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'Flight Mode' May Allow Phones On Planes
14/04/2004 09:39 AM
Lucas Grinsven
The next time a flight attendant asks you to switch off that handheld computer phone, keep smiling - and pull out a copy of the latest plane safety guidelines.
Clever computer and handset makers offer an option called "flight mode," which disables the radio. As a result, the British Civil Aviation Authority has decided passengers in planes under its jurisdiction should be allowed to use these portable devices as a calendar or photo viewer because they do not interfere with the electronic circuits and radio systems used by the pilots.
The CAA says airlines should let travelers write messages, read documents and perform all other nonphone functions on phones that double up as computers, just as they can now work on a laptop, play on a GameBoy or listen to music on an iPod at cruising altitudes.
But some flight crews still fume when they spot a passenger toying with a computer phone. Airlines from no-frills JetBlue to United and British Airways have their crews scanning the aisles for them.
"How do we know which mobile is on, and which isn't?" a British Airways spokeswoman said. "It's not for our crew to decide which mobile can be switched on and which not."
In fact, the CAA says it is. Airlines would do well to train their crews to make sure "intentionally transmitting devices" like cell phones, remote control toys and two-way pagers are operated in their "safe" modes, the agency said in a recent circular.
"Any operation of these devices when the transmitter has not been turned on, should be controlled in the same manner as for any unintentionally transmitting device," the CAA added.
Unintentionally transmitting devices like radios, laptop computers and pacemakers emit negligible signals from electronics circuits.
The CAA does demand that electronics companies make it clear when the radio is turned off. Sony Ericsson's P900 smart phone, for instance, has "FLIGHT MODE" plastered over its display.
The US Federal Aviation Administration did not return calls requesting comment.
No Reason To Fear Cell Phones
In any case, flight crews are fighting a losing battle against cell phones.
About half of the world's largest airlines plan to offer wireless Internet and mobile phone access on board within two to four years, according to a survey commissioned by WirelessCabin. This consortium of large European technology companies and the German Aerospace Center is working to bring these services to planes.
"We will do a test flight (with a wireless network) on an Airbus A340-600 this summer," said Axel Jahn, a spokesman for WirelessCabin, which expects a trial run on a commercial airline next year.
Boeing Co.'s Connexion is working on a similar system.
It may be 18 to 24 months before planemakers and airlines offer such services, Jahn said, as the technology still needs licenses and approval from aviation and telecommunications regulators in Europe and North America.
The imminent approval of mobile phones on flights prompts the question whether the decade-long ban against them was ever justified.
Aviation authorities admit that mobile phone radiation poses only a modest threat. The worst incidents include setting off a false smoke alarm in the baggage compartment or interrupting communications in the flight crew headphones.
"...Many (including pilots) ... question whether a genuine problem exists," the CAA says in a cell phone safety study.
However, at maximum distance from a radio base station, say 30,000 feet above the Earth, many mobile phones will transmit at maximum power to make contact. This can disrupt a compass or a positioning system if it is 12 inches away from the phone.
The WirelessCabin systems remove that risk by putting a radio base station on board the plane. Because of its close proximity, it will force cell phones to "whisper" at 1,000th their normal output power.
"With this approach," Jahn said, "we minimize interference with the aircraft and even terrestrial networks."
As a result, flight attendants may soon shift their attention to passengers who shout into their mobile phones, interfering not with the pilot's radio system but with their fellow travelers' privacy.
