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Q: Do Cell Phones work from jets above 30 000 feet? ( Answered 4 out of 5 stars,   2 Comments )
Subject: Do Cell Phones work from jets above 30 000 feet?
Category: Science > Technology
Asked by: latelyirish-ga
List Price: $100.00
Posted: 07 Mar 2003 01:47 PST
Expires: 06 Apr 2003 01:47 PST
Question ID: 173057
The claim has been made that the Flight 93 cell phone calls have to be
a hoax.  They were reported by CNN as occurring (at least initially)
when the plane was  at 38,000 feet.  Prof A K Dewdney says he has
conducted an experiment showing that commercial cell phones do not
work above 8000 feet, even over an area highly populated with cell
masts etcetera.  Is he correct?
Subject: Re: Do Cell Phones work from jets above 30 000 feet?
Answered By: rainbow-ga on 07 Mar 2003 14:41 PST
Rated:4 out of 5 stars
Hello latelyirish,

Thank you for the opportunity to answer such an interesting question.

After researching this question extensively, I have been able to
establish that cell phones do work from airborne planes.

Airlines in the US follow and strictly impose the Federal
Communications Commission (FCC) regulation 47 CFR Ch.1 (10/01/98
Edition) which states:

“Section 22.925 Prohibition on airborne operation of cellular
telephones installed in or carried aboard airplanes, balloons or any
other type of aircraft must not be operated while such aircraft are
airborne (not touching the ground). When any aircraft leaves the
ground, all cellular telephones on board that aircraft must be turned
off. The following notice must be posted on or near each cellular
telephone installed in any aircraft: The user of cellular telephones
while this aircraft is airborne is prohibited by FCC rules, and the
violation of this rule could result in suspension of service and/or a
fine. The user of cellular telephones while this aircraft is on the
ground is subject to FAA (Federal Aviation Administration)


The same regulation can be found at the following site:
‘Using Cell Phones While Flying’

The FCC rule, 47 CFR 22.925, prohibits the use of cell phones after
the aircraft leaves the ground. This rule applies to all aircraft
whether commercial or private or whether powered or simply a balloon.
The FCC rule applies only to cell phones. It does not apply to other
PEDs (Portable Electronic Devices). This rule was adopted in December
1991. It was based on the Commission’s concern that use of cell phones
in the air could interfere with the cell phone system on the ground.

“A cell phone signal from the ground transmits only to one cell base
station. However, from an aircraft at 30,000 feet, cell phone signals
reach the earth in a wide cone that covers many receiving stations.
This could undermine the radio traffic management system and interfere
with other calls.”

Source: The Subcommittee on Aviation Hearing on Portable Electronic
‘Do they really pose a safety hazard on aircraft.’
United States House of Representatives

There is much discussion concerning the validity of the above
regulation. The following excerpt relates specifically to United
Airlines Flight 93 and refers to FAA rules prohibiting the use of
cellular phones once on board the aircraft.

“… Cellular networks may even have saved lives in other ways. We'll
never know exactly what happened on board the four hijacked airliners,
but we do know that some passengers used their cell phones to call
family or emergency services.
On United Airlines Flight 93, the last to be hijacked, communications
networks did more than enable people to hear a friendly voice in their
final moments…”
“… The real heroes are the passengers of course, not the technology
they used, but the events have affected public attitude toward
wireless technology nonetheless. Previously seen as nuisances, cell
phones are increasingly regarded as potential lifesavers…
Many frequent fliers would also like to use cell phones on planes, but
airlines are unlikely to comply. Current FAA rules only let passengers
make calls while their plane is docked at a terminal gate. They must
switch off once the doors are closed. Similar regulations apply abroad
and in international airspace, though no cell phone will work over the
oceans anyway.
Contrary to popular belief, in-flight cell phone use isn't banned
because it interferes with navigation systems. It's banned because a
phone at high altitudes will try to connect with many base stations at
“In an emergency, passengers will (quite rightly) ignore FAA rules and
use cell phones anyway. But at present, 911 operators have no way of
knowing whether a caller is even on a plane: There have already been
hoax calls made by phone thieves on the ground, who can now scramble
the Air Force by pretending to report a hijack.
Location technology would prevent this: It can't measure altitude, but
it can infer whether someone is on a plane by calculating their

Source: ‘Did Cell Phones Save the White House?’
CommWeb – Where Telecom, Datacom and the Internet Converge

All the evidence points to the fact that cellular phones actually
work, with varying degrees of reliability, in airplanes. As stated
below, again referring to the hijacked United Airlines Flight 93, the
FBI has evidence of cell phone conversations made between passengers
on the flight and people on the ground:

“The Federal Bureau of Investigation (FBI) knows from witness accounts
of cell phone conversations with passengers on the hijacked airliners
that the terrorists eluded security measures and used cardboard-box
cutters and razors to take control of the four aircrafts…
United Airlines Flight 93 was airborne by 8:44 a.m., according to
radar logs. At 9:37 a.m., the plane turned south and headed back the
way it came…
Passengers on cell phones learned of the crashes at the World Trade
Center and formulated a plan to respond to the hijackers.”

