” plan they are going with now.

  4. Sure, the nav antennas are on the outside of the plane.  And the nav devices are designed to reject spurious signals on their inputs.  But did you stop to think about all of the other connectors and devices INSIDE the plane that may not be as hardened as they should be?  Or that over time have had their shielding deteriorate?

    Further, what makes you think the engineers are sticking their fingers in their ears and going “lalalala”?  Aircraft do have to go through quite a bit of RF analysis and shielding.  But that’s predicated on the assumption that no idiot on board is transmitting.  Now, with the proliferation of handheld RF emitters that’s no longer valid.  But it’s going to take a while to fix this.

    Anyhow, I’m not an RF engineer, but I have studied physics along with wave motion and I’m an amateur radio operator, so I’ve had to learn a few things about RF propagation and shielding along the way.  I know just enough to know that I don’t want some dingleberry fraking around on his crackberry during flight.  And it will take a lot of technological advancement in flight systems before I’d be comfortable with it.

  5. Phelps says:

    Further, what makes you think the engineers are sticking their fingers in their ears and going “lalalala”?

    Because the engineering is:

    predicated on the assumption that no idiot on board is transmitting.

    I’m not an RF engineer either, but I have done monkey work for them and had an RP license.  I think that the FCC dropped that requirement for commercial broadcasters right after I got it.  I know that only the chief had to have a First Class.

  6. I think it a rather unfair assessment to call it ‘lalala’ engineering just because of the original assumptions.  It’s not like they’re doing nothing, as you would assume.

  7. Mike5906 says:

    While I agree that we need to follow the rules and regulations that are set in place, I do not agree with your reasoning on this.  I turn my iPhone’s airplane mode on while on the plane, becasue the law says so.  That’s the only reason.

    As for the technical reasons, they are 100% BS.  Period.  There is absolutely zero reason to worry about RF interference on a plane.  Europe came to that conclusion a long time ago.

    There are two reasons that cell phone use is not allowed on planes.  1) to drive up the use of on-board pay-per-minute-rediculous rate phones, and 2) the cell phone companies don’t like the phones above the towers spamming 30 towers at time rather than just two or three.

    If you think for more than 1 second that at least half the people on a plane actually turn their phones off your kidding yourself.  I fly often enough to know that at least half the people do NOT turn off their phones, EVER.  And we don’t have planes falling out of the sky or crashing on take off or landing.  That’s proof enough that there is no issue.

  8. Mike,

    I disagree on your conclusion that it’s conclusive proof that there “is no issue.”  Just like Phelps’ admonishment of me that anecdotes are not data, I would suggest you consider the same.

    I would suggest that just because planes haven’t been “falling out of the sky” doesn’t mean that it can’t happen or that it didn’t happen and the pilots simply used a backup system. 

    I think we need to see some additional studies before anyone can state conclusively that RF interference is 100% BS.