MythBusters Episode 49: Cell Phones on a Plane
Air Date: March 15, 2006
You can fly with a life raft if you fill it with helium.
busted
The amount of helium required to lift a person off the ground (let alone the raft itself) is prohibitively immense, and such a raft of adequate size would be quite flimsy. In fact, the final test of the raft had to be aborted because of an unbalanced release of the ties, causing Adam to become entangled and destroying the raft in the process.
The ban on cell phones on aircraft is designed to force passengers to use the expensive in-flight phones.
busted
It was found that cell phone signals, specifically those in the 800-900 MHz range, did intefere with unshielded cockpit instrumentation. Because older aircraft with unshielded wiring can be affected, and because of the possible problems that may arise by having many airborne cell phones "seeing" multiple cell phone towers, the FCC (via enforcement through the FAA) still deems it best to err on the safe side and prohibit the use of cell phones while airborne.
Newer: Episode 50: Bullets Fired Up
Older: Episode 48: Franklin’s Kite
gps units receive radio signals, they don’t transmit them. it is transmiters that can potentially interfer with the instroments, that guy is just a wannabe geek, otherwise he’d know that.
July 16, 2007 at 5:17 PMis possible cloning a phone cellular?
August 21, 2007 at 7:57 PMThey didn’t do the cell phone myth justice? They should have gone up in the plane to test it. It is not illegal under part 91 in visual meteorological conditions. It needs retested.
September 20, 2007 at 6:38 PMhow old is the aircraft the show mentioning?
what kind of instructment are effected?
October 2, 2007 at 3:21 AMI work in the petro chemical business and we have been told that Cell phones will set off an explosion I was wondering if you have done any testing like this if so please send me the results. Thanks Harry
October 3, 2007 at 6:54 AMthere transmiiter was way to powerful, they should have used a proper phone.
November 4, 2007 at 9:17 PMI am glad to know the cell phone myth was busted. However, would someone tell the FAA and the airline industry. Last fight I took from Washington DC to Rome they feaked out over using your cell phone.
December 5, 2007 at 6:57 AMWhat about Satellite Radio receivers, like the XM Helix, on which you can listen to live XM Radio on the go?
Of course, it’s a given that you can’t listen during takeoff or landing, but still, just a thought…
January 23, 2008 at 11:56 PMCheck out the website above for a quick discussion of the technical aspects of the cellphone/plane myth as well as a critical thinking exercise.
January 25, 2008 at 10:14 AMI am retired now, but was formerly a corporate banking officer and flew frequently with customers on their private aircraft, both multiengined reciprocating, turboprops, and jets. On numerous occasions, the customer and others would be on their cell phones, talking at the same time long before we landed. It may be illegal and play hell with phone cells, but it is done constantly, frequently, and all the time. I have NEVER heard of or experienced any adverse effects to any of the aircraft involved.
January 26, 2008 at 10:21 PMI work on the electrical and avionic systems on commercial airplanes. The airplane that they tested this myth on is a late model airplane that has digital avionics with shielded data bus wiring, and I agree, should not have a problem. However, the FAA regulation is an umbrella so that analog airplanes such as the DC-9, DC-10, 737 Classics, and 747 Classics are covered. These are the airplane types that the show should have tested their signal generator on. I have been on a flight on a 737-300 where the pilot, after two PA warning announcements, stormed out of the flight deck to let the passenger see him up close and personal.
February 7, 2008 at 5:08 PMThis really needs to be retested. This doesn’t make any sense. Not to mention, don’t cell phones have a fairly limited range. 1 to 2 miles. At altitude they can’t even get a signal.
February 14, 2008 at 5:48 PMThe first comment left is RETARDED! GPS does not use a conventional radio signal, it uses a signal broadcasted by satellite. In the case of aircraft, 5 sats are used to track the aircraft. As for not transmitting, wrong again! A GPS unit must transmit a signal TO the sat for the sat to locate the unit. This is know as the UP/DOWN transmission process.
Next time you choose to open your mouth (per say), think first. Thanks.
April 8, 2009 at 2:53 PMJason:
Wrong. Check your facts again. Its called a GPS Receiver for a reason, as it only receives information. Please do some research before you call someone retarded. (Try wikipedia, or google perhaps?)
May 12, 2009 at 11:10 PMI’m glad that this myth was busted. As an airline employee,I can attest to the fact that cell-phones do interfere with flight-deck/ATC comunications. The newer planes have more advanced technology and cell-phones IN AIRPLANE MODE can be used,however, in critcal phases of flight, I.E. takeoff and landing, when ATC communication is crtical, ALL electronic devices with a possible tramsmitter signal CANNOT be used. This is not a pathetic attempt to collect more revenue, contrary to popular belief.
