Apparatus

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sensors Mode-S transponder

A0543B

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N120FM · operated by RUNAMUCK LLC

Hex
A0543B
Octal
50052073
Decimal
10,507,323
Country
US
Tail
N120FM
Type
C172
No current signal · last broadcast 1h ago
Flights observed
266
Distinct callsigns
1
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S A0543B.

Country allocation

The ICAO 24-bit address A0543B 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
N120FM - 266 2026-07-14

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 N120FM BJC → BJC Jul 14, 02:50 UTCJul 14, 05:20 UTC2h 30m
2026-07-13 N120FM BJC → BJC Jul 13, 19:00 UTCJul 13, 20:30 UTC1h 30m
2026-07-13 N120FM BJC → BJC Jul 13, 16:25 UTCJul 13, 17:20 UTC55m
2026-07-13 N120FM BJC → BJC Jul 13, 14:00 UTCJul 13, 15:25 UTC1h 25m
2026-07-12 N120FM BJC → BJC Jul 12, 20:30 UTCJul 12, 21:15 UTC45m
2026-07-12 N120FM BJC → BJC Jul 12, 16:05 UTCJul 12, 17:45 UTC1h 40m
2026-07-12 N120FM BJC → BJC Jul 12, 12:30 UTCJul 12, 14:20 UTC1h 50m
2026-07-10 N120FM BJC → BJC Jul 10, 15:25 UTCJul 10, 16:20 UTC55m
2026-07-10 N120FM BJC → BJC Jul 10, 13:05 UTCJul 10, 14:10 UTC1h 5m
2026-07-10 N120FM BJC → BJC Jul 10, 06:25 UTCJul 10, 08:35 UTC2h 10m
2026-07-09 N120FM BJC → BJC Jul 9, 19:00 UTCJul 9, 20:25 UTC1h 25m
2026-07-09 N120FM BJC → BJC Jul 9, 16:30 UTCJul 9, 17:05 UTC35m
2026-07-09 N120FM BJC → BJC Jul 9, 12:50 UTCJul 9, 14:55 UTC2h 5m
2026-07-09 N120FM BJC → BJC Jul 9, 02:05 UTCJul 9, 02:50 UTC45m
2026-07-08 N120FM BJC → BJC Jul 8, 15:55 UTCJul 8, 17:20 UTC1h 25m
2026-07-08 N120FM BJC → BJC Jul 8, 13:55 UTCJul 8, 14:50 UTC55m
2026-07-07 N120FM BJC → BJC Jul 7, 17:30 UTCJul 7, 18:45 UTC1h 15m
2026-07-07 N120FM BJC → BJC Jul 7, 12:05 UTCJul 7, 14:00 UTC1h 55m
2026-07-07 N120FM BJC → BJC Jul 7, 02:05 UTCJul 7, 02:55 UTC50m
2026-07-06 N120FM BJC → BJC Jul 6, 21:10 UTCJul 6, 22:40 UTC1h 30m
2026-07-06 N120FM BJC → BJC Jul 6, 16:20 UTCJul 6, 17:55 UTC1h 35m
2026-07-06 N120FM BJC → BJC Jul 6, 13:00 UTCJul 6, 14:25 UTC1h 25m
2026-07-06 N120FM BJC → BJC Jul 6, 02:10 UTCJul 6, 03:45 UTC1h 35m
2026-07-06 N120FM BJC → BJC Jul 6, 00:00 UTCJul 6, 00:55 UTC55m
2026-07-05 N120FM BJC → BJC Jul 5, 20:30 UTCJul 5, 22:00 UTC1h 30m
2026-07-05 N120FM - Jul 5, 17:30 UTCJul 5, 18:25 UTC55m
2026-07-05 N120FM - Jul 5, 15:10 UTCJul 5, 16:40 UTC1h 30m
2026-07-04 N120FM BJC → BJC Jul 4, 17:10 UTCJul 4, 18:10 UTC1h 0m
2026-07-04 N120FM BJC → BJC Jul 4, 14:40 UTCJul 4, 15:40 UTC1h 0m
2026-07-03 N120FM BJC → BJC Jul 3, 22:00 UTCJul 3, 23:30 UTC1h 30m
2026-07-03 N120FM BJC → BJC Jul 3, 20:00 UTCJul 3, 20:05 UTC5m
2026-07-03 N120FM BJC → BJC Jul 3, 17:15 UTCJul 3, 18:15 UTC1h 0m
2026-07-03 N120FM BJC → BJC Jul 3, 14:35 UTCJul 3, 16:10 UTC1h 35m
2026-07-03 N120FM BJC → BJC Jul 3, 12:20 UTCJul 3, 13:35 UTC1h 15m
2026-07-03 N120FM BJC → BJC Jul 3, 04:30 UTCJul 3, 06:15 UTC1h 45m
2026-07-02 N120FM BJC → BJC Jul 2, 21:45 UTCJul 2, 22:20 UTC35m
2026-07-02 N120FM - Jul 2, 13:50 UTCJul 2, 14:25 UTC35m
2026-07-02 N120FM - Jul 2, 13:25 UTCJul 2, 13:30 UTC5m
2026-07-02 N120FM - Jul 2, 13:05 UTCJul 2, 13:20 UTC15m
2026-07-02 N120FM BJC → BJC Jul 2, 01:25 UTCJul 2, 03:05 UTC1h 40m
2026-07-01 N120FM BJC → BJC Jul 1, 20:25 UTCJul 1, 22:30 UTC2h 5m
2026-07-01 N120FM - Jul 1, 17:55 UTCJul 1, 18:50 UTC55m
2026-07-01 N120FM BJC → BJC Jul 1, 15:30 UTCJul 1, 17:10 UTC1h 40m
2026-07-01 N120FM BJC → BJC Jul 1, 11:45 UTCJul 1, 12:50 UTC1h 5m
2026-06-30 N120FM COS → BJC Jun 30, 19:25 UTCJun 30, 20:10 UTC45m
2026-06-30 N120FM BJC → COS Jun 30, 18:30 UTCJun 30, 19:20 UTC50m
2026-06-30 N120FM BJC → BJC Jun 30, 15:50 UTCJun 30, 17:20 UTC1h 30m
2026-06-30 N120FM BJC → BJC Jun 30, 12:30 UTCJun 30, 14:20 UTC1h 50m
2026-06-30 N120FM - Jun 30, 05:00 UTCJun 30, 05:45 UTC45m
2026-06-30 N120FM - Jun 30, 02:20 UTCJun 30, 03:15 UTC55m

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 N120FM page for operator, model, and routing details .

Mode-S A0543B frequently asked

What is Mode-S code A0543B?
A0543B is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N120FM.
Where is Mode-S A0543B registered?
Mode-S code A0543B 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 A0543B broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A0543B, octal 50052073, decimal 10,507,323.
What flights does A0543B operate?
Mode-S A0543B has broadcast 1 distinct callsign, including N120FM.