Aircraft Identification: Hex Codes, N-Numbers, and Obfuscation
Tracking deportation flights requires understanding aircraft identification systems and the tactics contractors use to evade monitoring. This guide covers registration research and obfuscation countermeasures.
Aircraft Identification Fundamentals
ICAO 24-Bit Addresses (Hex Codes)
Every aircraft worldwide is assigned a unique 24-bit ICAO address (commonly called a "hex code") hardcoded into its Mode S transponder upon registration.
| Attribute | Description |
|---|---|
| Format | 6-character hexadecimal (e.g., A12345) |
| Assignment | Algorithmically linked to national registry |
| Persistence | Permanent unless re-registered |
| Broadcast | Transmitted via ADS-B/Mode S transponder |
FAA N-Numbers
In the United States, the hex code corresponds to an FAA-issued registration number (N-number):
| Attribute | Description |
|---|---|
| Format | N + alphanumeric (e.g., N801XT) |
| Registry | FAA Civil Aviation Registry (CAR) |
| Public access | Searchable via FAA databases |
| Relationship | Algorithmically linked to hex code |
Hex Code ↔ N-Number Relationship
N-Number: N801XT
↓ (FAA algorithm)
Hex Code: A12345
↓ (Mode S broadcast)
Tracking Systems
Registration Research
FAA N-Number Registry
The FAA maintains the Civil Aviation Registry containing ownership information for all U.S.-registered aircraft.
| Resource | URL | Data Available |
|---|---|---|
| FAA Registry | registry.faa.gov | Owner, address, aircraft type |
| Releasable Database | FAA download | Bulk registration data |
Research Process
| Step | Action | Purpose |
|---|---|---|
| 1 | Query N-number in FAA registry | Identify registered owner |
| 2 | Research owner entity | Determine if shell company |
| 3 | Cross-reference with contracts | Link to ICE operations |
| 4 | Extract hex code | Enable real-time tracking |
Ownership Obfuscation
Contractors rarely register aircraft under recognizable corporate names:
| Obfuscation Method | Example |
|---|---|
| Holding companies | Slate CRJ Acquisitions 1 LLC |
| Trust entities | [Bank] as Trustee |
| Shell corporations | Generic aviation LLCs |
| Subsidiary layers | Multiple corporate levels |
Obfuscation Tactics
Visual Obfuscation
| Tactic | Description | Examples |
|---|---|---|
| Paint scheme | All-white aircraft, no livery | GlobalX, Avelo aircraft |
| Logo removal | Corporate branding stripped | N801XT, N804VL |
| Generic appearance | Indistinguishable from private charters | — |
Call Sign Obfuscation
| Tactic | Description | Detection |
|---|---|---|
| "RPN" prefix | Repatriate call sign | Filter for RPN* in ATC data |
| Dummy call signs | Non-standard identifiers | Cross-reference with watchlist |
| Commercial mimicry | Standard airline-style calls | Verify against airline schedules |
Electronic Obfuscation
LADD (Limiting Aircraft Data Displayed)
| Attribute | Description |
|---|---|
| Program | FAA privacy initiative |
| Function | Filters aircraft from SWIM data feed |
| Effect | Aircraft disappear from commercial trackers |
| Compliance | FlightAware, FlightRadar24 honor LADD |
| Countermeasure | Use unfiltered networks (ADS-B Exchange) |
PIA (Privacy ICAO Address)
| Attribute | Description |
|---|---|
| Program | Temporary alternate hex code assignment |
| Function | Aircraft broadcasts spoofed identity |
| Effect | Standard watchlist matching fails |
| Countermeasure | Pattern analysis, historical correlation |
Building Aircraft Watchlists
Methodology
| Phase | Action | Data Source |
|---|---|---|
| 1. Seed list | Identify known contractor aircraft | FOIA manifests, contracts |
| 2. Expansion | Add aircraft from same operators | FAA registry queries |
| 3. Correlation | Flag aircraft with ICE hub activity | Historical ADS-B data |
| 4. Verification | Confirm association before publication | Multiple independent sources |
Identification Indicators
| Indicator | Significance |
|---|---|
| Repeated staging hub visits | Mesa, Alexandria, Brownsville |
| "RPN" call sign usage | Repatriate flights |
| LADD/PIA enrollment | Active evasion attempts |
| Operator association | Known contractor fleet |
| Route patterns | Consistent with deportation logistics |
Watchlist Data Structure
{
"hex": "A12345",
"n_number": "N801XT",
"operator": "GlobalX Airlines",
"aircraft_type": "A320-200",
"confidence": "high",
"last_verified": "2026-03-15",
"notes": "International removals",
"sources": ["FOIA", "ADS-B pattern"]
}
FOIA Strategies for Aircraft Identification
Effective Request Targets
| Document Type | Agency | Value |
|---|---|---|
| Flight manifests | ICE ERO | Specific aircraft assignments |
| Contractor invoices | ICE | Aircraft usage billing |
| Contract modifications | DHS | Fleet changes |
| End of Mission reports | ICE Air | Operational details |
Request Language
Pursuant to the Freedom of Information Act, 5 U.S.C. § 552,
I request copies of:
1. All flight manifests for ICE Air Operations from [date range]
2. Aircraft tail numbers (N-numbers) used for removal flights
3. Contractor invoices identifying specific aircraft
4. Any documents identifying ICAO hex codes for charter aircraft
I request a fee waiver as this information serves the public interest
in government transparency.
Handling Denials
| Denial Basis | Response |
|---|---|
| Law enforcement exemption | Appeal; routine logistics are not investigatory |
| Privacy (b)(6) | Request redaction of personal info only |
| Commercial confidential | Challenge; government contracts are public |
| Does not exist | Request retention schedules, reframe request |
Crowdsourced Databases
Available Resources
| Database | Description | Access |
|---|---|---|
| ADS-B Exchange | Unfiltered global aircraft tracking | Public API |
| Witness at the Border | Verified ICE contractor watchlist | Research collaboration |
| OpenSky Network | Academic flight data | Research access |
| UWCHR ARTS data | FOIA-obtained manifests | Published datasets |
Contributing to Watchlists
| Principle | Application |
|---|---|
| Verification required | Multiple sources before adding |
| Document sources | Maintain provenance chain |
| Regular updates | Remove sold/decommissioned aircraft |
| Share responsibly | Vetted researchers only |
Verification Criteria
Before confirming aircraft association with ICE operations:
Required Evidence
| Criterion | Threshold |
|---|---|
| Operator confirmation | Known ICE contractor |
| Route correlation | Activity at staging hubs |
| Call sign evidence | RPN usage documented |
| FOIA documentation | Manifest or contract mention |
| Pattern consistency | Matches deportation logistics |
Confidence Levels
| Level | Requirements |
|---|---|
| High | FOIA documentation + route pattern + operator confirmed |
| Medium | Route pattern + operator confirmed |
| Low | Route pattern only, needs verification |
| Unverified | Single indicator, do not publish |
Ethical Guidelines
Responsible Identification
| Principle | Application |
|---|---|
| Accuracy | Never publish unverified aircraft |
| No misidentification | Private charters are not targets |
| Purpose-limited | Human rights monitoring only |
| No harassment | Do not target flight crews |
| Legal compliance | Work within applicable laws |
Publication Standards
| Before Publishing | Verification Steps |
|---|---|
| Operator confirmed | FAA registry, contracts |
| Route documented | Historical ADS-B data |
| Multiple sources | Independent verification |
| Peer review | Second analyst confirmation |
Related Resources
Last updated: March 25, 2026