For many of us, the prospect of spending time trapped in an airline cabin listening to a passenger chatter into a cell phone may evoke thoughts of a 1950s horror-movie-like title: "Cell Phone Hell at 33,000 Feet!" Despite the current ban on cellular telephony, that possibility came a bit closer to reality in late 2004, when the U.S. Federal Communications Commission began reviewing a proposed regulation that would permit the use of cell phones in flight. Although no decision date has been set, telecommunications companies and some airlines are champing at the bit to provide these wireless services.
But beyond the anticipation of dollar signs and aural torture to come, recent research indicates that there may be sound safety reasons to continue the existing FCC and Federal Aviation Administration prohibitions on cell phone use in the air.
Experts have debated for years whether it is safe to use cell phones and personal electronic devices (PEDs) such as laptop computers and gaming devices on airplanes. Although crews have submitted numerous reports of errors in avionics (electronic navigation, communications and flight management) systems that ceased after all PEDs were shut down, many specialists consider this evidence to be anecdotal. Further, skeptics doubt that any interference from these devices would lead to mishaps, particularly if they were deactivated during takeoffs and landings. After all, no air accident or near miss has been definitively attributed to radio emissions from PEDs. When confronted with such data in the past, the airline industry has simply responded by installing better shielding around avionics systems and adopting other mitigation strategies.
Recently, however, researchers at Carnegie Mellon University concluded that cell phones and other PEDs could endanger the normal operation of critical navigation systems on aircraft. After monitoring radio emissions from portable electronics during airline flights (with an antenna and spectrum analyzer that fit into a carry-on bag), they estimate that an average of one to four cellular calls are made from the cabin during each trip--despite the ban. The researchers also determined that some of the emissions from mobile phones occurred in frequencies employed by Global Positioning System (GPS) receivers, which are increasingly vital for safe landings. In addition, the study warned that avionics that operate at non-cell phone frequencies could encounter interference when nearby wireless signals interact and generate spurious spikes in other frequency ranges.
Given the new research, we recommend that further study be performed before lifting the in-flight prohibition of cell phones. First, the aviation agencies should collect more complete data on aerial wireless-interference incidents. Next, the government should enlist a competent technical organization to characterize the onboard radio-frequency environment more accurately. The aviation industry, the FCC and the FAA should also better coordinate their risk analyses of mobile phone use. Finally, the FAA and the airlines should attempt to convince the flying public that restrictions on the operation of electronic devices are enforced to reduce real safety risks, not to gain some commercial advantage such as protecting existing Airfone-type in-flight phone services.
Being trapped on a plane with cell phone junkies is one thing, but the possibility that their calls could cause a crash is an issue no one should take lightly.