October 14, 2009 at 8:13 PMi’m a student pilot and even i agree with Heidi that is the real reason cell phones are turned off. I used to be the guy who was annoyed to be told to turn his cell off at takeoff/landing. Now i’m the pilot whose annoyed that he cant hear ATC or flight deck comm due to cellular interferance from my passengers(friends). It will make a overpowering squeltching noise over all communications and it makes communcation with ATC next to impossible.
October 19, 2009 at 2:09 PMThanks Heidi and Ryan for clearing it up. So i guess it’s not a death sentence if someone uses a cell phone but it’s still bad for the pilots and a good precaution to take. Cheers
November 19, 2009 at 7:23 AMHello all. I have some experience with this. I have worked on many different types of aircraft. Some believe that the signal must match a certain frequency. I am here to tell you that the only thing that needs to happen is that an aircraft internal signal be ‘disturbed’. This could affect numerous signals; autopilot or navigation. Some believe that it has something to do with communications. I know that has had some affect, but it is only a confusing matter, not a direct flight effect. Look up a Saab 340 crash in the 1999-2000 range in Europe. The pilots were on course and then suddenly off course. A cell call was made shortly after take-off and then crashed. The pilots were blamed, but they, during conversations, had no idea that their instumentation was being affected and the autopilot was just following the distorded signal that was being transmitted to the computer.
Anyhow, I wish everyone would please cut the crap about cell phone usage monopoly. I have worked for airlines and that is a hassle more than a profit. Does anyone have any idea how much it costs to approve an onboard phone system? It is very expensive. They only want to capture the installation and approval costs.
January 24, 2010 at 2:23 AMHere’s the problem. they do interfere with aircraft radios. For starters, you can hear that charactrsitc clicking in your headset, like you do when you have the cellphone active near a TV or radio, and they tend to mess with the transponders, causing them to respond to a non-existent interrrogation from a ground station.
March 28, 2010 at 11:05 AMNot an avionics engineer, but this is what thye tell me the prob is.
I don’t have any evidence either way, but I must admit that I find it very very very odd that the FAA would think there is a risk with cell phone use and then only “suggest” that we don’t use them on a flight.
May 19, 2010 at 3:02 PMI can’t get on board with toothpaste and toenail clippers, yet my cell phone affects the plane navigation system and they politely ask me not to use it?????
I’m pretty sure if there was empirical evidence, then cell phones would be clearly prohibited.
I forgot to turn my phone off once & it rang in the middle of a cross country flight. Where the phone would usually display my carrier’s name or roam, it said “Emergency”. I decided not to answer it.
June 22, 2010 at 3:52 PMJason: I am afraid that you are incorrect about your assertion that GPS units transmit to the satellite. I have been flying commercial and military aircraft for 30 years. I am also a physicist and electrical and mechanical engineer, and I have been dealing with GPS since the 1980s. The GPS units that people carry in their cars, cell phones, etc. have no capability to transmit. The receivers receive very weak signals from many satellites and calculate their position by timing how long the signal takes to arrive from each satellite. Very accurate clocks are required, and very high speed timers, to get accuracy down to as low a under a meter for unassisted GPS.
Some very specialized GPS units used for surveying actually do transmit, however not to the satellites. These units use a known position of one or more ground station (often set up by the surveyor) to correct the errors in the GPS signal from the satellite. Even WAAS receivers use this technique, but the typical WAAS receiver is still only a receiver. The WAAS GPS system uses permanent stations that transmit an additional signal to your receiver to provide corrections to the GPS satellite signal.
I think the bottom line here is pretty obvious; If it was actually possible for a cell phone to interfere with important comm or nav information on an airplane the FAA would not allow you to carry one on the plane. I don’t think that most people even know how to actually turn their phone off (many people think it is off when the screen is blank), and even I have forgotten to turn mine off more often than not. If this was a real problem then we would have incidents all the time, and we don’t.
June 24, 2010 at 5:02 PMDon’t care. Big giant pile of don’t care. I do care about the fact that if I have to sit next to you for eleven hours on a transatlantic, I do NOT want to be subject to all of your phone conversations. Even using a headset, you still have to make those annoying mouth noises while I am quietly saying my prayers that the pressurized aluminium tube we are hurdling through the sky in doesn’t drop out of the sky. (Which I do regardless of the presence or absence of cell phones.) Your iPhone has an Airplane mode. Use it, take a break from the world. Watch a movie, and fall asleep.
Seriously, I always attributed that rule a matter of enforced politeness. Not anything technical.
July 20, 2010 at 5:32 PMI accidentally left my mobile on on a flight to USA and when I arrived it had no signal and wouldn’t work. It was not blocked so I think that the aircraft or satellite transmitters had actually knocked it out.It no longer works…
August 2, 2010 at 8:02 PMMy biggest question is why do we rely on navigation technologies that can be so easily interrupted? Why not use something else that you can’t screw up with consumer electronics?
August 17, 2010 at 2:21 PM