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 2d ago
Flights observed
124
Distinct callsigns
1
Country
US
Last broadcast
2d 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 - 124 2026-05-27

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-27 N120FM - May 27, 17:10 UTCMay 27, 17:40 UTC30m
2026-05-26 N120FM BJC → BJC May 26, 18:19 UTCMay 26, 20:00 UTC1h 40m
2026-05-26 N120FM BJC → BJC May 26, 15:14 UTCMay 26, 16:40 UTC1h 25m
2026-05-26 N120FM - May 26, 05:05 UTCMay 26, 06:14 UTC1h 10m
2026-05-26 N120FM - May 26, 03:30 UTCMay 26, 04:24 UTC55m
2026-05-25 N120FM BJC → BJC May 25, 14:55 UTCMay 25, 15:40 UTC45m
2026-05-25 N120FM BJC → BJC May 25, 12:15 UTCMay 25, 13:00 UTC45m
2026-05-24 N120FM BJC → BJC May 24, 17:20 UTCMay 24, 18:50 UTC1h 30m
2026-05-24 N120FM BJC → BJC May 24, 15:05 UTCMay 24, 16:30 UTC1h 25m
2026-05-24 N120FM BJC → BJC May 24, 12:10 UTCMay 24, 13:05 UTC55m
2026-05-23 N120FM BJC → BJC May 23, 17:25 UTCMay 23, 18:25 UTC1h 1m
2026-05-23 N120FM BJC → BJC May 23, 14:30 UTCMay 23, 16:20 UTC1h 50m
2026-05-22 N120FM - May 22, 22:10 UTCMay 22, 23:15 UTC1h 5m
2026-05-22 N120FM - May 22, 21:00 UTCMay 22, 21:35 UTC35m
2026-05-22 N120FM BJC → BJC May 22, 17:45 UTCMay 22, 18:55 UTC1h 10m
2026-05-22 N120FM BJC → BJC May 22, 16:00 UTCMay 22, 16:55 UTC55m
2026-05-22 N120FM BJC → BJC May 22, 13:40 UTCMay 22, 14:55 UTC1h 15m
2026-05-21 N120FM - May 21, 20:25 UTCMay 21, 21:20 UTC55m
2026-05-21 N120FM BJC → BJC May 21, 17:55 UTCMay 21, 19:35 UTC1h 40m
2026-05-21 N120FM BJC → BJC May 21, 15:15 UTCMay 21, 16:25 UTC1h 10m
2026-05-21 N120FM BJC → BJC May 21, 13:15 UTCMay 21, 14:20 UTC1h 5m
2026-05-21 N120FM BJC → BJC May 21, 03:10 UTCMay 21, 03:45 UTC35m
2026-05-20 N120FM BJC → BJC May 20, 18:50 UTCMay 20, 21:35 UTC2h 45m
2026-05-17 N120FM BJC → BJC May 17, 14:50 UTCMay 17, 16:05 UTC1h 15m
2026-05-17 N120FM BJC → BJC May 17, 01:05 UTCMay 17, 01:50 UTC45m
2026-05-16 N120FM BJC → BJC May 16, 17:55 UTCMay 16, 19:20 UTC1h 25m
2026-05-16 N120FM BJC → BJC May 16, 14:41 UTCMay 16, 16:45 UTC2h 5m
2026-05-15 N120FM BJC → BJC May 15, 22:00 UTCMay 15, 23:40 UTC1h 40m
2026-05-15 N120FM BJC → BJC May 15, 19:45 UTCMay 15, 20:45 UTC1h 0m
2026-05-15 N120FM BJC → BJC May 15, 17:35 UTCMay 15, 18:35 UTC1h 0m
2026-05-15 N120FM BJC → BJC May 15, 15:30 UTCMay 15, 16:20 UTC50m
2026-05-15 N120FM BJC → BJC May 15, 12:50 UTCMay 15, 14:05 UTC1h 15m
2026-05-14 N120FM BJC → BJC May 14, 21:00 UTCMay 14, 22:15 UTC1h 15m
2026-05-14 N120FM BJC → BJC May 14, 13:40 UTCMay 14, 14:30 UTC50m
2026-05-13 N120FM BJC → BJC May 13, 23:05 UTCMay 14, 00:40 UTC1h 35m
2026-05-13 N120FM BJC → BJC May 13, 20:50 UTCMay 13, 21:05 UTC15m
2026-05-13 N120FM BJC → BJC May 13, 19:00 UTCMay 13, 20:00 UTC1h 0m
2026-05-13 N120FM BJC → BJC May 13, 16:55 UTCMay 13, 18:00 UTC1h 5m
2026-05-13 N120FM BJC → BJC May 13, 13:35 UTCMay 13, 15:15 UTC1h 40m
2026-05-12 N120FM BJC → BJC May 12, 23:15 UTCMay 13, 00:05 UTC50m
2026-05-12 N120FM BJC → BJC May 12, 19:45 UTCMay 12, 20:25 UTC40m
2026-05-12 N120FM BJC → BJC May 12, 15:25 UTCMay 12, 16:05 UTC40m
2026-05-12 N120FM - May 12, 04:45 UTCMay 12, 05:55 UTC1h 10m
2026-05-12 N120FM - May 12, 03:10 UTCMay 12, 04:05 UTC55m
2026-05-11 N120FM BJC → BJC May 11, 20:50 UTCMay 11, 22:00 UTC1h 10m
2026-05-11 N120FM BJC → BJC May 11, 18:40 UTCMay 11, 19:40 UTC1h 0m
2026-05-11 N120FM BJC → BJC May 11, 16:00 UTCMay 11, 17:30 UTC1h 31m
2026-05-11 N120FM BJC → BJC May 11, 13:55 UTCMay 11, 14:55 UTC1h 0m
2026-05-10 N120FM BJC → BJC May 10, 22:45 UTCMay 10, 23:55 UTC1h 10m
2026-05-09 N120FM BJC → BJC May 9, 18:30 UTCMay 9, 20:30 UTC2h 0m

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 2d 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.