1. OCAU Merchandise now available! Check out our 20th Anniversary Mugs, Classic Logo Shirts and much more! Discussion here.
    Dismiss Notice

GPS on a plane

Discussion in 'Electronics & Electrics' started by invisable, Oct 28, 2006.

  1. OP
    OP
    invisable

    invisable Member

    Joined:
    Sep 6, 2003
    Messages:
    220
    Location:
    Noosaville, QLD


    why is it that wireless and bluetooth are allowed but a non transmitting device is banned, what about a FM transmitter(not that you have anything to transmit to),

    me thinks these rules were made by some lawyer that is computer illiterate and have no idea about how the plane works

    lawyer - "well planes don't use wireless or bluetooth so they should be fine, but because they use gps, banned"

    i would say that all wiring on a plane would be shielded to prevent this
     
  2. nux

    nux Member

    Joined:
    Jan 20, 2002
    Messages:
    16,780
    Location:
    Melbourne
    Yes, I thought that was my point.

    No, SHOULD be shielded. Some planes flying may be 20 years or more old, how were the designers to know what technology may be used in the plane in 20 years? How can we know now?

    Many accidents have been caused by a series of chances whose probability of all happening in the right order are obscenely small. But they still happen, and people die.


    What I am saying is, I would prefer all electronics to be banned, rather than allow almost anything. Bluetooth and 802.11x should be banned over GPS of course.
     
  3. mAJORD

    mAJORD Member

    Joined:
    Jun 4, 2002
    Messages:
    10,704
    Location:
    Griffin , Brisbane
    It's been proven that even mobile phones have little effect on nav gear, even when placed right on top of it, but like nuxie said, why take the risk. Afterall such tests are in controlled conditions.

    There have been plenty of cases in the past of mystery happenings, that some think may have been caused by interference from some device. such as a phone.

    There is no room whatsoever for risks in aviation, and The only way you could get rid of the risk is to check every persons device that they want to turn on and ensure it complies to regulations for emmisions. Are you going to line up and do that?

    I don't think so, so just turn everything off and there is no risk. Hostie's aren't to be expected to judge whats potentially off limits and what's not.
     
  4. nux

    nux Member

    Joined:
    Jan 20, 2002
    Messages:
    16,780
    Location:
    Melbourne
    But even still, I believe commercial navigation equipment works on 800MHz or 850MHz which is in the same range that a lot of mobile phones work on. Plus you get the EMI, which you can see from a mobile phone when a call comes through and your CRT screen shakes or speakers get interference.

    I agree with you completely, you may be able to test a certain type of device and find that its fine in a controlled lab environment. But in the real world a lot more goes on, and different devices behave differently together etc etc.
     
  5. Xxian.com

    Xxian.com Member

    Joined:
    Mar 16, 2006
    Messages:
    115
    I'm just thinking about all the mobile phone towers in the suburbs surrounding airports, blasting out lots of 800MHz band, right where an aircrafts instruments are most critical, take off and landing.

    I'm pretty sure from memory, the building that used to be Travelodge at Tullamarine has a mobile network array on its roof - across the road from the airport.

    Plus considering the amount of RF that a plane must pass through in its course of travel anyway, I wouldn't have thought the little bit of emi a gps would cause would be of any great concern.

    Has anyone flown in a small plane? Generally they have a built in gps, but the pliot also has his own hand held version he sits on the 'dashboard' - in every light aircraft I've flown in - whats the difference? Theirs better than mine?

    And I would have thought a computer or hand held game ie PSP would cause the same amount of emi or more even, than a gps.

    The scanner, well, I can relate to, as being a CBer from way back, having the scanner sitting beside the radio, the scanner would actually cause interference to the cb if it stopped on a certain multiple of the frequency the CB was sitting on - so yeah, even though it doesnt transmit, it does cause interference in certain situations.
     
  6. nux

    nux Member

    Joined:
    Jan 20, 2002
    Messages:
    16,780
    Location:
    Melbourne
    Yes they do. However the base towers have very strict bands to emit on. Mobile phones are not due to their incredibly low power output. Also consider that most of a planes equipment is basically inside a giant faraday cage (the aluminium shell), and so any radiating source inside the plane will just bang around inside the plane, effectively amplifying it.

    No they are just a standard GPS. However light planes are much less sophisticated, with far far fewer systems that must work together to keep the airplane flying. Also, light planes fall out of the sky much much more often than commercial jets. However when a commercial jet does, the casualties are much much higher.

    No one said they don't. As I said, 99.99999% of GPS's probably wouldn't cause any effect when used on an airplane. Same with all the other allowable devices. However airlines are driven by the bottom line, people want to use PSP's and laptops, so they allow them even though they do probably pose a much higher risk to your safety than a GPS. No one is disputing that.
     
