Flightfrom reality
Mobilesare barred, but passengers can lap away on their laptops to their hearts’content. Is one really safer than the other? In the US, a Congressionalsubcommittee grilled airline representatives and regulators about the issuelast month. But the committee heard that using cellphones in planes may indeedpose a risk albeit a slight one. This would seem to vindicate the treatment ofManchester oil worker Neil Whitehouse, who was sentenced last summer to a yearin jail by a British court for refusing to turn off his mobile phone on aflight home from Madrid. Although he was only typing a message to be sent on landingnot actually making a call, the court decided that hems putting the flight atrisk.
B | But despite running a number of studies, Boeing, Airbus and various government agencies haven't been able to find clear evidence of problems caused by personal electronic devices, including mobile phones. "We've done our own studies. We've found cellphones actually have no impact on the navigation system," says Maryanne Greczyn, a spokeswoman for Airbus Industries of North America in Herndon, Virginia, Not do they affect other critical systems, she says The only impact Airbus found? "Sometimes when a passenger is starting or finishing a phone call, the pilot hears a wry slight beep in the headset," she says. |
D | Many planes still use equipment certified to the older standards, says Dan Hawkes, head of avionics at the CAA's Safely Regulation Croup. The CAA study doesn't prove the equipment will actually fail when subjected to the signals, but docs show there's a danger. "We've taken some of the uncertainty out of these beliefs," he says Another study later this year will see if the cellphone signals actually cause devices to fail. |
<span style="font-family:" color:#ed7d31;"="">E | In 1996, RTCA, a consultant hired by the Federal Aviation Administration in the US to conduct tests, determined that potential problems from personal electronic devices were "low". Nevertheless, it recommended a ban on their use during "critical" periods of flight, such as take-off and landing. RTCA didn't actually test cellphones, but nevertheless recommended their wholesale ban on flights, But if "better safe than sorry" is the current policy, it's applied inconsistently, according to Marshall Cross, the chairman of Mega Wave Corporation, based in Boylston, Massachusetts. Why are cellphones outlawed when no one considers a ban on laptops? "It's like most things in life. The reason is a little bit technical, a little bit economic and a little bit political,” says Cross. |
G | There's fairly convincing anecdotal evidence that some personal electronic devices have interfered with systems. Air crew on one flight found that the autopilot was being disconnected, and narrowed the problem down to a passenger's portable computer. They could actually watch the autopilot disconnect when they switched the computer on. Boeing bought the computer, took it to the airline's labs and even tested it on an empty flight. But as with every other reported instance of interference, technicians were unable to replicate the problem. |
I | Despite the Congressional subcommittee hearings last month, no one seems to be working seriously on a technical solution that would allow passengers to use their phones. That's mostly because no one -besides cellphone users themselves-stands to gain a lot if the phones are allowed in the air. Even the cellphone companies don't want it. They are concerned that airborne signals could cause problems by flooding a number of the networks' base stations at once with the same signal This effect, called bigfooting, happens because airborne cellphone signals tend to go to many base stations at once, unlike land calls which usually go to just one or two stations. In the US, even if FAA regulations didn’t prohibit cellphones in the air, Federal Communications Commission regulations would. |
文章来源于网络，如有侵权请联系我们，将会在第一时间处理
更多资讯可以关注微信公众号：IELTSIM。
[AD] 点击此处了解【雅思合集】【学习计划定制】【终生VIP服务】
