Multilateration (MLAT) Data

Hello everyone. I’m posting today to update the community on how we provide MLAT results to our data feeder users and clarify how you can use this data. For our long-time participants, you may already be familiar with most of this. We want to make sure everyone knows about this free service we provide and how we make that available to you. As you may know, providing MLAT calculation results back to PiAware/FlightFeeder users enables you to track many more aircraft in range of your receiver than you would otherwise be able to do with only ADS-B data.

FlightAware is pleased to make multilateration (“MLAT”) aircraft position data (“MLAT results”) available to PiAware and FlightFeeder network participants at no cost. FlightAware invests significantly in the hardware, software and network resources to provide this service as a benefit to users that feed data to FlightAware. In exchange for your participation, FlightAware freely licenses the use of the MLAT results data to you for your personal and non-commercial use as long as you are a data feeder to FlightAware. You may use the MLAT results in several ways:

  • Via the Skyview web site running on your PiAware or FlightFeeder device in the web browser of your choice.

  • Via the JSON file output used by the Skyview web site. (For use by advanced users; this is not formally supported by FlightAware.)

  • Via direct network connection to TCP port 30105 or 30106 within your local area network. (For use by advanced users; this is not formally supported by FlightAware.)

FlightAware does not allow redistribution of MLAT results data to third parties via any means for commercial use or consumption by the general public with the exception that you may share the Skyview user interface with other users if you choose. Sharing of the MLAT results data for commercial use or public consumption in formats such as JSON, Beast, Basestation or any other format is not permitted. Furthermore, any aggregation of FlightAware MLAT results with other data sources is not allowed except for your personal, non-commercial purposes.

Additionally, to maintain the quality of our data feeds and MLAT results, feeding of any data other than Mode A/C/S or ADS-B to the FlightAware network is not permitted. For example, you may not feed MLAT results back to FlightAware as if it were native ADS-B data. Other data sources such as ACARS or any data from third party sources may not be fed to FlightAware’s ADS-B network.

This policy is to ensure the quality of our network and compatibility with our data processing infrastructure. Additionally, this policy enables us to continue to provide MLAT results as a free benefit to our network of over 13,000 sites and growing.

Thank you for your participation in the FlightAware ADS-B and MLAT network!


Can someone put the above in simple english on what can and cannot be done? Thx

The TL;DR is: do not distribute FlightAware MLAT results to third parties. In order to do this you would have to deliberately make custom modifications to your PiAware configuration so this is not something you are likely to do by accident.

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Thank You for providing the free data, which, as per my limited knowledge, gets generated by contribution from the same 13,000 sites you are talking about (more than half of which I presume are **free **PiAware). And I am (obviously) able to see only that MLAT data back at home which my own site contributed for.

Rightly said, significant infrastructure and effort is applied from your end to provide this free data to me, and you have all the right to control its distribution.

But please, don’t talk as if you are doing a favor to the 13,000 sites. You wouldn’t be generating so much of MLAT data with only your servers, without the PiAwares (who also, incidentally, put in a lot of effort, monetary and otherwise, to keep it all running).

P.S.: I don’t redistribute anything. I simply don’t appreciate the tone of your policy.


In my opinion there is no “tone”, it’s just normal legal contractual language. Clear and at the point. They have built the infrastructure on the backend, they provided the software and even hardware in some cases. We do this purely for hobby, if it is for anything else (commercial or not), then the above rule needed to be said.

PS: I wish that we, as a society, are not so easily “offended” by words. We truly became a snowflake society.


You wouldn’t have jack crap without FA’s servers and effort. Dump1090 was junk before FA and Oliver made it really work. MLAT to your Pi didn’t exist before. You’re right about your limited knowledge. Your comments and attitude are completely out of line. You joined only a year ago. I’m pretty sure this was already policy then, due to another web site taking the data and doing absolutely stupid things with it. But, yea, let’s talk about tone. Your tone.


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due to another web site taking the data and doing absolutely stupid things with it.

care to elaborate please ?

as for myself, I feel, I own and I control the data my system generates ( which then are being processed by FA - with my contribution) being the originator of the data.

