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sensors Mode-S transponder

AB2AC1

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N81891 · PIPER PA-28-140/150/160/180 · operated by GARNET AVIATION LLC

Hex
AB2AC1
Octal
52625301
Decimal
11,217,601
Country
US
Tail
N81891
Type
P28A
No current signal · last broadcast 2h ago
Flights observed
158
Distinct callsigns
1
Country
US
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S AB2AC1.

Country allocation

The ICAO 24-bit address AB2AC1 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
N81891 - 158 2026-07-19

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-19 N81891 - Jul 19, 20:30 UTCJul 19, 21:10 UTC40m
2026-07-19 N81891 - Jul 19, 12:35 UTCJul 19, 13:15 UTC40m
2026-07-18 N81891 - Jul 18, 20:25 UTCJul 18, 21:50 UTC1h 25m
2026-07-18 N81891 - Jul 18, 18:30 UTCJul 18, 19:25 UTC55m
2026-07-17 N81891 - Jul 17, 18:44 UTCJul 17, 20:00 UTC1h 15m
2026-07-17 N81891 - Jul 17, 15:25 UTCJul 17, 16:49 UTC1h 25m
2026-07-16 N81891 - Jul 16, 18:40 UTCJul 16, 19:40 UTC1h 0m
2026-07-13 N81891 - Jul 13, 16:40 UTCJul 13, 17:45 UTC1h 5m
2026-07-13 N81891 - Jul 13, 14:25 UTCJul 13, 15:35 UTC1h 10m
2026-07-12 N81891 - Jul 12, 17:01 UTCJul 12, 17:45 UTC45m
2026-07-11 N81891 - Jul 11, 15:05 UTCJul 11, 15:30 UTC25m
2026-07-10 N81891 - Jul 10, 21:05 UTCJul 10, 21:25 UTC20m
2026-07-10 N81891 - Jul 10, 20:20 UTCJul 10, 20:30 UTC10m
2026-07-10 N81891 - Jul 10, 19:05 UTCJul 10, 19:25 UTC20m
2026-07-10 N81891 - Jul 10, 16:35 UTCJul 10, 17:40 UTC1h 5m
2026-07-10 N81891 - Jul 10, 14:25 UTCJul 10, 15:35 UTC1h 10m
2026-07-09 N81891 - Jul 9, 20:25 UTCJul 9, 21:15 UTC50m
2026-07-09 N81891 - Jul 9, 18:35 UTCJul 9, 19:40 UTC1h 5m
2026-07-09 N81891 - Jul 9, 14:45 UTCJul 9, 15:35 UTC50m
2026-07-09 N81891 - Jul 9, 00:25 UTCJul 9, 00:45 UTC20m
2026-07-08 N81891 - Jul 8, 22:40 UTCJul 8, 23:35 UTC55m
2026-07-07 N81891 - Jul 7, 22:35 UTCJul 7, 23:35 UTC1h 0m
2026-07-07 N81891 - Jul 7, 20:00 UTCJul 7, 21:25 UTC1h 25m
2026-07-07 N81891 - Jul 7, 18:45 UTCJul 7, 19:30 UTC45m
2026-07-07 N81891 - Jul 7, 16:25 UTCJul 7, 17:15 UTC50m
2026-07-03 N81891 - Jul 3, 20:50 UTCJul 3, 21:50 UTC1h 0m
2026-07-03 N81891 - Jul 3, 18:45 UTCJul 3, 20:00 UTC1h 15m
2026-07-02 N81891 - Jul 2, 19:00 UTCJul 2, 21:05 UTC2h 5m
2026-07-02 N81891 - Jul 2, 17:05 UTCJul 2, 17:55 UTC50m
2026-07-02 N81891 - Jul 2, 02:45 UTCJul 2, 04:00 UTC1h 15m
2026-06-30 N81891 - Jun 30, 22:50 UTCJul 1, 00:05 UTC1h 15m
2026-06-30 N81891 - Jun 30, 20:50 UTCJun 30, 21:45 UTC55m
2026-06-30 N81891 - Jun 30, 16:55 UTCJun 30, 17:40 UTC45m
2026-06-29 N81891 - Jun 29, 14:39 UTCJun 29, 15:45 UTC1h 5m
2026-06-26 N81891 - Jun 26, 16:35 UTCJun 26, 17:44 UTC1h 10m
2026-06-25 N81891 - Jun 25, 20:45 UTCJun 25, 21:35 UTC50m
2026-06-25 N81891 - Jun 25, 18:29 UTCJun 25, 19:49 UTC1h 20m
2026-06-25 N81891 - Jun 25, 16:45 UTCJun 25, 17:44 UTC1h 0m
2026-06-25 N81891 - Jun 25, 03:34 UTCJun 25, 03:59 UTC25m
2026-06-24 N81891 - Jun 24, 19:29 UTCJun 24, 20:24 UTC55m
2026-06-24 N81891 - Jun 24, 16:59 UTCJun 24, 17:45 UTC45m
2026-06-24 N81891 - Jun 24, 14:55 UTCJun 24, 15:54 UTC1h 0m
2026-06-24 N81891 - Jun 24, 03:10 UTCJun 24, 04:15 UTC1h 5m
2026-06-23 N81891 - Jun 23, 22:55 UTCJun 23, 23:44 UTC50m
2026-06-23 N81891 - Jun 23, 21:39 UTCJun 23, 21:49 UTC10m
2026-06-23 N81891 - Jun 23, 18:39 UTCJun 23, 19:39 UTC1h 0m
2026-06-23 N81891 - Jun 23, 16:39 UTCJun 23, 17:34 UTC55m
2026-06-22 N81891 - Jun 22, 20:19 UTCJun 22, 21:40 UTC1h 20m
2026-06-22 N81891 - Jun 22, 16:45 UTCJun 22, 17:50 UTC1h 5m
2026-06-21 N81891 - Jun 21, 19:24 UTCJun 21, 20:40 UTC1h 15m

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 N81891 page for operator, model, and routing details .

Mode-S AB2AC1 frequently asked

What is Mode-S code AB2AC1?
AB2AC1 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N81891.
Where is Mode-S AB2AC1 registered?
Mode-S code AB2AC1 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 AB2AC1 broadcasting right now?
No active broadcast right now. Last signal was 2h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AB2AC1, octal 52625301, decimal 11,217,601.
What flights does AB2AC1 operate?
Mode-S AB2AC1 has broadcast 1 distinct callsign, including N81891.