Hex Code

Why is the API not returning the mode-s hex code? It literally is one of THE most important aspect of flight tracking. I’m sure that is also how FlightAware determines the registration of the aircraft.

Aircraft transponders also transmit a flight identifier (“ident”), which is a textual string that usually contains the operator and flight number, or otherwise a tail number. That is actually the most important aspect of identifying a tracked flight. Mode-S code is not always available (such as when the flight is not being tracked by ADS-B, like radar or datalink). We do however use the Mode-S code to populate the “registration” field when we can match it up in our lookup tables, if we haven’t received the registration through other flightplan information.

How do you identify an aircraft by the operator and flight number?

By, for example, matching to data sources that provide operator, flight number, and aircraft registration. ANSP data feeds often have this combination.

In some cases we don’t know the identity of the physical aircraft at all, but that doesn’t prevent us from tracking it!

Can you explain some more about your application – what’s the use that you’d make of the Mode S code that’s not covered by aircraft registration?

(We do provide Mode S address where available via Firehose, but at a glance I don’t see it in AeroAPI – perhaps that’s something that could be added in a later version of the API)

Yeah I understand, but every other flight tracker has the mode-s information. On a particular one you can even see all flights by mode-s only, which is really handy. Everybody knows you have that information for the majority of the flights in Europe, North America and many parts in Asia, especially since people literally feed you that information via ADS-B.

So having mode-s a.) available on the front end (like everybody else) or b.) having it the AeroAPI would be incredibly useful to help identifying aircraft.