7
$\begingroup$

The description of PlanePlotter claims that it can determine the registration letters from the ICAO 24 bit address algorithmically for some countries.

The only thing i got so far is how to get the country. Any clues?

Edit:

After some more research I found some information in the book "Principles of Avionics" by Albert Helfrick:

Generally, there is no algorithm giving a one-to-one correspondence between ICAO 24 bit addresses and the registration number of the aircraft. Some ICAO member states did have an algorithm that would translate ICAO 24 bit aircraft addresses to registration numbers but ICAO strongly suggested the practice to stop.

Algorithm for swedish registrations: http://www.transportstyrelsen.se/publicdocuments/PDF165.pdf

$\endgroup$
  • $\begingroup$ Maybe some countries have a system and the people at PlanePlotter reverse engineered them? $\endgroup$ – ratchet freak Oct 31 '14 at 23:48
  • $\begingroup$ Do you have a link to this claim? $\endgroup$ – usernumber Oct 31 '14 at 23:50
  • $\begingroup$ coaa.co.uk/planeplotter.htm "PlanePlotter can can determine the registration letters algorithmically, from the 24-bit hex address" $\endgroup$ – Chris Oct 31 '14 at 23:56
  • $\begingroup$ Is there anyway to tell if the aircraft is rotary or fixed wing from the ICAO 24-bit address? $\endgroup$ – wittrup Sep 11 '15 at 0:03
3
$\begingroup$

Apparently (according to these folks) some countries use an algorithm to generate their ICAO (Mode S) 24-bit IDs. For those countries, you can simply reverse the algorithm and get a registration given the Mode S ID.

Others countries allow you to download their registration database, complete with the Mode S identifier (you can get the US registration database here) - it's a simple matter to load this into your own software and map the ICAO/Mode S ID code to a registration number.

As the folks at Gatwick Aviation Society have noted, some countries are tight-lipped about how their codes are assigned (and who they're assigned to), so these lookups are probably not complete.

$\endgroup$
1
$\begingroup$

The Mode_S closed-group on Yahoo Groups has documented many of the allocation algorithms.

https://groups.yahoo.com/neo/groups/Mode_S/info

Apply to join and explain your motivations. They have an extensive Files section.

$\endgroup$
  • $\begingroup$ There are no algorithms documented in the Files section of that group that I can find, only lists of <ICAO>,<algorithmically generated registration #> $\endgroup$ – John Wiseman Apr 25 '16 at 15:04
  • $\begingroup$ Not only are there no algorithms in that Files listing, but the listing for Belgium is very incomplete and contains lots of tail codes that are not even allowed - all the ones starting with Q for example. $\endgroup$ – Petoetje59 May 6 '16 at 13:03
1
$\begingroup$

From publicly available FAA tie-up data I figured out what the algorithms are that relate the American N numbers to their ICAO hex address - there are 24 algorithms in all for the 12 categories of 915399 possible N numbers. I turned these into a little Windows commandline application which works two-ways, N number <--> ICAO address. If somebody is interested, just ask for it : hero@ccstrombeek.be. The derived algorithms are available too (in Dutch only).

$\endgroup$
0
$\begingroup$

Some countries use a deterministic formula (e.g. US, Japan, South Korea), others use do not. There are about a dozen or two that do have a formula. Take a look at the popular ADS-B decoder dump1090's decoding logic.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.