What you’re trying to access is global legacy ICAO system called the Aeronautical Fixed Telecommunications Network (AFTN). Flight plans were one of a few core uses that the AFTN was originally built to accommodate. If you are interested in looking at the history of the system, elements of which are still being used in many underdeveloped countries around the world, you’ll find that it was basically a global email network before email was even called electronic mail!
If you are a business aircraft pilot in South Africa, and file a flight plan all the way to Turkey, the AFTN is the mechanism used to forward the flight plan details to every ANSP in every FIR the flight will cross. There every ICAO member state assigns there required civil aviation and ATC facilities with a unique AFTN Address, so discreet messages and information can be send directly to them. Sound familiar?
That said, when first stood up (1940’s or 50’s) the entirety of the AFTN was originally built using long stretches of copper cable, which eventually could reach any address on the planet. If was, and still is where it’s still used, a very analog based system. As the digital revolution spread around the world, the better funded, more developed nation’s decided to up their AFTN game by going digital. The digital follow on to AFTN is called the Air Traffic Services (ATS) Message Handling System (AMHS). Leave it to aviation to create multi level acronyms.
There AMHS provided the same functions as the legacy AFTN, only using digital protocols which didn’t require dedicated copper cables, instead relying on the now global shared network connectivity infrastructure. In order to accommodate those nations unable or unwilling to upgrade to AMHS, the system was designed with multiple analog to digital converter bridges. These allowed the less resourced nations to upgrade even they could. Unlike other technology innovations like ADS-B which offer a significantly low initial investment cost and continued savings moving forward, converting to AMHS wasn’t as appealing.
However, AFTN’s days are numbered. ICAO has mandated that app member nations transition to an IP based equivalent (you know, line AMHS). They may have already begun the phase out in earnest, but I’m no longer plugged into that crowd anymore.
Lastly, all this is great, but doesn’t help you unless we circle back to your core question: How do you get your hands on some of that delicious AMHS flight plan data? The answer won’t be encouraging, but I’m not saying it’s impossible. The first challenge is to do the research to determine what FAA network program the AMHS currently falls under. They seem to rename these things annually, but start with the SWIM program. That was the last program management moniker for sharing any data related to civil aviation with the private sector/ interested citizens. You’ll likely be told that you haven’t demonstrated a need for access to this data, but don’t fret. The FAA is a huge, complex, bloated beast which can be approached in a hundred different ways.
In the mean time, if you Google either AFTN or AMHS, you’ll be drowning in information. As far as FlightAware’s origin for flight plan data, at least as of a couple years ago was based on the correlation with the historic call sign/ flight number flown routes, and not AFTN/AMHS, but that may have changed. That said, the lack of corporate or GA flight plans associated with non-air carrier airports suggests this is still the case.
That’s a lot, but I saw an opportunity to assist. I hope it did.