Apparatus

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sensors Mode-S transponder

A121C0

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N172MT · CESSNA 172 Skyhawk · operated by TREDE 2020 C172 LLC

Hex
A121C0
Octal
50220700
Decimal
10,559,936
Country
US
Tail
N172MT
Type
C172
Broadcasting now · callsign N172MT · 5,600 ft
Flights observed
137
Distinct callsigns
1
Country
US
Last broadcast
Jul 26, 17:45 UTC

Current position

A121C0 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A121C0 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
N172MT - 137 2026-07-26

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 N172MT APA → APA Jul 26, 17:00 UTCJul 26, 17:45 UTC45m
2026-07-26 N172MT - Jul 26, 13:15 UTCJul 26, 14:35 UTC1h 20m
2026-07-25 N172MT - Jul 25, 16:50 UTCJul 25, 17:40 UTC50m
2026-07-25 N172MT - Jul 25, 15:05 UTCJul 25, 15:35 UTC30m
2026-07-25 N172MT APA → APA Jul 25, 11:50 UTCJul 25, 12:50 UTC1h 0m
2026-07-23 N172MT - Jul 23, 15:40 UTCJul 23, 16:50 UTC1h 10m
2026-07-23 N172MT - Jul 23, 10:50 UTCJul 23, 14:25 UTC3h 35m
2026-07-22 N172MT - Jul 22, 12:55 UTCJul 22, 13:45 UTC50m
2026-07-21 N172MT - Jul 21, 15:55 UTCJul 21, 16:35 UTC40m
2026-07-20 N172MT - Jul 20, 18:50 UTCJul 20, 19:05 UTC15m
2026-07-20 N172MT - Jul 20, 17:05 UTCJul 20, 17:30 UTC25m
2026-07-20 N172MT COS → APA Jul 20, 14:05 UTCJul 20, 14:55 UTC50m
2026-07-20 N172MT - Jul 20, 13:00 UTCJul 20, 14:00 UTC1h 0m
2026-07-19 N172MT APA → APA Jul 19, 13:45 UTCJul 19, 15:25 UTC1h 40m
2026-07-18 N172MT - Jul 18, 18:25 UTCJul 18, 18:55 UTC30m
2026-07-18 N172MT APA → APA Jul 18, 15:30 UTCJul 18, 16:35 UTC1h 5m
2026-07-18 N172MT APA → APA Jul 18, 11:15 UTCJul 18, 11:50 UTC35m
2026-07-17 N172MT - Jul 17, 16:59 UTCJul 17, 17:40 UTC40m
2026-07-17 N172MT APA → APA Jul 17, 13:40 UTCJul 17, 15:00 UTC1h 20m
2026-07-16 N172MT - Jul 16, 18:25 UTCJul 16, 19:14 UTC50m
2026-07-16 N172MT - Jul 16, 16:05 UTCJul 16, 17:20 UTC1h 15m
2026-07-16 N172MT - Jul 16, 12:34 UTCJul 16, 13:49 UTC1h 15m
2026-07-15 N172MT - Jul 15, 17:15 UTCJul 15, 17:35 UTC20m
2026-07-15 N172MT - Jul 15, 16:00 UTCJul 15, 16:30 UTC30m
2026-07-14 N172MT - Jul 14, 20:00 UTCJul 14, 20:35 UTC35m
2026-07-14 N172MT - Jul 14, 16:50 UTCJul 14, 18:30 UTC1h 40m
2026-07-14 N172MT APA → APA Jul 14, 13:00 UTCJul 14, 14:25 UTC1h 25m
2026-07-11 N172MT - Jul 11, 12:55 UTCJul 11, 13:50 UTC55m
2026-07-10 N172MT - Jul 10, 12:55 UTCJul 10, 14:25 UTC1h 30m
2026-07-09 N172MT APA → APA Jul 9, 16:50 UTCJul 9, 18:30 UTC1h 40m
2026-07-09 N172MT - Jul 9, 13:35 UTCJul 9, 14:40 UTC1h 5m
2026-07-06 N172MT APA → APA Jul 6, 12:50 UTCJul 6, 14:20 UTC1h 30m
2026-07-05 N172MT - Jul 5, 19:30 UTCJul 5, 20:30 UTC1h 0m
2026-07-05 N172MT - Jul 5, 14:30 UTCJul 5, 15:40 UTC1h 10m
2026-07-03 N172MT - Jul 3, 05:35 UTCJul 3, 06:45 UTC1h 10m
2026-07-03 N172MT - Jul 3, 01:45 UTCJul 3, 03:05 UTC1h 20m
2026-07-02 N172MT - Jul 2, 18:25 UTCJul 2, 19:25 UTC1h 0m
2026-07-02 N172MT - Jul 2, 14:55 UTCJul 2, 16:45 UTC1h 50m
2026-06-30 N172MT APA → APA Jun 30, 16:00 UTCJun 30, 17:30 UTC1h 30m
2026-06-30 N172MT - Jun 30, 12:55 UTCJun 30, 13:35 UTC40m
2026-06-30 N172MT - Jun 30, 11:50 UTCJun 30, 12:20 UTC30m
2026-06-29 N172MT - Jun 29, 16:00 UTCJun 29, 17:14 UTC1h 15m
2026-06-29 N172MT - Jun 29, 12:45 UTCJun 29, 14:14 UTC1h 30m
2026-06-28 N172MT - Jun 28, 14:50 UTCJun 28, 16:00 UTC1h 10m
2026-06-27 N172MT APA → APA Jun 27, 10:50 UTCJun 27, 11:14 UTC25m
2026-06-26 N172MT - Jun 26, 15:05 UTCJun 26, 16:49 UTC1h 45m
2026-06-24 N172MT - Jun 24, 17:55 UTCJun 24, 19:10 UTC1h 15m
2026-06-24 N172MT - Jun 24, 16:05 UTCJun 24, 17:14 UTC1h 10m
2026-06-22 N172MT - Jun 22, 13:54 UTCJun 22, 14:45 UTC50m
2026-06-21 N172MT APA → APA Jun 21, 17:05 UTCJun 21, 17:39 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 N172MT page for operator, model, and routing details .

Mode-S A121C0 frequently asked

What is Mode-S code A121C0?
A121C0 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N172MT.
Where is Mode-S A121C0 registered?
Mode-S code A121C0 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 A121C0 broadcasting right now?
Yes. Mode-S A121C0 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A121C0, octal 50220700, decimal 10,559,936.
What flights does A121C0 operate?
Mode-S A121C0 has broadcast 1 distinct callsign, including N172MT.