  7. nudge

    nudge Member

    Joined:
    Sep 5, 2001
    Messages:
    860
    Location:
    Amsterdam NL
    Worth a read:

    IEEE Spectrum Magazine (March 2006)
    Unsafe At Any Airspeed?
    By Bill Strauss, M. Granger Morgan, Jay Apt, and Daniel D. Stancil
    Cellphones and other electronics are more of a risk than you think

    http://www.spectrum.ieee.org/mar06/3069
     
  8. JaC

    JaC Member

    Joined:
    Jun 27, 2001
    Messages:
    1,041
    Location:
    Brisbane

    Not quite. Aircraft qualified GPS receivers need to be tested and found to be in accordance with certain standards (TSOC129/TSOC145/146). Certain algorithms must be used and integrity monitoring is critical in airborne applications.

    Also, FYI, RNAV is all around 110MHz.
    VOR is ~108-112MHz, and DME is 113Mhz (exact figures off the top of my head, probably slightly out)

    All the important stuff (ie everything) in aircraft will be shielded, even in older aircraft. Full rewires are a part of scheduled maintenance.

    A lot of aircraft will also have a CDMA phone as part of the comms system.
     
  9. nux

    nux Member

    Joined:
    Jan 20, 2002
    Messages:
    16,780
    Location:
    Melbourne
    I can understand that would be so for inbuilt GPS's, but a number of pilots I know and have travelled with use 'off-the-shelf' handheld GPS's as well. One uses his boat GPS so he can go over his fishing waypoints to see if there is any pelagic activity :p
     
  10. busky2k

    busky2k Member

    Joined:
    Aug 23, 2001
    Messages:
    963
    Location:
    Adelaide, SA
    I tried my GPS PDA in a plane and it wouldn't pick up any satillites. I can't see why it should be illegal though.. its doesnt transmit any signal whatsoever unlike phones etc.
     
  11. picollo

    picollo Member

    Joined:
    Aug 9, 2001
    Messages:
    200
    Location:
    Brisbane Northside
    i took a gps on a virgin flight last year. just interested how fast we were going and where we were over. always wonder what im passing. the hostie chick asked me what it was and told me if i could turn it off about 30 mins into the flight. no probs. going at 800ks. pretty interesting.
     
  12. Iceman

    Iceman Member

    Joined:
    Jun 27, 2001
    Messages:
    6,647
    Location:
    Brisbane (nth), Australia
    Wait, it says radio transmission. They might be talking about GPS tracking devices. ie the type that read the signal (passive) then transmit what it reads either via radio or back to a sat (active).

    In any case, in todays age of paranoia through ignorance, I would write to someone at the airline stating very clearly and simply the brand/model/purpose of any such device you would want to use and ask them to confirm it's ok to use. Take the letter with you.
     
  13. Jaws_au

    Jaws_au Member

    Joined:
    Dec 28, 2001
    Messages:
    1,932
    Location:
    Brisbane
    It's too early in the morning here to go into details, but any kind of reciever has SOME kind of leakage at the IF... how do you think the police can detect radar detectors??

    Hence why GPS and radio scanners would be illegal for use on a plane, because they are both operating at the exact same IF as actual systems.

    So whilst the risk is still very low of causing actual noticable interference with a GPS, it is still more likely than causing problems with say your MP3 player.
     
  14. Jezmad

    Jezmad Member

    Joined:
    Sep 6, 2004
    Messages:
    1,283
    Location:
    WA
    IIRC Wifi and bluetooth are banned on Qantas.

    Read the text, it says wifi and bluetooth "enabled" devices can be used. That cabin announcment mentions the must be in flight mode.
     
  15. LethalCorpse

    LethalCorpse Member

    Joined:
    Mar 23, 2003
    Messages:
    3,760
    Location:
    Cambridge, Massachusetts
  16. mAJORD

    mAJORD Member

    Joined:
    Jun 4, 2002
    Messages:
    10,704
    Location:
    Griffin , Brisbane
    haha, about time :Pirate:
     
  17. 2xCPU

    2xCPU Member

    Joined:
    Jan 21, 2005
    Messages:
    3,328
    Location:
    Saigon
    Wow, there is so much BS in this thread - how about some facts / quotes (apologies to those that have).

    The word from Boeing

    http://gpsinformation.net/airgps/boeingsvcltr.pdf


    A list of airlines that do / don't allow the use of GPS (receivers)
    http://gpsinformation.net/airgps/airgps.htm

    The fastest I've recorded is 915km/h - so, yes it does work
     
  18. OP
    OP
    invisable

    invisable Member

    Joined:
    Sep 6, 2003
    Messages:
    220
    Location:
    Noosaville, QLD

    i have never heard that on the many flights i have been on,

    and why does it say that a gps is banned but wifi and bluetooth enabled devices can be used, wouldn't you think if is was banned they would just say it?



    hey i didn't know that they made a sequel already, and i whought it was going to be called sharks on a train
     
  19. Xxian.com

    Xxian.com Member

    Joined:
    Mar 16, 2006
    Messages:
    115
    So QANTAS is relaxing its laws on mobiles, allowing them to be used in flight now, maybe other electronic devices such as GPS' and scanners will be reviewed soon also?
     
  20. 2xCPU

    2xCPU Member

    Joined:
    Jan 21, 2005
    Messages:
    3,328
    Location:
    Saigon
    Are you saying Qantas specicialy don't allow scanner and GPS?

    Qantas are on the list above that do allow GPS and the answer in their FAQ read like this:

    Link
     

Share This Page

Advertisement: