Research Suggests Personal Electronics Could Interfere With Airplane GPS
cell phones and other personal electronic devices safe to use on airplanes?
It depends who you ask, but a new study conducted by researchers
from Carnegie Mellon University and featured in an article in technology magazine
IEEE Spectrum, says they could be.
"The data support[s] a conclusion
that continued use of portable RF-emitting [radio frequency-emitting] devices
such as cell phones will, in all likelihood, someday cause an accident by interfering
with critical cockpit instruments such as GPS receivers," the article said.
The research is believed to be the first of its kind and comes as the FCC
is soliciting opinions from the public about allowing cell phone use in airplane
The public is pushing for it, but could legalizing cell phone use
and other portable electronic devices on airplanes put passengers at risk?
Clear and Present Danger'
Air NZ to allow limited
inflight cellphone use
use of certain devices allowed
New Zealand says it will allow the limited use of cell phones in-flight following
an exemption granted by the NZ Civil Aviation Authority (CAA) relating to the
use of electronic devices in-flight.
Under this new policy, passengers
will be able to use portable electronic devices, and those mobile phones and Personal
Digital Assistants (PDAs) which can be set to a non-transmitting flight mode.
Passengers will not be able to send and receive phone calls or emailed messages
but will be able to compose email messages and use other functions enabled by
the device with the transmitting component deactivated.
Operational Standards & Safety, Captain David Morgan said the CAA still strictly
prohibits phone calls and any other transmitting functions as these may interfere
with the navigation systems of the aircraft.
"Therefore all electronic
devices and transmitting functions on these must be switched off or activated
to an in-flight mode if capable, once the aircraft door is closed. The changes
which allow the use of a mobile phone or PDA if in flight mode, apply only when
announced by cabin crew - that is, after take-off once the seat belt sign has
been extinguished and prior to the aircraft landing.
phone or other device that is capable of sending or receiving calls or sms/text
messages without this deactivating (flight mode) setting must still remain completely
switched off for the duration of the flight," said Captain Morgan.
Air New Zealand recommends that customers check their cellular and PDA devices
for "flight mode" capability prior to travel and are familiar with how
to activate this setting.
not saying we've got a crisis on our hands," said Granger Morgan, one of
the researchers. "We're
just saying that, you know, as more and more
wireless devices get on more and more airplanes, sooner or later we're going to
have a problem."
With the permission of participating airlines, which
insisted on remaining anonymous, Morgan and colleagues Bill Strauss, Jay Apt and
Daniel Stancil used a small suitcase with some technical instruments and a laptop
to monitor RF activity on 37 commercial flights.
They found that there
was indeed a lot of activity and concluded that such activity may interfere with
navigational equipment at a crucial point in a flight.
The authors point
to a NASA study that looked at the effects of a specific Samsung cell phone that
some pilots had complained had caused their onboard GPS receivers to lose satellite
"It reported that there were emissions in the GPS band capable
of causing interference," the article said. "Disturbingly, though, they
were low enough to comply with FCC emissions standards.
and the NASA studies suggest to us that there is a clear and present danger: Cell
phones can render GPS instrument useless for landings."
increasingly rely on GPS technology to aid in landings, such interference could
be potentially catastrophic.
According to the article, there are mountains
of anecdotal evidence showing electronic devices can have a dramatic effect on
"There have —
as we said in the article —
been some events that are suggestive," said Morgan. "And there have
certainly been cases where the navigation system seems to be off, and they go
back and ask somebody to turn off something and then it recovers and then they
ask him to turn it back on, and then the problem re-occurs."
As an example, Morgan and his colleagues point to an alarming incident where
the flight crew of an unnamed airline experienced a 30-degree navigational error
that was immediately corrected after a passenger turned off a DVD player.
more frightening is the fact that the error recurred when the passenger was asked
to turn the device back on.
"Game electronics and laptops have been
the culprits in other reports in which crew verified in the same way that a particular
PED [personal electronic device] caused erratic navigation indications,"
the article said.
FAA and FCC Not Talking?
In a survey the researchers
conducted with the help of a travel agent, they learned that most people believed
cell phones are illegal on airplanes to force passengers to use the seat-back
phones already on board many airliners, at bloated prices.
The truth, said
Morgan, had nothing to do with profits or safety, but everything to do with keeping
the system from overloading.
Talking on a cell phone at altitude means
you're moving from tower to tower at a rate that can cause chaos in cellular networks.
But even so, that was an Federal Communications Commission rule, not a
Federal Aviation Administration rule. And it seems that even today, the two agencies
are not communicating on what the rules for personal electronics should be.
the FCC set up to make rules, they didn't really particularly worry about airplane
interference and, you know, 30 years ago that wasn't a problem," said Morgan.
"But today, with everything in the world wireless and all of it on airplanes
all the time, it's time to start paying attention to each other and coordinating."
One of the big complaints from critics of the industry is that the two
agencies do not communicate on any meaningful level and that's led to FCC rules
that conflict with FAA interests.
In fact, former pilot and ABCNews.com
columnist John Nance, says that the first substantive communications between the
agencies was over the recent decision to consider allowing cell phone use on airplanes.
But Nance believes that as long as these devices exist and continue to
become more and more common and portable, there's no way to keep them from being
"You need to either completely and totally
ban the presence of electronics on an airplane —
which is next to impossible —
or you have to do the opposite," said Nance. "You have to guarantee
that the instrumentation cannot be affected by these signals."
There are lots of theories on how
to do that.
One of the solutions the researchers suggested was to have
an RF monitor onboard the aircraft so the flight crew can monitor activity.
flight crews or airliners had RF detectors, then they could take corrective action
when they noticed strong electromagnetic emissions," said the article.
Nance thinks the idea is original, he doesn't think it's the answer.
in the middle of a tough approach, if the RF interference really does have a potential
for messing up the GPS, you don't have time at 300 feet, at 150 miles an hour
approaching a far-shotted runway to get on the P.A. to tell people to turn off
stuff cause the RF monitor went off," he said.
Nance says you'll never
keep people from carrying and using their devices regardless of what they're told,
and instead suggests hardening the craft's avionics against any kind of interference.
"If they don't think they can do this then they'd better check with
the military, because the Navy's been doing this for years," he said. "They've
got gigantic radars they've got to protect against, they've got all sorts of RF
interference they have to harden the airplane against and all of their avionics
Though Nance admits the story about the DVD player
that affected an aircraft's GPS system gets his attention, "it's not a cell
Don't Let the Numbers Fool You
Ultimately, Morgan believes this is a cautionary tale of, "Be careful
what you wish for."
He admits that air travel has become so safe,
that researchers and safety experts are left to ponder very low-risk threats,
But Morgan says just because a cell phone call at 40,000 feet
has yet to be proven as the cause of fatal crash, doesn't mean we should be jawing
away in the skies.
"There isn't one [crash] that you can clearly nail
down, but if you're prepared to just keep on gambling, then sooner or later one
[plane] probably will fall out of the sky and I at least think it's not worth
that gamble," he said. "Low probability multiplied by a huge number
of flights will lead to accidents."