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HEX Allocation and the looming 2020 Mandates

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  • HEX Allocation and the looming 2020 Mandates

    Figured have a chat here rather than polluting the Dbase section..

    Does it come of a concern to anyone else how close we are to the mandates around the planet to requirement to have full WORKING ADSB transponders we are, yet the operators and owners - who are at the hands of the safety of themselves and others don't seem to be grasping the importance of the requirements?

    I know the 'rest of the world' doesn't usually concern themselves/recognise the FAA. But they do tend to have their own administration with the role of Aircraft management. Or presumably arranging intercontinental movements/flightplans wouldn't happen?..

    I wouldn't have expected a group of hobbiests at home who don't themselves fly (the majority that is), to seemingly be at the forefront to be the ones able to spot and advise operators (there appears to have been a recent increase in owner/operators installing/taking over newer ADSB units?) that the configuration they're attempting to continue with jepordises the mandates.

    I've seen numerous FAA run case studies around inconsistencies with South America (and others) and the difficulty with aligning a proper registrar management and allocation. Surprisingly, it appears to be only Mexico that has an impending deadline

    They seem to be able to control those who actively request checks for errors and advise to remedy, but it seems unless you are TXing your true tailnumber for the flight for ATC to advise or contact each operators register to advise the owner there doesn't seem to be a way to track back who the wrong ones are and get them changed.

    Bit of a worry when we've been able to on a public forum huh?
    Posts not to be taken as official support representation - Just a helpful uploader who tinkers

  • #2

    The State of Registry or common mark registering authority will assign exclusive
    aircraft addresses within each block to aircraft when required for use by duly
    equipped aircraft listed in a national or international registry.
    b) Aircraft addresses will be assigned in keeping with the following principles:
    at no time shall the same address be assigned to more than one aircraft;
    • a single address shall be assigned to each aircraft regardless of the
    composition of its airborne equipment;
    • no address shall be modified except in special circumstances nor will they be
    modified during flight;
    when an aircraft changes its State of Registry, the previously assigned
    address shall be relinquished and the new registering authority shall assign it
    a new address;

    NACC/DCA/3 - WP/05
    - 4 -
    • the address shall be used exclusively for the technical function of aircraft
    addressing and identification and not for transmitting any specific
    information; and
    • no address consisting of 24 zeros or 24 ones shall be assigned to aircraft.
    3.6 It should be noted that there are occasions when aircraft show an incorrect 24-bit address
    due to its installation or internal lay within the aircraft itself. This can occur not only during the first
    installation of a Mode S transponder, but also when a major modification is made to the Mode S
    equipment, followed by a change in registry. Incorrect installation, such as the setting of the address to all
    zeros or an inadvertent duplication of an address can represent a flight safety risk. The ACAS II system,
    in particular, operates on the assumption that each aircraft has a single unique 24-bit address. An incorrect
    or duplicated aircraft address can seriously degrade ACAS II performance
    and in some cases even disable
    as well as degrade the efficiency of Mode S radar-based surveillance services.
    Posts not to be taken as official support representation - Just a helpful uploader who tinkers


    • #3
      Also the amount of aircraft that don't have Mode-S transponders......still using Mode A/C.....

      There are too many miscodes to correct and there is no process to correct them (its hard enough here ) I have worked with aviation authorities on this subject and nobody can agree how to, there basically isn't a workable solution. Some national authorities are not interested either.

      Its very unlikely that a radar station will see two aircraft with the same hex, if it does the callsign (will be different) and squawk (is most probably different), so the controller will know which aircraft is which.

      I have a single hex code in use in Italy that's being used by 21 different aircraft.