Turn Off Your Cell Phone

N9472C in the air
N9472C in the air
(click to enlarge)

Every time you fly, you hear it: "You may not use your cell phone and other portable electronic devices in flight because they may interfere with the navigational equipment on this aircraft." Like me, you've probably wondered "is that really true?" An article in IEEE Spectrum by researchers at the Naval Air Warfare Center and Carnegie Mellon University delivers some surprising results.

Bill Strauss, M. Granger Morgan, Jay Apt, and Daniel D. Stancil measured the RF spectrum inside commercial aircraft cabins during 37 real flights over the course of three months in late 2003. They found that a cell phone was illegally used on average at least once per flight. In addition, at least one passenger neglects to turn off their cell phone on any given flight. They also found that cell phones and even laptops with Wi-Fi cards can interrupt the normal operation of key cockpit instruments--especially Global Positioning System (GPS) receivers. This is more than just a "navigation" issue. GPS instruments are used in instrument takeoff and landings.

The radio frequency data was collected, with the permission of the airlines and the FAA using gear concealed in a standard carry-on bag stowed in the overhead luggage bin.

Do these emissions cause problems? NASA studies have shown they do. The authors conducted statistical studies of aircraft safety databases to find incidents where interference from portable electronic devices (PED) might have been a factor.


From IEEE Spectrum: Unsafe At Any Airspeed?
Referenced Fri Mar 24 2006 15:24:12 GMT-0700 (MST)

If it's really a problem, what's to be done? Even the authors of the article admit that asking people to not use PEDs during flight isn't a reasonable alternative. They suggest steps like giving flight crews real-time monitoring capability so they know when there's problem, harmonizing emissions standards between the FAA and FCC, and continued study. In the meantime, turn off your cell phone.