Apparatus

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sensors Mode-S transponder

A1C403

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N2125M · CESSNA 172R Cutlass RG · operated by NFH AVIATION LLC

Hex
A1C403
Octal
50342003
Decimal
10,601,475
Country
US
Tail
N2125M
Type
C72R
No current signal · last broadcast 13d ago
Flights observed
97
Distinct callsigns
1
Country
US
Last broadcast
13d ago

Last known position

Most recent position reported by Mode-S A1C403.

Country allocation

The ICAO 24-bit address A1C403 falls within the block assigned to United States (US) by ICAO Annex 10, Volume III. Every aircraft registered in United States receives a permanent address from this block at the time of registration; the address stays with the airframe even if the aircraft is re-registered to a different operator within the country.

Callsign history 1 distinct

Callsign Airline Flights Last seen
N2125M - 95 2026-07-26

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 N2125M - Jul 26, 19:15 UTCJul 26, 20:05 UTC50m
2026-07-26 N2125M - Jul 26, 17:25 UTCJul 26, 17:35 UTC10m
2026-07-26 N2125M - Jul 26, 16:10 UTCJul 26, 16:35 UTC25m
2026-07-26 N2125M - Jul 26, 15:10 UTCJul 26, 15:20 UTC10m
2026-07-25 N2125M - Jul 25, 19:45 UTCJul 25, 20:20 UTC35m
2026-07-25 N2125M - Jul 25, 15:35 UTCJul 25, 15:45 UTC10m
2026-07-25 N2125M - Jul 25, 13:30 UTCJul 25, 14:40 UTC1h 10m
2026-07-25 N2125M - Jul 25, 11:00 UTCJul 25, 11:35 UTC35m
2026-07-24 N2125M - Jul 24, 18:40 UTCJul 24, 18:55 UTC15m
2026-07-24 N2125M - Jul 24, 16:00 UTCJul 24, 16:30 UTC30m
2026-07-23 N2125M - Jul 23, 22:15 UTCJul 23, 22:40 UTC25m
2026-07-23 - - Jul 23, 20:05 UTCJul 23, 20:15 UTC10m
2026-07-22 N2125M - Jul 22, 17:15 UTCJul 22, 17:45 UTC30m
2026-07-20 N2125M - Jul 20, 17:20 UTCJul 20, 18:05 UTC45m
2026-07-19 N2125M - Jul 19, 21:20 UTCJul 19, 22:55 UTC1h 35m
2026-07-19 N2125M - Jul 19, 20:00 UTCJul 19, 20:25 UTC25m
2026-07-17 N2125M - Jul 17, 17:50 UTCJul 17, 18:19 UTC30m
2026-07-16 N2125M - Jul 16, 21:25 UTCJul 16, 21:55 UTC30m
2026-07-16 N2125M - Jul 16, 18:10 UTCJul 16, 18:29 UTC20m
2026-07-15 N2125M - Jul 15, 15:45 UTCJul 15, 16:30 UTC45m
2026-07-15 N2125M PVL → PVL Jul 15, 14:00 UTCJul 15, 14:50 UTC50m
2026-07-09 N2125M - Jul 9, 18:30 UTCJul 9, 19:15 UTC45m
2026-07-08 N2125M - Jul 8, 17:50 UTCJul 8, 18:20 UTC30m
2026-07-01 N2125M - Jul 1, 17:00 UTCJul 1, 17:15 UTC15m
2026-07-01 N2125M - Jul 1, 14:35 UTCJul 1, 15:35 UTC1h 0m
2026-07-01 N2125M - Jul 1, 12:05 UTCJul 1, 12:50 UTC45m
2026-06-30 N2125M - Jun 30, 23:40 UTCJul 1, 00:30 UTC50m
2026-06-30 N2125M - Jun 30, 21:45 UTCJun 30, 22:05 UTC20m
2026-06-30 N2125M - Jun 30, 20:15 UTCJun 30, 20:50 UTC35m
2026-06-30 N2125M PVL → PVL Jun 30, 16:25 UTCJun 30, 16:35 UTC10m
2026-06-29 N2125M PVL → PVL Jun 29, 17:55 UTCJun 29, 18:19 UTC25m
2026-06-25 N2125M - Jun 25, 15:29 UTCJun 25, 16:20 UTC50m
2026-06-25 N2125M - Jun 25, 13:40 UTCJun 25, 13:55 UTC15m
2026-06-24 N2125M - Jun 24, 16:54 UTCJun 24, 17:25 UTC30m
2026-06-24 N2125M - Jun 24, 15:35 UTCJun 24, 16:05 UTC30m
2026-06-20 N2125M - Jun 20, 12:04 UTCJun 20, 12:30 UTC25m
2026-06-19 N2125M - Jun 19, 14:59 UTCJun 19, 15:14 UTC15m
2026-06-17 N2125M - Jun 17, 16:50 UTCJun 17, 17:00 UTC10m
2026-06-16 N2125M PVL → PVL Jun 16, 14:55 UTCJun 16, 15:50 UTC55m
2026-06-16 N2125M - Jun 16, 12:20 UTCJun 16, 13:50 UTC1h 30m
2026-06-14 N2125M - Jun 14, 19:55 UTCJun 14, 20:15 UTC20m
2026-06-13 N2125M - Jun 13, 22:05 UTCJun 13, 22:45 UTC40m
2026-06-13 N2125M - Jun 13, 19:15 UTCJun 13, 20:05 UTC50m
2026-06-13 N2125M - Jun 13, 17:35 UTCJun 13, 18:20 UTC45m
2026-06-12 N2125M - Jun 12, 18:30 UTCJun 12, 19:15 UTC45m
2026-06-12 N2125M PVL → PVL Jun 12, 15:35 UTCJun 12, 16:20 UTC45m
2026-06-11 N2125M - Jun 11, 21:20 UTCJun 11, 22:00 UTC40m
2026-06-11 N2125M - Jun 11, 17:55 UTCJun 11, 18:10 UTC15m
2026-06-11 N2125M - Jun 11, 13:30 UTCJun 11, 14:30 UTC1h 0m
2026-06-11 N2125M - Jun 11, 10:30 UTCJun 11, 11:05 UTC35m

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.

Prefer a tail-number view? See the N2125M page for operator, model, and routing details .

Mode-S A1C403 frequently asked

What is Mode-S code A1C403?
A1C403 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N2125M.
Where is Mode-S A1C403 registered?
Mode-S code A1C403 is allocated to United States (US). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is A1C403 broadcasting right now?
No active broadcast right now. Last signal was 13d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1C403, octal 50342003, decimal 10,601,475.
What flights does A1C403 operate?
Mode-S A1C403 has broadcast 1 distinct callsign, including N2125M.