Source: ‘The Network of Terrorism – The Hijackings’
US Info – International Information Programs

The following are some references of cell phone conversations being
made by passengers on the hijacked airplanes on 9/11.

‘FBI lets Flight 93 families hear tape’
The Washington Times

A report from The Associated Press

WWNF Sept11



American Memorials

Like the experiment conducted by Prof A.K. Dewdney mentioned in your
question, there will be references to research being made which may
imply that cellular phones cannot work at high altitudes. However, the
overwhelming evidence supported by credible authorities as
demonstrated above proves that cell phones do work at high altitudes.

Search terms used:

cell phones flight
cell phones flight altitude
cell phones airplanes altitude
Prof A K Dewdney
FCC cell phones regulations airplane
Flight 93 cellular phone calls
Cell phones aircraft
9/11 cell phone calls

I hope the information I have provided for you is helpful. If you have
any questions regarding my answer, please don’t hesitate asking before
Best regards,

Clarification of Answer by rainbow-ga on 08 Mar 2003 10:45 PST
Hi latelyirish,

Thank you for your kind comment. I assure you that any
misinterpretation of your requirement for specific technical data
substantiating or disproving Prof. A.K. Dewdney’s findings was
unintended. As you have observed, I limited my research to
establishing whether or not cell phones can work at altitude.

With regards to the problems you are facing with your password, may I
suggest that you contact Google Support who will be able to help you.
The email address is

Best regards, 

Clarification of Answer by rainbow-ga on 09 Mar 2003 10:35 PST
Hi latelyirish,
Thank you for the rating and generous tip. It was a pleasure working with you.
Best regards,
latelyirish-ga rated this answer:4 out of 5 stars and gave an additional tip of: $20.00
It's interesting at least to know that the researcher didn't easily
find evidence of high-altitude cell calls other than the 9-11 case -
neither could I, nor could I get my own phone to work at altitude,
which of course could be a fluke.

I would have thought that people agitating to allow cell usage on
planes would have experimented to see exactly how useful it would be. 
Seems not?

Finally, I would have thought that there must be thousands of telecom
engineers who could give a direct and categorical technical answer to
this question - this is what I really sought.

I assumed Dewdney's allegation would be trivially debunked, and that
there must be technically authoritative web pages doing so.  Seems

Subject: Re: Do Cell Phones work from jets above 30 000 feet?
From: latelyirish2-ga on 08 Mar 2003 00:21 PST
Hi Rainbow

I'll give you an A for effort, and therefore have no objection to

However, what I wanted was technical data, not the 9-11 call reports,
that shows that cellphones work at speed at 30,000+ feet.  If one of
your links showed this, I missed it - I just see rules against using
them, and the 9-11 accounts, which is exactly what I found when I
researched this myself, and is why I posted the question here.

I'll post the question again, clarifying the above, (and maybe up the
price - I'm quite curious).

The reason I'm putting this as a Comment, is that I can no longer log
in to Google answers using my original mail address (in spite of twice
having reset the password, although I was sure I hadn't forgotten it).
 So I had to create a new account with a different mail address.  (No,
I don't think it's a conspiracy <grin>).

Thanks much
Subject: Re: Do Cell Phones work from jets above 30 000 feet?
From: karlon-ga on 25 Mar 2003 15:21 PST
Does this help?


Cell phones work on airplanes? Why does the FAA discourage their use?
What's the maximum altitude at which a cell phone will work?

From this morning's New York Times: "According to industry experts, it
is possible to use cell phones with varying success during the ascent
and descent of commercial airline flights, although the difficulty of
maintaining a signal appears to increase as planes gain altitude. Some
older phones, which have stronger transmitters and operate on analog
networks, can be used at a maximum altitude of 10 miles, while phones
on newer digital systems can work at altitudes of 5 to 6 miles. A
typical airline cruising altitude would be 35,000 feet, or about 6.6

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