Fortunately, I am not a lawyer but just a normal member of the human race and I am not trying to be rude nor pick a fight.

Having said that, I would have thought that the data originated in the aircraft and therefore the aircraft owner might be able to claim ownership of the data.

Much like the TV show that you receive I suspect that the creator is still the owner and we simply receive it, reformat it, and pass it on.

With all the carry-on about illegal down load and torrenting of TV shows and movies and copyright ownership we also may be at risk from copyright infringement.

I can’t believe I just wrote the above. :cry:

Have a great day and I am really pleased that MLAT has now been fixed and I can see it again on Skyview.


BTW, this benefit is precisely why I feed to FlightAware but not FlightRadar24.

Thank you for providing it.



the data originated in the aircraft and therefore the aircraft owner might be

no they can not because they do not provide a commercial product or service for sale !
they are obligated to ‘provide’ these data to ATC. the same data or part of it we intercept
and because are not freely re-broadcast having to go through my paid equipment and
software, the chain starts from me and I claim ownership. so I am not a ‘sheep’ contributor if you will.
The tracking sites provide the whole picture. For my hobby I do not really need them.
I can always stick to processing my own local data, display it, make graphs etc and if/when I need the
big picture I can internet it. Is because I am a nice guy that I contribute to the big picture !


What you do with data you receive locally on your own hardware is, of course, up to you!

The original post from Eric is about what you can do with the multilateration results which are generated using FlightAware’s hardware and software. FlightAware can only provide that data to you with some conditions attached. If you’re not willing to follow those conditions then unfortunately FlightAware can’t provide the data.

The original post from Eric is about

@ obj

yeah, I understand Eric has business to protect etc. I found some audacity in the OT… it drives the same way of FR24 to the same way of. of… of…
with proprieatary and $$$ increasing… now i don’t know how to or wish to exploit commercially the mlat data sent back by the server, but the way i see it is you exist - all of you flight tracking sites - because i feed you ! this is my point all along. but i am sure your lawyers have told you all about it, is a very weak case.

furthermore if you deny sending back mlat you must deny receiving my raw data too… and what that says about democracy !

I don’t really understand the complaint; isn’t mlat data with some conditions attached better than no mlat data at all?

You can opt out of mlat entirely (i.e. disable the sending of data to FA for mlat purposes) if that’s what you want - there is a setting on the stats page or you can “piaware-config allow-mlat no”.

There is no mlat problem, but there are cultural differences. 80 percent of the world’s lawyers live in the US and movies/documentaries like Rain man or Food Inc created a perception that the one with the most money is right.

I can’t deny that similar thoughts arose when I read the first post. I’m here for the fun of technology. I understand that these legal contractual rules are necessary in the US and possibly abroad; please understand that in other parts of the world such strict rules are not necessary and frowned upon.

If I slip due to a wet spot on the floor which wasn’t marked with a yellow sign, I would sue the owner of the store in the US. Over here we blame ourselves for not spotting it and are grateful that the owner gives us a ride to the hospital.


even harder - here in germany we import wet spots with the money from those who later slip :smiley:


I have used the two ports in VRS to rebroadcast FlightAware and my two other receivers on a composite map but recently changed to Fibr which didn’t allow interaction between the lan ports. To overcome I invested in a gigabyte switch between my server and the modem and a ddns provider to overcome a dynamic IP. Skyview works fine on the receivers local IP port 8080 on the FlightAware website. VRS will connect on ports local IP using either 30106 and 30105 and for that matter port 80 or 8080 but no aircraft are tracked. Since I have 2 other receivers they are tracking fine.

Has 30105 or 30106 been disabled with a FlightFeeder update?

That feature has not been disabled. You can contact us at for FlightFeeder assistance if you think something is wrong with the device.

Thanks Eric. I have determined the receiver is working properly it is just a bump in the road for VRS that doesn’t seem to like port 30105 but 30106 works as intended.

Thanks again!

John Cottingham
0995 3953100