Why airlines don't allow cell phones

The Federal Aviation Administration (FAA) just announced that most electronic devices can now be used on airplanes, all the way from takeoff to landing. But you still can't make a call on your cell phone during a flight, and all devices must be set to "flight mode." Why can't you make calls on flights? To get a better understanding, let's use some trigonometry.



Airplanes communicate and navigate using a band of radio waves called the airband, which uses frequencies between 108 and 137 MHz (or megahertz). Radio waves are electromagnetic waves, or waves of light, which travel through space like the sine function. Waves with higher frequencies move up and down, or "oscillate," faster, while lower-frequency waves oscillate more slowly. Here are examples of waves that have different frequencies:


How do the frequencies of cell phones compare to those of the airband? Well, it depends on the carrier (Verizon, AT&T, etc.), but for the most part they're between 500 and 2500 MHz. So cell phones send and receive radio waves that are close to the Airband, but are slightly higher in frequency.

If you were to make a call on a plane, then the cell phone's radio waves and the airplane's radio waves would add together. The airplane's waves are probably a lot stronger than the waves coming out of your phone. So what happens if we add a very weak cell phone signal (say, at 700 MHz) to a strong airplane signal at 120 MHz?


The sum of the two waves looks pretty close to the airplane's signal. But what happens if the cell phone signal were a lot stronger?


Suddenly, the sum looks quite different from the airplane's signal, and that's what worries the FAA. While there are mathematical tools that tease apart signals with different frequencies that have been added together, pilots and officials are concerned that cell phone radio waves could still interfere with the communication and navigation of airplanes.

If cell phones instead used frequencies that were really far away from the airband, then the risk of interference would be even smaller (even if the phones emitted really strong signals). Why do you think that is?

7 comments:

  1. This is a very serious matter you rise here, When ever i travel to airplane, I also don't take my laptop with me and due to this pay to do an assignment, This is only for safety.

    ReplyDelete
  2. This is a really significant issue that you raise. I always bring my phone when I fly, and I do it mainly out of concern for my safety.

    ReplyDelete
  3. You raise a really important point here. When I fly, I always bring my phone, primarily out of worry for my safety. You receive the top MCA Live Transfer Leads will act as a business consultant for your organisation to increase sales.

    ReplyDelete
  4. Cell phones are not allowed on us planes after takeoff because we are told that it could interfere with plane instruments,
    personally thnk it was to hang on to in plane phone calls sales for which the airline makes a profit am also under the impression that the no cell phone policy is being reviewed at this time.

    ReplyDelete
  5. OH, okay! I always used to wonder why people are told to switch their phones to airplane mode when the flight is about to take off and finally this query of mine has also been resolved. I just bought the dissertation proposal help from an online site and I randomly clicked open this page that proved to be quite informative.

    ReplyDelete
  6. For the Federal Aviation Administration, safety is the highest concern. Portable electronic devices, including cell phones, iphones in karachi pakistan, emit radio signals that officials worry will interfere with aircraft communications or flight control, navigational and other on-board electronic equipment.

    ReplyDelete
  7. I'm not sure why airlines don't allow cell phones, but I imagine it has to do with preventing people from making calls during takeoff and landing. Maybe they're also concerned about people using their phones to take pictures or record videos during flights.

    ReplyDelete