Signal Intelligence - Wind & Wireless

ACTIVE SIGNALS: WHAT MAKES AN AIRCRAFT WORTH TRACKING?

When it comes to plane spotting it's about recognizing the exceptional. Here's how to separate routine traffic from genuinely interesting signals.

Primary Tracking Resources

Your Digital Control Tower & Community Hub

Every spotter needs tools and community. These are the essential starting points for modern signal intelligence.

Essential Sig Int Links

ADS-B Exchange

The unfiltered, crowd-sourced global aircraft tracking map. See military, government, and blocked aircraft that don't appear on commercial sites. Real-time data with historical playback.

r/aviation

The central hub for aircraft spotters, pilots, and enthusiasts. Share catches, identify mysteries, and discuss everything from commercial heavies to rare military movements.

r/ADSB

Focused specifically on ADS-B tracking. The go-to place for identifying unusual hex codes, mysterious tracks, and understanding the data behind the signals.

Pro Tip: Cross-Reference

When you see something interesting on ADS-B Exchange, check its registration or callsign against databases like FlightAware or Planespotters.net for photos and ownership history. Then, search Reddit to see if others have spotted it too.

Performance Extremes

Fast, High, Slow, Low – The Numbers That Stand Out

Deviations from normal flight profiles are immediate attention-grabbers. These metrics tell a story of urgency, capability, or special mission profiles.

The Performance Spectrum

Commercial and general aviation have norms. When aircraft operate outside these envelopes, it's worth investigating why.

Fast

Mach 0.85+ for airliners indicates strong tailwinds or urgent scheduling. Military jets > Mach 1.5 (visible as sonic boom reports) are training or rapid response. Supersonic business jets (like the upcoming Boom Overture) will be instant highlights.

High

Commercial jets cruise at 30,000-40,000 ft. Aircraft above 45,000 ft are often bizjets (G650, Global Express) or specialized (U-2, ER-2). >60,000 ft is exclusive to military reconnaissance (SR-71 heritage missions) or test aircraft.

Slow

Airliners below 180 knots are likely in holding patterns or final approach. Extremely slow speeds for type (e.g., a heavy cargo plane at 120 knots) might indicate engine issues, heavy drag (open cargo door), or special aerial work like mapping.

Low

Civilian traffic below 1,000 ft AGL away from airports is unusual. This includes low-level military training routes ("Low ALTRV"), search and rescue, pipeline/powerline inspection, or media helicopters. Sudden low altitude can also signal an emergency.

Real-World Catch: The High & Mighty

An aircraft squawking a discrete code (like 0010) at FL510 (51,000 ft) over the midwestern US is almost certainly a NASA ER-2 (civilian U-2) or a Northrop Grumman test bed. Its altitude alone makes it a rare track worth logging and sharing.

Rarity & Anomalies

"This Doesn't Belong Here" – The Ultimate Trigger

Sometimes the aircraft itself, its location, or its mission creates the intrigue. These are the catches that make spotters grab their cameras.

The Unusual & Significant

Rarity comes in many forms, from the airframe itself to who or what is on board.

Out-of-Place Aircraft

A Qantas 747 over Kansas, an Icelandic Coast Guard Dash-8 in the Mediterranean, or South African Air Force C-130 in the Arctic. Unusual operators in unusual places often signal deployments, exercises, or ferry flights for maintenance/sale.

VIP/Mission-Specific

Aircraft with special callsigns (AF1, SAM, VVIP), or unique configurations (airborne command posts like the E-4B Nightwatch or E-6B Mercury). Also includes "Janet" flights (unmarked 737s to secret test sites) or NASA's "WB-57" high-altitude research planes.

Fleet Rarity

When only a handful of airframes exist. Examples: The Antonov An-225 Mriya (RIP, only one existed), the Airbus BelugaST/Super Guppy, the Boeing 747 Dreamlifter, or the last flying DC-3s in scheduled service. Every sighting is an event.

Historical & Wartime

Active-duty B-52 Stratofortresses (entering 100 years of service), the occasional B-2 Spirit training sortie, or World War II warbirds on cross-country trips. These are flying history and always draw attention.

The Ultimate Catch: "Air Force One"

Any VC-25 (Boeing 747-200) with the callsign AF1 (when the President is on board) or SAM (Special Air Mission) is the pinnacle. Its route, fighter escort (if over land), and support aircraft (C-17s with vehicles, C-32s for staff) tell a full logistical story.

Formation & Group Behavior

"The Whole is Greater Than the Sum of Its Parts"

A single interesting aircraft is great, but multiple aircraft acting in concert reveal exercises, deployments, or operations.

Collective Movements

Formations and groups break the pattern of solitary commercial flight, indicating coordinated purpose.

Tactical Formations

Pairs or fourships of fighter jets (F-15, F-16, F-22, F-35) flying identical tracks at close proximity. Tankers (KC-135, KC-10, KC-46) orbiting with receivers indicate aerial refueling tracks, often for long-distance deployments or endurance training.

Deployment Packages

Multiple heavy aircraft (C-17s, C-130s) flying the same route across an ocean, often spaced minutes apart. This signals a unit movement or exercise setup. A "package" might include a commercial charter (Omni, Atlas) for personnel alongside military cargo planes.

Test & Support Fleets

A unique aircraft (like a Boeing 777X or NASA X-59) flying with a "chase plane" (often a T-38 or company jet) to observe and photograph. NASA's SOFIA (retired 747 telescope) often flew with a companion aircraft for calibration.

Rotary-Wing Armadas

A stream of Army Chinooks or Black Hawks flying at low level along a training route. Or, a Navy carrier strike group's worth of helicopters (MH-60Rs, MH-53Es) transiting coastally between bases and ships.

Reading the Exercise: "Red Flag" or "Maple Flag"

During major exercises, you'll see diverse aircraft from allied nations converging on a single area (like Nellis AFB). Tracks show AWACS (E-3 Sentry) orbiting as "quarterbacks," with tankers holding nearby, and numerous fighter tracks merging into a complex "air battle" area. The mix of USAF, USN, and international aircraft tells the story.

The Spotter's Mindset

Signal intelligence is about pattern recognition. The first step is learning the normal patterns: the daily airline flows, the standard business jet routes, the local training patterns. Once you know what's routine, the exceptional—the fast, high, slow, low, rare, and coordinated—screams for attention.

Build Your Knowledge Base

Learn the common hex codes (ICAO 24-bit addresses) for local aircraft. Bookmark the Scramble.nl database for military aircraft serials. Understand basic callsign schemes: "REACH" for USAF Air Mobility Command, "NAVY" for US Navy, "HAF" for Hellenic Air Force, etc.

Share & Collaborate

The community solves mysteries. When you catch something you can't identify, a screenshot on r/ADSB or Twitter/X with the hex code, callsign, and track often yields an answer within minutes from experts worldwide. Your obscure catch might be someone else's specialty.

Next Sig Int Update: This week's interesting catches from the global tracking network and how to interpret unusual flight paths.