According to this guy, the plane never turned off its transponder:
Yep, this caught my eye too when the story first went viral, since I know a little bit about how ADS-B etc. work. Seems people online just got confused about all this.
Basically, flight control stations use
radar to track aircraft, which has nothing to do with transponders. Then, there's the transponder (ADS-B) which is a secondary system making things easier - anybody can receive those signals with a simple scanner or even a Raspberry Pi. This is how things like FlightRadar work: volunteers all over the world set up receivers for ADS-B and feed what they get into the system, which then gets aggregated and plotted on a map etc. These days this may even be done officially by bodies like the FAA (they have an official data feed).
Now, I just looked up LADD: due to privacy concerns, the FAA established a program called LADD (Limiting Aircraft Data Displayed), which enables aircraft operators to request to block identifiable info from the FAA data feeds.
It's important to understand that this doesn't stop the transponder, and the data remains accessible to the flight controllers - it just filters public dissemination. However, anybody with a scanner/radio receiver could still receive the signals and fully decode them (they are not encrypted at all).
Needless to say, if you are the MOSSAD or whatever, here's how you would
NOT go about hiding your shenanigans: sending an email to the FAA to request your flight data be filtered when it goes out to FlightRadar, while it still gets sent via radio, is still read by flight controllers, and remains available in all kinds of databases :)
EDIT: I was wondering about how they prevent the volunteer networks from pumping out the data, and
there's another initiative for that:
LADD only addresses the use of data through FAA data systems. Non-FAA, third-party data sources are able to capture ICAO aircraft addresses directly from ADS-B Out transmissions.
To address the privacy concerns with access to this data, the FAA has created the Privacy ICAO Address (PIA) program, which allows operators to use alternate, temporary ICAO aircraft addresses that aren’t tied to an operator in the Civil Aviation Registry (CAR). For the maximum level of privacy, operators should participate in both the LADD and PIA programs.
Would be interesting to see if the data from the plane in question still shows up on the volunteer network (as opposed to the official FAA feed).
en.wikipedia.org
