FlightsAboveMe helps answer a simple question: what aircraft is flying above me right now? It uses live aircraft transponder broadcasts and aviation data feeds to show nearby traffic in a way that’s easy to understand. This page explains what you’re seeing, why some details can be missing, and how the “closest flight” is chosen.

The basics: where live tracking data comes from

Most modern aircraft broadcast small radio messages that include their identity and flight information. The most common is ADS‑B Out (Automatic Dependent Surveillance–Broadcast), typically on 1090 MHz. In the United States, some general aviation aircraft may use 978 MHz (UAT).

Receivers on the ground (often run by aviation enthusiasts) and some satellite systems pick up these broadcasts. Tracking networks combine those receiver reports into live “state vectors” (position, altitude, heading, speed) that apps like FlightsAboveMe can query.

Important: FlightsAboveMe is for informational and educational use only. It is not intended for navigation or operational decision‑making.

How FlightsAboveMe selects the closest flight

When you load the site, the browser may ask for location permission. If you allow it, FlightsAboveMe uses your approximate coordinates to find the nearest aircraft from the live feed. If you deny location, a demo location is used so you can still explore the experience.

• Live feed: Fetch nearby aircraft state vectors.
• Distance check: Compute the distance from you to each aircraft.
• Stability gate: The “closest” result must persist across multiple update cycles to avoid flicker.
• Limits: Very distant or low-confidence results may be excluded.
• Non‑blocking enrichment: Extra details load in the background and never delay the main render.

What the fields mean (and why some hide)

Different aircraft and different networks report different levels of detail. FlightsAboveMe intentionally hides fields that are unavailable rather than guessing. Common fields include:

• Callsign: The flight identifier (often an airline flight number, but not always).
• ICAO24: A unique 24‑bit aircraft address used by Mode S transponders.
• Altitude: Usually pressure altitude; see the altitude section below.
• Vertical speed (phase): Shown as Climbing, Descending, or Cruising for readability.
• Route / aircraft model: Shown only when confidently available from enrichment sources.

Why trackers disagree (and why a plane may not appear)

If you compare multiple flight tracking sites, you’ll sometimes see differences. That’s normal. Most disagreements come from a few real‑world factors:

• Receiver coverage: ADS‑B is line‑of‑sight. Terrain, buildings, and distance affect what can be received.
• Latency: Feeds update at different rates and may apply different smoothing or filtering.
• MLAT estimates: If an aircraft isn’t broadcasting full position, some networks estimate position via multilateration (MLAT).
• Aircraft behavior: Some aircraft transmit limited data, change callsigns, or may be filtered for privacy/security reasons.

Low‑altitude aircraft can also “drop out” behind terrain, and rural areas may have fewer receivers. That’s why FlightsAboveMe supports a demo mode when location is unavailable.

Altitude: flight levels vs “feet”

Altitude in live tracking feeds is typically based on pressure altitude (barometric altitude), especially at higher altitudes. That’s why you may see values that don’t perfectly match local terrain elevation or GPS altitude. At cruise, aircraft often fly in standardized flight levels (for example, “FL350” ≈ 35,000 feet).

Want a deeper explanation? See the dedicated page: Altitude explained.

Squawk codes: why FlightsAboveMe shows meaning

A squawk is a four‑digit transponder code assigned by air traffic control. Some codes have special, widely known meanings (for example, emergency, radio failure, or unlawful interference).

To keep the UI clear and avoid showing cryptic numbers without context, FlightsAboveMe displays the meaning when known, and hides the field when it’s not relevant. Learn more here: Squawk codes explained.

Data sources and enrichment

FlightsAboveMe blends multiple sources to improve reliability and add aircraft details:

• OpenSky Network — primary live state vectors when available
• adsb.lol — fallback live aircraft state data
• AeroDataBox — aircraft enrichment (type/model/operator details)

Enrichment is intentionally conservative: if a detail isn’t available with reasonable confidence, it stays hidden. This keeps the experience clean and reduces incorrect assumptions.

For a fuller transparency note (and accuracy limitations), see: Data Sources & Accuracy.

Build your own ADS‑B receiver

Want to see aircraft with your own antenna? A small USB SDR and an outdoor antenna can receive ADS‑B signals locally. Receivers like this are how community networks build coverage. Start here: Build an ADS‑B receiver.

Important notice

Flight data is provided for informational purposes only and may be delayed, incomplete, or inaccurate. Not for operational or navigation use.