sensors Mode-S transponder

514521

ICAO 24-bit transponder address

Hex
514521
Octal
24242441
Decimal
5,326,113
No current signal · last broadcast 10d ago
Flights observed
14
Distinct callsigns
1
Country
-
Last broadcast
10d ago

Last known position

Most recent position reported by Mode-S 514521.

Callsign history 1 distinct

Callsign Airline Flights Last seen
N507DG - 14 2026-07-26

Recent flights last 14

DateFlightRouteTakeoffLandingDuration
2026-07-26 N507DG - Jul 26, 20:55 UTCJul 26, 21:30 UTC35m
2026-07-24 N507DG - Jul 24, 03:30 UTCJul 24, 04:05 UTC35m
2026-07-09 N507DG - Jul 9, 20:10 UTCJul 9, 20:20 UTC10m
2026-07-09 N507DG - Jul 9, 19:40 UTCJul 9, 19:50 UTC10m
2026-07-07 N507DG - Jul 7, 23:25 UTCJul 8, 00:00 UTC35m
2026-07-07 N507DG - Jul 7, 20:40 UTCJul 7, 21:15 UTC35m
2026-06-28 N507DG - Jun 28, 03:05 UTCJun 28, 03:35 UTC30m
2026-06-27 N507DG - Jun 27, 02:09 UTCJun 27, 02:45 UTC35m
2026-06-21 N507DG - Jun 21, 22:44 UTCJun 21, 23:14 UTC30m
2026-06-21 N507DG - Jun 21, 18:25 UTCJun 21, 18:54 UTC30m
2026-06-20 N507DG - Jun 20, 21:05 UTCJun 20, 21:14 UTC10m
2026-06-20 N507DG - Jun 20, 18:29 UTCJun 20, 18:40 UTC10m
2026-06-17 N507DG - Jun 17, 22:25 UTCJun 17, 22:35 UTC10m
2026-06-17 N507DG - Jun 17, 20:45 UTCJun 17, 21:00 UTC15m

About Mode-S

A Mode-S transponder code (also called an "ICAO 24-bit address" or "hex code") is a 6-character hexadecimal identifier permanently assigned to an aircraft when it's first registered. Unlike callsigns (which change with each flight) or registrations (which can change if an aircraft is sold internationally), the Mode-S address stays with the airframe for the life of the aircraft in that country.

Every ADS-B transmission from an aircraft includes its Mode-S address, making it the most reliable way to identify a specific airframe. Flight-tracking services like Apparatus use the Mode-S address as the primary key for tying position broadcasts, callsigns, and ownership records together.

Mode-S 514521 frequently asked

What is Mode-S code 514521?
514521 is an ICAO 24-bit transponder address.
Is 514521 broadcasting right now?
No active broadcast right now. Last signal was 10d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 514521, octal 24242441, decimal 5,326,113.
What flights does 514521 operate?
Mode-S 514521 has broadcast 1 distinct callsign, including N507DG.