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Thread: Air speed 0kts?

  1. #1
    Purser
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    Air speed 0kts?

    This morning, I am watching a line of arriving aircraft heading for Heathrow.
    First in the line is N768AA, followed by BA's G-BNLK, then Kuwait Airways 9K-AOB and finally AC C-FRAM.
    Of these 4 aircraft, the American Airlines and the Kuwait flight are showing 0kts air speed. The other 2 are showing sensible numbers.
    It isn't a radar related problem as the data is coming from the same radars.
    Coincidence that 2 of the 4 have a problem reporting air speed?

  2. #2
    Team FR24 Mike's Avatar
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    You don't write where you saw the problem. If it was within FAA coverage the data is not 100% reliable. I have not checked what aircraft type's they are but there are several B777-200 flying around showing incorrect transponder values.

  3. #3
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    I did indeed write where I saw them "arriving aircraft heading for Heathrow".
    They were all heading for the Biggin stack.
    The affected aircraft were indeed B777-200. The Air Canada was a B777-300. Well spotted!
    I wasn't moaning, by the way, merely curious.
    Re FAA data; I wonder when they are going to give up this 5 minute delay nonsense? I don't see how it can have a significant bearing on "security". A person with evil intent can figure out what is going on with a flight, even with an artificial delay. Pretty pointless, I would think.
    PS Since writing this, I can see another B777-200, N794AN, passing over the west of England, again heading for Heathrow, and showing 0kts.
    Last edited by Kelvin; 2013-11-01 at 08:49.

  4. #4
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    Curiouser and curiouser!
    I have had a look around and found other B777-200 around the world showing the same anomaly, 2 American Airlines, 1 Hanoi Airlines, 2 Transaero, 1 Orenair and 1 China Southern.
    All other airlines flying the same model appear to be fine.
    Oddly, AA flight AAL38, N751AN, is showing the correct data.

  5. #5
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    Quote Originally Posted by Kelvin View Post
    Curiouser and curiouser!
    I have had a look around and found other B777-200 around the world showing the same anomaly, 2 American Airlines, 1 Hanoi Airlines, 2 Transaero, 1 Orenair and 1 China Southern.
    All other airlines flying the same model appear to be fine.
    Oddly, AA flight AAL38, N751AN, is showing the correct data.
    I wonder if this might be related to aircraft age or if they have an inertial navigation system feeding the ADS-B transmitter.

  6. #6
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    N794AN B777 was put in service on 11/21/2000. I believe it may have the inertial system due to it's age.
    F-KTMB1

  7. #7
    Captain fungus's Avatar
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    Quote Originally Posted by Kelvin View Post
    This morning, I am watching a line of arriving aircraft heading for Heathrow.
    First in the line is N768AA, followed by BA's G-BNLK, then Kuwait Airways 9K-AOB and finally AC C-FRAM.
    Of these 4 aircraft, the American Airlines and the Kuwait flight are showing 0kts air speed. The other 2 are showing sensible numbers.
    It isn't a radar related problem as the data is coming from the same radars.
    Coincidence that 2 of the 4 have a problem reporting air speed?
    This is quite a common problem throughout the world which (as you rightly pointed out) has nothing whatsoever to do with either the radar receivers or with FR24. When they add ADS-B to an aircraft (even if it is installed at the production phase) it isnt just a matter of whacking in an ADS-B Transponder and off you go. The airspeed is fed from the airspeed indicator and the heading from the heading indicator and it's quite common, as it is not yet a legal requirement for fitment or use of the technology (yet) in most parts of the world that these instruments (that show airspeed/heading etc and sometimes even the rate of climb/descent) are not yet connected so dont show on the FR24 map. Some aircraft (and SOME LAN Chile A340's which I see regularly here in SYD is one that immediately comes to mind ) have those aircraft still emitting false data on their longitude position which splays them all over the world on our receivers but fortunately FR24 have been able to (in most cases) eradicate this issue with updated uploader technology.

    In time this equipment will be operational, as it becomes mandatory and hence observable on ALL aircraft equipped with and using ADS-B transponders. In the meantime FR24 (due to the information that we upload which is received directly from the aircraft) will display whatever is being transmitted.

    Regards,
    Gregg
    Last edited by fungus; 2013-12-03 at 21:12.

  8. #8
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    Quote Originally Posted by ko4e View Post
    N794AN B777 was put in service on 11/21/2000. I believe it may have the inertial system due to it's age.
    I doubt that any B777 would have been manufactured with inertial navigation for no other reason than until the B787 came along the 777 was Boeing's technology leader. More likely, as Fungus suggests, a poor interface between other instruments and the ADS-B equipment. AFAIK only Europe and Australia currently have regulations that even approach making ADS-B mandatory for air navigation purposes and I've not observed issues with any B777s that fly into Australia and there are heaps of them from at least a dozen airlines.

  9. #9
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    If that is the case, I wonder if more countries will force the equipment to be fixed ... by preventing the aircraft from entering the airspace if it doesn't work ( like the LOT dreamliner that wasnt allowed into Norwegian airspace), or alternatively not allowed to take off once landed ... or stay under 18000 feet.

    Sent from my GT-P5110 using Tapatalk

  10. #10
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    Quote Originally Posted by airnrail View Post
    I doubt that any B777 would have been manufactured with inertial navigation for no other reason than until the B787 came along the 777 was Boeing's technology leader. More likely, as Fungus suggests, a poor interface between other instruments and the ADS-B equipment. AFAIK only Europe and Australia currently have regulations that even approach making ADS-B mandatory for air navigation purposes and I've not observed issues with any B777s that fly into Australia and there are heaps of them from at least a dozen airlines.
    Asiana has been an 'offender' in that regard with their 777's into SYD for some years now but I see they are now being sorted out. (I use the term 'offender' quite loosely here as it's not an offence as such yet in the legal sense). As Mike pointed out, so have others.
    Regards,
    Gregg
    Last edited by fungus; 2013-12-04 at 03:37.

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