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sensors Mode-S transponder

A121A2

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N172LN · CESSNA 172 Skyhawk · operated by FLY AVIATION CORP

Hex
A121A2
Octal
50220642
Decimal
10,559,906
Country
US
Tail
N172LN
Type
C172
Broadcasting now · callsign N172LN · 6,400 ft
Flights observed
230
Distinct callsigns
1
Country
US
Last broadcast
13h ago

Current position

A121A2 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A121A2 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
N172LN - 230 2026-07-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 N172LN - Jul 13, 22:25 UTCJul 13, 23:20 UTC55m
2026-07-13 N172LN - Jul 13, 20:40 UTCJul 13, 21:10 UTC30m
2026-07-13 N172LN - Jul 13, 18:05 UTCJul 13, 19:10 UTC1h 5m
2026-07-13 N172LN - Jul 13, 16:00 UTCJul 13, 17:00 UTC1h 0m
2026-07-13 N172LN FXE → FXE Jul 13, 13:25 UTCJul 13, 13:55 UTC30m
2026-07-12 N172LN - Jul 12, 15:35 UTCJul 12, 16:55 UTC1h 20m
2026-07-12 N172LN - Jul 12, 12:35 UTCJul 12, 13:30 UTC55m
2026-07-12 N172LN - Jul 12, 10:40 UTCJul 12, 11:25 UTC45m
2026-07-11 N172LN - Jul 11, 23:05 UTCJul 12, 01:15 UTC2h 10m
2026-07-11 N172LN - Jul 11, 19:05 UTCJul 11, 21:45 UTC2h 40m
2026-07-11 N172LN - Jul 11, 00:15 UTCJul 11, 02:30 UTC2h 15m
2026-07-10 N172LN - Jul 10, 21:30 UTCJul 10, 23:15 UTC1h 45m
2026-07-10 N172LN FXE → FXE Jul 10, 15:50 UTCJul 10, 17:40 UTC1h 50m
2026-07-09 N172LN COI → FXE Jul 9, 15:15 UTCJul 9, 17:20 UTC2h 5m
2026-07-09 N172LN - Jul 9, 13:50 UTCJul 9, 14:30 UTC40m
2026-07-09 N172LN - Jul 9, 11:00 UTCJul 9, 12:25 UTC1h 25m
2026-07-07 N172LN - Jul 7, 16:40 UTCJul 7, 19:05 UTC2h 25m
2026-07-07 N172LN - Jul 7, 15:00 UTCJul 7, 15:45 UTC45m
2026-07-07 N172LN - Jul 7, 13:30 UTCJul 7, 14:20 UTC50m
2026-07-07 N172LN - Jul 7, 11:40 UTCJul 7, 12:50 UTC1h 10m
2026-07-07 N172LN - Jul 7, 08:10 UTCJul 7, 10:30 UTC2h 20m
2026-07-07 N172LN - Jul 7, 03:55 UTCJul 7, 06:10 UTC2h 15m
2026-07-07 N172LN - Jul 7, 00:35 UTCJul 7, 02:25 UTC1h 50m
2026-07-05 N172LN - Jul 5, 23:15 UTCJul 5, 23:50 UTC35m
2026-07-03 N172LN - Jul 3, 16:35 UTCJul 3, 16:55 UTC20m
2026-07-02 N172LN - Jul 2, 17:55 UTCJul 2, 18:50 UTC55m
2026-07-02 N172LN - Jul 2, 14:10 UTCJul 2, 15:55 UTC1h 45m
2026-07-02 N172LN FXE → APF Jul 2, 11:35 UTCJul 2, 12:40 UTC1h 5m
2026-07-01 N172LN - Jul 1, 23:15 UTCJul 2, 00:55 UTC1h 40m
2026-07-01 N172LN - Jul 1, 20:35 UTCJul 1, 21:50 UTC1h 15m
2026-07-01 N172LN - Jul 1, 19:40 UTCJul 1, 20:00 UTC20m
2026-07-01 N172LN FXE → FXE Jul 1, 16:10 UTCJul 1, 16:25 UTC15m
2026-06-30 N172LN - Jun 30, 20:55 UTCJun 30, 23:05 UTC2h 10m
2026-06-30 N172LN - Jun 30, 15:45 UTCJun 30, 17:40 UTC1h 55m
2026-06-30 N172LN - Jun 30, 10:40 UTCJun 30, 13:05 UTC2h 25m
2026-06-30 N172LN PPM → FXE Jun 30, 02:30 UTCJun 30, 03:05 UTC35m
2026-06-30 N172LN - Jun 30, 01:00 UTCJun 30, 01:40 UTC41m
2026-06-30 N172LN - Jun 30, 00:04 UTCJun 30, 00:20 UTC15m
2026-06-29 N172LN - Jun 29, 22:55 UTCJun 29, 23:34 UTC40m
2026-06-29 N172LN - Jun 29, 22:00 UTCJun 29, 22:24 UTC25m
2026-06-29 N172LN - Jun 29, 18:44 UTCJun 29, 20:15 UTC1h 30m
2026-06-28 N172LN - Jun 28, 22:10 UTCJun 28, 22:49 UTC40m
2026-06-28 N172LN - Jun 28, 20:25 UTCJun 28, 21:14 UTC50m
2026-06-27 N172LN - Jun 27, 18:54 UTCJun 27, 20:04 UTC1h 10m
2026-06-27 N172LN - Jun 27, 16:20 UTCJun 27, 18:09 UTC1h 50m
2026-06-27 N172LN - Jun 27, 14:49 UTCJun 27, 15:34 UTC45m
2026-06-27 N172LN - Jun 27, 11:09 UTCJun 27, 13:09 UTC2h 0m
2026-06-27 N172LN - Jun 27, 00:14 UTCJun 27, 01:00 UTC45m
2026-06-26 N172LN - Jun 26, 18:44 UTCJun 26, 19:24 UTC40m
2026-06-24 N172LN - Jun 24, 16:45 UTCJun 24, 17:55 UTC1h 10m

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 N172LN page for operator, model, and routing details .

Mode-S A121A2 frequently asked

What is Mode-S code A121A2?
A121A2 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N172LN.
Where is Mode-S A121A2 registered?
Mode-S code A121A2 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 A121A2 broadcasting right now?
Yes. Mode-S A121A2 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A121A2, octal 50220642, decimal 10,559,906.
What flights does A121A2 operate?
Mode-S A121A2 has broadcast 1 distinct callsign, including N172LN.