Privacy Lost In The Age Of ADS-B

Replace the word "car" with "airplane," and you don't have to imagine anymore; that world is here today. Many of us grew up reading classic books like George Orwell's 1984, which illustrated a potential future world in which the government could peer into our personal lives, and privacy was no more. We understand that, to some degree, "Big Brother is Watching" and ADS-B data can be used by the FAA to track airspace incursions and other violations of the FARs. What we may not have been prepared for is that everyone else is watching as well, and more closely than you might imagine.

Automatic Dependent Surveillance and Broadcast (ADS-B) technology has arrived, and it offers some significant improvements in collision and weather avoidance, safety and air traffic control. However, the technology infrastructure that makes ADS-B possible is an open system that allows anyone with an ADS-B receiver to gather tracking information from aircraft flying overhead. In addition, the FAA publishes a feed of all flight data, including flight plans, that any company or individual can subscribe to. When these two sources of flight activity are coupled to the public pilot and aircraft registry, virtually all information about your flying can be made open to the public!unless you take measures to protect your privacy.

The FAA and NTSB recognize these issues and recently introduced a series of programs to attempt to protect the privacy of flight information. However, they're somewhat limited in what they can do because some of the core issues are beyond their control.

For example, the United States is one of the only countries in the world that makes pilot and aircraft registration data publicly available. Even some of the top FAA officials I've spoken to find this practice objectionable. However, changing the regulations that govern data privacy requires legislative buy-in. For that to happen, the industry groups who represent pilots and aircraft owners need to lobby for changes---changes that the FAA seems ready, indeed, even eager, to comply with.

Protecting your privacy requires an understanding about where your flight data goes and how it leaves the security of the FAA and ATC. The best way to understand this is to break it down into two parts: data coming out of the FAA/ATC vs. data coming out of your aircraft.

The FAA has a data feed, known as the System Wide Information Management (SWIM) network. SWIM is the digital data delivery platform that turns raw National Airspace System (NAS) data into meaningful information for aviation stakeholders. Registered consumers have access to more than 100 information products, including flight plans filed and flight information for actively tracked flights by ATC. Everything you file on your flight plan is sent out on the SWIM network, along with everything that ATC receives from your aircraft while you are within range of ATC tracking systems and/or while using ATC services.

Anyone can subscribe to the SWIM network and begin using this flight data---any company or any individual. All it takes is filling out a short application and agreeing to some basic rules on how you publish the data. Well-known companies such as FlightAware and Flightradar24 are subscribers to the SWIM network, along with hundreds of other companies, airlines, schools, individuals and the Department of Defense.

If you're flying on a flight plan, chances are that a lot of people out there know how many people you reported are on board, your fuel at departure, pilot, remarks and other things that you might assume were only being used by the FAA.

As noted earlier, the FAA isn't the only source for flight data. The ADS-B transmitter on your aircraft is continuously transmitting information about your aircraft, position, speed, etc. This includes three important pieces of information about your aircraft:

Aircraft ICAO Identifier (a hex number that translates to your N-Number on the FAA Registry)

N-Number (used by most U.S. GA pilots)

or !Flight ID (used by businesses, airlines and some individuals)

Since ADS-B is an open technology, anyone with an ADS-B receiver can listen in on the transmissions from aircraft flying overhead, gather the flight data, and share it with others.

And share it they do. The FAA controls access to data from the SWIM network, and companies have been concerned from the beginning about losing access to this data if the privacy rules were to change. This, in addition to the quest to fill in any gaps in ADS-B coverage, has led to the emergence of a massive, worldwide private ADS-B receiver network. Companies like Flightradar24 have programs offering people free ADS-B receivers to help enhance their networks, and organizations such as ADS-B Exchange help people build or acquire inexpensive receivers to contribute to their network---a network that is completely independent from the SWIM network.

Depending on the ADS-B system you've installed and the type of flying you do, there are a variety of options to help you protect your privacy:

1. UAT Anonymous Mode

There are two types of ADS-B systems when it comes to the data they transmit "OUT," and they are identified by the frequency that they use: 1090 and 978 (UAT). 1090 is the worldwide standard and has no limitations on altitude or where it can be used. UAT, on the other hand, is limited to flights within the U.S. and below 18,000 feet. However, UAT systems have one significant advantage when it comes to privacy: Anonymous Mode. UAT systems can be installed with a switch to turn on Anonymous Mode when the aircraft is squawking 1200 on a transponder and not using ATC services. Once enabled, the ADS-B sends out "VFR" in place of the N-Number in the transmission data. However, this only works when you are squawking 1200 and your ICAO is still in the data feed, so it has limited value for protecting your overall privacy.

2. FAA Limiting Aircraft Data Displayed (LADD) Program

To help protect pilots, the FAA recently launched the LADD program. This is an evolution of the previous Block Aircraft Registry Request (BARR) program that limits participating aircraft data in the SWIM network. Within the LADD program, aircraft owners have two options to protect their data: Source-Level Blocking and Subscriber-Level Blocking.

You can enroll in LADD for free on the FAA's website. If you choose Source-Level Blocking, your aircraft's data will be scrubbed from the FAA SWIM data feed entirely. Participating websites such as FlightAware or Flightradar24 will never receive your data (at least not from the FAA). If you choose Subscriber-Level Blocking, your aircraft flight data will be sent to all subscribers, but they will be restricted from displaying it publicly. Essentially, all SWIM participants are required to reference the LADD database and remove those aircraft from public display. Subscriber-Level Blocking still allows those companies to provide tracking services to the owners of the aircraft, but they usually charge a fee for this tracking as a premium service.

Unfortunately, the LADD program only protects the data that comes from the FAA through the SWIM network. It doesn't keep your flight data from being shared by all of the private ADS-B receivers around the country.

3. Flight IDs

Another option available to pilots is the use of Flight IDs, instead of using your N-Number. For between $250-$300/year, companies such as FltPlan.com and ForeFlight have services that allow you to use their company's Flight IDs for your aircraft. If you use this service, you would get a flight ID before each flight through their websites, program it into your ADS-B system, and use it over the radio when flying. For example, FltPlan.com customers are issued identifiers that begin with "DCM," followed by a four-digit number. On the radio, they use the name "DOTCOM," as in "Boston approach, DOTCOM 4425 is an A36 Bonanza, VFR 5 miles north of 6B6 Minuteman Airport at four thousand feet, requesting flight following to Albany."

Again, the weakness in the system is that your ADS-B transmitter is still sending out your aircraft's ICAO code, which translates to who you are on the FAA public registry. So, while you will be anonymous on the radio and to some flight tracking websites, most will still be able to see your actual aircraft registration number.

4. FAA Private ICAO Address (PIA) Program

PIA is another program offered by the FAA that provides the highest level of privacy currently available. Essentially, the PIA program allows aircraft owners to get a special, non-published ICAO address, which is linked to their aircraft. Think of it as a "Virtual Tail number" for your aircraft that you program into your ADS-B unit. It does not replace your aircraft's tail number; it's an unpublished address that the FAA links to the N-Number painted on your aircraft (and associated ICAO number) in its private PIA database. You can still use your public ICAO/N-Number anytime you want, as long as you re-configure your ADS-B unit to send out the public number. In fact, you'll need to do that anytime that you leave U.S. airspace because private ICAO addresses may only be used in the U.S.

One catch of the PIA program is that it requires you to use a Flight ID in order to participate. In theory, since every ICAO address has an N-number equivalent, you could easily use the PIA N-Number and not need a Flight ID at all. But the FAA decided not to allow that, citing confusion that could occur on the ground in emergencies if people were using N-numbers that were different from the ones painted on their aircraft. The theory is that if you're using a Flight ID, there is no confusion for first responders because they don't have an N-number to look for on the ramp. Giving them a false N-number could confuse things...although I'm guessing "Go to the aircraft on fire" would overcome that confusion fairly easily.

So, the bottom line is that your best privacy option is to use all three options available at all times: Register your aircraft in the LADD program (free), use a Flight ID ($250-$300 per year), and enroll in the PIA program (currently free, but that may change as the program transitions to an outside program manager). Between all these options, it becomes much more difficult for random people to track your every move, with one exception.

It turns out that there's one big loophole in the PIA program: the Freedom of Information Act. All of this private data can be had with a simple letter sent to the FAA requesting it, and that's exactly what people and companies do. One company in particular sends regular FOIA requests to the FAA in order to sell competitive data to other companies. It simply asks the FAA regularly for a list of all PIA addresses and who they belong to. Then it sells elaborate reports telling companies exactly what ALL their competitors' aircraft are doing at all times. It may be legal, but let's just say that the ethics of this practice are questionable at best.

Unless you're a high-tech company trying to maintain a confidential edge on your competitors, or a celebrity trying to avoid the paparazzi, chances are that you can protect most of your privacy through the programs offered by the FAA. And, perhaps with the help of organizations such as AOPA, EAA and NBAA, we might also get some of the regulations changed to make our pilots and aircraft registration data private as well. While we're at it, the ability to use the PIA program without having to use a Flight ID would be high on my list of requests. Until then, just do what you can and enjoy your freedom to fly. After all, we still have the most vibrant general aviation community on the planet, and the traffic and weather technology that ADS-B has brought to the cockpit has made it safer than ever before. 

Jeff Simon is an A&P mechanic, IA, pilot and aircraft owner, and is the creator of SocialFlight, a free mobile aviation event listing app and website. www.SocialFlight.com.