The Los Angeles County Assessor's Office says its Situs Hawk aircraft-discovery platform draws on ADS-B data, among other sources, to find aircraft that owe property tax. The county has not said which data feeds it uses or how it handles owners who opted into FAA privacy programs.
We must go back to the early 2000s, when the FAA tried to sell this ADS-B claptrap as a feature that would make the NAS safer. No, the FAA wasn’t being proactive. Some serious shenanigans were going on down at HQ when it came to the GA safety numbers. Ginned up improved safety numbers is an understatement, as the GATAA survey data was being twisted and manipulated (or personipulated for the Uncrewed crowd), in ways that would call the whole dog and pony show into question.
ADS-B couldn’t fix abysmal safety numbers alone, so the FAA decided to add all aircraft registered in the previous 10 years to the data returned by GAATA survey takers. A small percentage of the GA flyers send in some numbers from memory for flights over the last year. The FAA takes those numbers and times them by the number of registered aircraft and viola, you’ve got 10-6.
Why are these dawn of time digression necessary? The FAA runs on data! The droners were told that the FAA couldn’t use data from illegal operations. Being out of registration for 7 years is not compliance. It gets worse. How could it get worse? Well, the FAA lost about 119,000 aircraft from the registration rolls. One year, they had to pull a Mulligan, and the safety of the NAS numbers is blank.
https://www.cbsnews.com/news/faa-missing-info-on-119000-planes/
The Los Angeles County Assessor's Office has confirmed that it uses ADS-B data, the position reports that most U.S. aircraft must broadcast, to find aircraft it says have escaped property taxation.
"The Los Angeles County Assessor's Office has invested in advanced aircraft discovery software, Situs Hawk, that analyzes multiple data sources, including data from ADS-B, to identify aircraft activity at local airports," Stephen R. Whitmore, the office's public information officer, said in an email to UASNEWSUS.com on Oct. 7. "This technology enables the County to locate and assess aircraft that previously escaped taxation, ensuring that all property owners are treated equitably and that the tax burden is fairly shared."
The county's March 16, 2026 press release described the same software only as analyzing "multiple data sources." It named neither the vendor nor ADS-B. Whitmore's email names both. Maybe the FAA should use this software to collect registration information?
On March 3, 2026, the Assessor asked the Board of Supervisors to approve $700,000 in one-time money from the county's Information Technology Infrastructure Fund for a one-year "aircraft discovery and audit service subscription." The county's IT Investment Board had approved the funding on Sept. 25, 2025. The board letter says the service will provide "real-time lists of aircraft with tax liabilities," "defensible materials for appraisal and appeal," and auto-generated inquiry and billing letters. It also says later years are "expected to be offset by revenue generated from the service." The letter does not name the vendor. According to a lobbying-disclosure aggregator, Situs Hawk does business as SH Advisors, LLC, an Alabama firm.
The county said in March that since the program began in January 2026, it had found "nearly 1,000 previously unassessed aircraft." It projected nearly $2.5 billion in escaped assessed value from prior years, more than $1 billion in new 2026 assessments, and about $38 million in additional property tax revenue. When it comes to tax revenue or regulatory fines, the California government is a diligent as a spiteful tick on a preverbal hound dog.
"California law is clear, aircraft are taxable based on where they are primarily located and operated, not where they are registered," Whitmore wrote. The board letter cites Revenue and Taxation Code Section 404 and Property Tax Rule 205(b) as its situs standard. In a statement published by AvBrief, Assessor Jeff Prang said that "simply flying into Los Angeles County does not make an aircraft subject to property tax here." He pointed to the Board of Equalization's Assessors' Handbook Section 577 for the "habitually situated" test. California's property tax lien date is Jan. 1. You don’t want to get sideways with these folks!
Whitmore also blamed federal changes for part of the problem: "changes in how aircraft ownership information is maintained by the Federal Aviation Administration (FAA) have made it more difficult for local government agencies to identify aircraft activity and ownership." He did not name the changes. The likely candidates are below.
Registry privacy. Section 803 of the FAA Reauthorization Act of 2024 (P.L. 118-63) led the FAA, starting March 28, 2025, to let private owners ask that their names and addresses be withheld from FAA websites under 49 U.S.C. § 44114(b). The FAA said it was also weighing whether to withhold that information by default.
LADD. The Limiting Aircraft Data Displayed program removes an aircraft's flight data from the FAA's SWIM feed and from participating tracking websites. The FAA says plainly that LADD "does not impact the ADS-B broadcast data."
PIA. The Privacy ICAO Address program gives eligible aircraft a temporary alternate ICAO address that is not tied to the owner in the registry.
Golly, can I get some of that for drone RID too?
Taken together: LADD hides flights from FAA-sourced feeds but not from anyone with a receiver, and PIA hides the owner but not the broadcast. That gap matters most for unfiltered, crowdsourced networks. Whitmore's email included background on one of them, ADS-B Exchange, which it described as crowdsourced, unfiltered flight tracking founded in 2016. The email did not say the county or Situs Hawk uses ADS-B Exchange. UASNEWSUS.com has asked for follow-up, and the question is open.
AvWeb reported on Aug. 12, 2026, that California pilots are challenging the practice. It also reported that Prang wrote in a Wall Street Journal letter that limiting government access to public data would shift the tax burden onto other taxpayers. GlobalAir and AvBrief have covered the program, and AvBrief updated its story with comment from AOPA. Lobbying filings list Situs Hawk as lobbying on the Pilot and Aircraft Privacy (PAPA) Act, the ALERT Act, and the ROTOR Act. The filings do not say what position the company took.
Privacy matters? Congress and the FAA have spent several years giving private owners ways to limit public exposure. The county's position is that its job is uniform enforcement and that aircraft owners should be assessed like any other property owner. As of Jan. 1, 2020, ADS-B is required in most controlled airspace under 14 CFR 91.225 and was sold to operators as a safety and efficiency tool. Using it as a revenue tool tests the bargain operators thought they made, but the weather feature is nice.
"Multiple data sources" could mean FAA feeds, commercial aggregators, airport records, or crowdsourced receivers, and each has different privacy implications. How the county handles LADD and PIA aircraft, and how reliable its evidence is for situs findings and appeals, are central questions. The board letter itself describes the output as "defensible materials for appraisal and appeal." It makes you feel warm and fuzzy while you cut the check.
The UAS precedent. Under 14 CFR Part 89, most drones must broadcast Remote ID, including identity and location. Nothing reviewed for this story shows any jurisdiction using Remote ID for taxes or enforcement. Still, L.A. County's approach is a working example of a mandated safety broadcast being reused as fiscal-enforcement data. Drone fleet operators and policymakers may want to ask whether Remote ID data could be used the same way later. Several UTM service providers planned to collect landing and take-off fees to pay back their VC investors. Well, until DJI had a little FAA buy-in and put the kibosh on anyone cutting in on their vertical RID integration scheme.
Maybe we should ask the Assessor’s office if they have any ideas on UTM? Maybe throw them the takeoff-and-landing-fee-generation bone and see what these earnest innovators come up with?
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