ICAO mode-s transponder code allocation
 

hi there,

This might not be the correct forum for this question.

I'm looking for an up-to-date source of the ICAO mode-s transponder code allocation document. Anyone knows who actually manages the list of ICAO 24-bit adresses which contains the adress ranges assigned to each country?

thanks

Blackswan,

I was not able to find anything on the official ICAO web-site, but that was after just 10 minutes of looking. I did find references elsewhere to "ICAO ANNEX 10 Volume III Chapter 9" which gives the list you want.

Searching for that term I came across http://www.peter2000.co.uk/aviation/...Volume_III.pdf which does contain a list (not necessarily in the format you want, but ...), and I have no idea how up-to-date it is. That said, I'm not aware of any/many changes (to the allocations of ranges of codes to countries) that have happened in the past 5 years. That information is also available from KLOTH.NET - ICAO 24 bit aircraft ID .

hey,

Thanks, I guess I have to find the latest copy of ICAO ANNEX 10 to make sure. There are just a few codes I'm struggling to assign to a register. e.g. 22DD82 (1000101101110110000010)

regards

Blackswan,

you have to remember that not every 6-digit hex-code is used; there are vast ranges that are not allocated to any specific country (for future use?), and for those ranges that _are_ allocated there may be similar large quantities that are not used yet.

Your 22DD82 is one of the former, in a range not allocated to a country. It is almost certainly a bad decode (of which there are plenty), or incorrect data entered into the avionics (of which there are plenty).