Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Why phone to switch off in flight mode?

  1. Dec 8, 2015 #1
    In flights during landoff or takeoff they say to keep the phone in flight mode and then switch off so as to not interfere with the aircraft signals.
    But why should we switch off if keeping the phone in flight mode?
    Flight mode disables cellular and wifi networks.
  2. jcsd
  3. Dec 8, 2015 #2


    User Avatar
    Gold Member

    Now in the US and EU they don't request you to turn it off, only to switch to flight mode. Maybe this hasn't changed yet in other parts of the world.
  4. Dec 8, 2015 #3
    In some places the rule is just all electronics, period, because the regulatory environment in those places is still catching up to new interference and communications standards in wireless technology.

    I think the concern is that any interference, no matter how weak, runs a chance of interfering with an important signal, when the cost of failure should an important signal be corrupted is a billion dollar airplane and the lives of its 200-some passengers, asking you to have your electronics off for 5 minutes doesn't seem like that much of a tall order. Post -9/11, at least in the US, the concern was also that electronic jammers could be disguised as innocuous, non-networking devices like GameBoys or MP3 players, though this worry turned out to be unfounded.
  5. Dec 8, 2015 #4


    User Avatar
    Gold Member

    [QUOTE="jack476, post: 5313552, member: 484239"
    I think the concern is that any interference, no matter how weak, runs a chance of interfering with an important signal,[/QUOTE]
    I think it has much more to do with the uncontrolled element in monitoring a large group of people.

    Who knows that every device is switched to satellite mode? And never mind cellphones - who knows what devices are out there at any given time? They can't be checking that cellphones are OK but quadcopter control panels are not OK.

    The blanket 'turn off all electronic devices that are capable of broadcasting a signal' is the safest - and most expedient for cabin crew - option. They sure don't need every boarding operation to dissolve in an aisle-side argument with a passenger about the capabilities of a device they aren't familiar with.
  6. Dec 9, 2015 #5
    And what if a person doesn't switch off and also doesn't keep in flight mode. The attendants cannot get to know. Maybe there are few people in flight who do not follow this rule. Does this have a harm and if not then why are attendants are imposing this rule of switching off?
  7. Dec 9, 2015 #6

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2017 Award

    A wrong action does not become right merely by having a low probability of being found out.
  8. Dec 9, 2015 #7
    But plane might be having protected system as attendant can't check every passenger's mobile phone?
  9. Dec 9, 2015 #8


    User Avatar
    Gold Member

    It's a cost-risk-benefit thing.

    They can't check everyone. They can't install a system that checks.
    They can take best precautions that don't unduly disrupt the flight.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook