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sensors Mode-S transponder

AB9123

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8440X · CESSNA 172 Skyhawk · operated by HANCOCK GREGORY C, MENOZZI ELIZABETH M

Hex
AB9123
Octal
52710443
Decimal
11,243,811
Country
US
Tail
N8440X
Type
C172
No current signal · last broadcast 3d ago
Flights observed
69
Distinct callsigns
1
Country
US
Last broadcast
3d ago

Last known position

Most recent position reported by Mode-S AB9123.

Country allocation

The ICAO 24-bit address AB9123 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
N8440X - 69 2026-07-11

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-11 N8440X BFI → ESD Jul 11, 14:55 UTCJul 11, 16:00 UTC1h 5m
2026-07-11 N8440X - Jul 11, 13:35 UTCJul 11, 14:30 UTC55m
2026-07-09 N8440X - Jul 9, 20:45 UTCJul 9, 21:45 UTC1h 0m
2026-07-09 N8440X - Jul 9, 19:25 UTCJul 9, 19:45 UTC20m
2026-07-07 N8440X - Jul 7, 17:35 UTCJul 7, 18:10 UTC35m
2026-07-07 N8440X ESD → PAE Jul 7, 00:55 UTCJul 7, 01:35 UTC40m
2026-07-02 N8440X - Jul 2, 21:30 UTCJul 2, 23:10 UTC1h 40m
2026-07-02 N8440X - Jul 2, 16:45 UTCJul 2, 18:20 UTC1h 35m
2026-07-02 N8440X - Jul 2, 12:15 UTCJul 2, 12:30 UTC15m
2026-06-30 N8440X - Jun 30, 21:35 UTCJun 30, 22:35 UTC1h 0m
2026-06-30 N8440X - Jun 30, 19:40 UTCJun 30, 20:50 UTC1h 10m
2026-06-30 N8440X - Jun 30, 15:00 UTCJun 30, 17:15 UTC2h 15m
2026-06-29 N8440X - Jun 29, 12:34 UTCJun 29, 14:04 UTC1h 30m
2026-06-25 N8440X - Jun 25, 15:10 UTCJun 25, 17:09 UTC2h 0m
2026-06-25 N8440X - Jun 25, 12:30 UTCJun 25, 14:29 UTC2h 0m
2026-06-24 N8440X - Jun 24, 22:55 UTCJun 25, 00:55 UTC2h 0m
2026-06-24 N8440X - Jun 24, 10:49 UTCJun 24, 13:40 UTC2h 50m
2026-06-23 N8440X - Jun 23, 21:54 UTCJun 23, 23:44 UTC1h 50m
2026-06-23 N8440X - Jun 23, 17:34 UTCJun 23, 19:34 UTC2h 0m
2026-06-23 N8440X - Jun 23, 13:24 UTCJun 23, 15:59 UTC2h 35m
2026-06-20 N8440X - Jun 20, 12:54 UTCJun 20, 13:44 UTC50m
2026-06-19 N8440X - Jun 19, 22:24 UTCJun 20, 00:34 UTC2h 10m
2026-06-18 N8440X - Jun 18, 14:01 UTCJun 18, 16:40 UTC2h 40m
2026-06-17 N8440X - Jun 17, 01:05 UTCJun 17, 01:30 UTC25m
2026-06-16 N8440X - Jun 16, 22:50 UTCJun 16, 23:50 UTC1h 0m
2026-06-16 N8440X - Jun 16, 19:15 UTCJun 16, 19:19 UTC5m
2026-06-16 N8440X - Jun 16, 18:15 UTCJun 16, 18:25 UTC10m
2026-06-16 N8440X - Jun 16, 15:15 UTCJun 16, 15:30 UTC15m
2026-06-15 N8440X - Jun 15, 19:30 UTCJun 15, 19:39 UTC10m
2026-06-15 N8440X - Jun 15, 13:45 UTCJun 15, 14:34 UTC50m
2026-06-15 N8440X - Jun 15, 03:45 UTCJun 15, 04:15 UTC30m
2026-06-15 N8440X - Jun 15, 01:45 UTCJun 15, 02:30 UTC45m
2026-06-14 N8440X ESD → PAE Jun 14, 22:10 UTCJun 14, 23:20 UTC1h 10m
2026-06-13 N8440X - Jun 13, 20:15 UTCJun 13, 20:35 UTC20m
2026-06-13 N8440X - Jun 13, 18:55 UTCJun 13, 19:10 UTC15m
2026-06-13 N8440X ESD → ESD Jun 13, 17:40 UTCJun 13, 18:00 UTC20m
2026-06-11 N8440X BLI → ESD Jun 11, 18:40 UTCJun 11, 18:55 UTC15m
2026-06-09 N8440X - Jun 9, 17:45 UTCJun 9, 18:35 UTC50m
2026-06-09 N8440X - Jun 9, 00:40 UTCJun 9, 01:25 UTC45m
2026-06-08 N8440X - Jun 8, 23:40 UTCJun 8, 23:55 UTC15m
2026-06-08 N8440X - Jun 8, 22:55 UTCJun 8, 23:10 UTC15m
2026-06-08 N8440X ESD → FRD Jun 8, 20:05 UTCJun 8, 21:45 UTC1h 40m
2026-06-08 N8440X - Jun 8, 19:20 UTCJun 8, 19:35 UTC15m
2026-06-08 N8440X - Jun 8, 17:30 UTCJun 8, 17:45 UTC15m
2026-05-29 N8440X - May 29, 20:20 UTCMay 29, 21:35 UTC1h 15m
2026-05-28 N8440X - May 28, 22:25 UTCMay 28, 23:05 UTC40m
2026-05-28 N8440X - May 28, 20:20 UTCMay 28, 21:40 UTC1h 20m
2026-05-27 N8440X FBS → ESD May 27, 20:25 UTCMay 27, 20:35 UTC10m
2026-05-27 N8440X ESD → FRD May 27, 18:15 UTCMay 27, 18:30 UTC15m
2026-05-25 N8440X - May 25, 20:04 UTCMay 25, 21:24 UTC1h 20m

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 N8440X page for operator, model, and routing details .

Mode-S AB9123 frequently asked

What is Mode-S code AB9123?
AB9123 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8440X.
Where is Mode-S AB9123 registered?
Mode-S code AB9123 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 AB9123 broadcasting right now?
No active broadcast right now. Last signal was 3d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AB9123, octal 52710443, decimal 11,243,811.
What flights does AB9123 operate?
Mode-S AB9123 has broadcast 1 distinct callsign, including N8440X.