July 12, 2005 -- -- It's like being caught by the teacher passing notes in class. All you want to do is call your neighbor to make sure the sprinkler's off, but suddenly a flight attendant materializes beside your seat ordering you to turn off your cell phone.
"Why?" you ask, as politely as possible, clumsily jabbing the off button while your neighbor back home answers a dead line. You know the phone only puts out a fraction of a watt of radio energy that couldn't heat up a gnat.
"Because," the flight attendant replies, "it interferes with the navigation equipment of this aircraft."
Is the flight attendant right?
Well, it's certainly true that all flight attendants in North America have been told cell phones can interfere, and their procedures leave no wiggle room as to when all those pesky phones have to be off. In addition, you'll find many pilots absolutely convinced (without evidence) that cell phones can interfere with the instruments up front in the cockpit, and you'll find others outside the industry equally convinced that cell phones are flatly dangerous to the safety of big air machines.
But in reality, there is no proof that it's true. In fact, something the U.S. government is about to do completely invalidates the fears of the past.
The subject of airborne cell phones and alleged interference has become hopelessly mired in a combination of mythology and unsubstantiated allegations -- not the least of which is the urban legend that the airlines ban airborne cell phone usage to force you to use their expensive seatback phones (not true).
Here's what's really going on.
First, two major federal agencies got confused early on about who should decide the issue. In the mid-'80s, when cell phones were the size of a brick and put out a far more powerful analog signal, the Federal Aviation Administration expected the Federal Communications Commission to answer whether such signals could interfere with the instruments in an airliner. The FCC, however, tossed the ball right back to the FAA, saying it was an air safety issue it wasn't equipped to research. In the meantime, more of us cellular pioneer users were happily dialing up from our window seat at altitude, only to get hit with a bill at the end of the moth featuring multiple "access" roaming charges of $3 apiece because our airborne signal had been latching onto and then jumping away from dozens of cell phone towers on the ground below.
Because cell phone technology relies on a grid of low-powered transmitting sites which hand off the radio signals of cell phones moving through that grid, the system "expects" your cell phone to be transmitting from ground level with the signal fading from one location as it intensifies at another. If, however, all the cell site towers in a particular city (for instance) start picking up your cell phone signal at the same strength level because it's coming from above, it confuses the heck out of the computerized circuits. The cell system starts rapidly handing the call back and forth among the different cell towers, taking up bandwidth and causing problems. The cellular companies didn't like this, and neither did the FCC, so cell phone usage in the air was in essence banned, and the cellular companies adjusted their towers to reject airborne calls.
The airline industry, meanwhile, became frustrated that the FAA wasn't telling it what to do on the issue. So in the absence of an FAA rule, the airlines reasonably erred on the side of caution and banned airborne cell usage themselves.
But then it began to get silly, because the flight attendants who had to enforce the rules were never told the truth about why the ban was instituted, and they began to believe the signals really could interfere. Flight attendants began fighting cell phones at the gate, in the jetway and on taxi-in with a deep intensity born of lack of understanding -- as if the plane might actually explode if someone made an illicit call. There was, in fact, a great amount of stress and unnecessary anxiety inflicted on the cabin crews, and even on the passengers.
Of course, to the rest of us, the idea that a cell call could interfere with a crew taxiing an airliner to the gate after landing on a clear day was, to be charitable, suspicious. But rules are rules.
In reality, no testing done to date has ever validated the idea that modern cockpits can in any way be affected by even a cabin full of active cell phones, especially not while on the ground (with or without the door closed). Even more scary, though, is the reality that if these claims had been true, why would we ever have allowed cell phones with batteries attached into the cabin in the first place? The contradiction was, and is, massive -- and frankly, embarrassing.
Now, however, the FCC and FAA are at long last cooperating with the industry on how and when to approve the use of real cell phones in flight. True, they won't be sending their signals directly to cell tower grids on the ground, because those systems won't accept airborne calls any more. But we're talking about your phone, at your seat, used at your discretion for a moderate per-minute fee charged to your own cellular bill. How? An onboard system will collect all the active cell call signals, reprocess them through a satellite system and feed them into a ground system. And, yes, that's the same cell phone that last year (supposedly) had the potential to create a major airline accident.
In other words, what the FAA and FCC are seriously considering will be irrefutable proof that there never was a real threat to begin with, and they've dropped the ball for 20 years on reaching this backdoor conclusion.
But remember, until those new systems are approved, the same rules apply and we must all honor them until changed: No cell phone usage after the doors are closed until taxi-in. We now know it's technically unnecessary, but at least now you know why.