Apparatus

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sensors Mode-S transponder

AB4B51

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N827ES · operated by ATP AIRCRAFT 1 LLC

Hex
AB4B51
Octal
52645521
Decimal
11,225,937
Country
US
Tail
N827ES
Type
C172
No current signal · last broadcast 10h ago
Flights observed
111
Distinct callsigns
1
Country
US
Last broadcast
10h ago

Last known position

Most recent position reported by Mode-S AB4B51.

Country allocation

The ICAO 24-bit address AB4B51 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
CXK678 - 111 2026-06-20

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-06-20 CXK678 RAL → RAL Jun 20, 16:49 UTCJun 20, 17:14 UTC25m
2026-06-19 CXK678 RAL → RAL Jun 19, 22:14 UTCJun 20, 00:24 UTC2h 10m
2026-06-19 CXK678 RAL → RAL Jun 19, 17:44 UTCJun 19, 20:14 UTC2h 30m
2026-06-19 CXK678 LGB → RAL Jun 19, 00:00 UTCJun 19, 00:34 UTC34m
2026-06-18 CXK678 - Jun 18, 20:00 UTCJun 18, 21:40 UTC1h 40m
2026-06-18 CXK678 - Jun 18, 17:30 UTCJun 18, 18:15 UTC45m
2026-06-17 CXK678 - Jun 17, 16:05 UTCJun 17, 17:40 UTC1h 35m
2026-06-16 CXK678 - Jun 16, 23:15 UTCJun 17, 00:10 UTC55m
2026-06-16 CXK678 - Jun 16, 20:10 UTCJun 16, 21:00 UTC50m
2026-06-16 CXK678 - Jun 16, 17:00 UTCJun 16, 17:59 UTC1h 0m
2026-06-16 CXK678 - Jun 16, 04:20 UTCJun 16, 05:25 UTC1h 5m
2026-06-15 CXK678 - Jun 15, 22:30 UTCJun 15, 23:50 UTC1h 20m
2026-06-15 CXK678 - Jun 15, 20:40 UTCJun 15, 21:14 UTC35m
2026-06-15 CXK678 - Jun 15, 18:55 UTCJun 15, 19:20 UTC25m
2026-06-14 CXK678 - Jun 14, 20:10 UTCJun 14, 22:00 UTC1h 50m
2026-06-14 CXK678 LGB → LGB Jun 14, 04:05 UTCJun 14, 04:35 UTC30m
2026-06-13 CXK678 - Jun 13, 21:25 UTCJun 13, 23:05 UTC1h 40m
2026-06-12 CXK678 LGB → LGB Jun 12, 23:45 UTCJun 13, 00:40 UTC55m
2026-06-12 CXK678 - Jun 12, 20:45 UTCJun 12, 21:55 UTC1h 10m
2026-06-12 CXK678 - Jun 12, 18:40 UTCJun 12, 19:20 UTC40m
2026-06-12 CXK678 - Jun 12, 14:15 UTCJun 12, 15:40 UTC1h 25m
2026-06-12 CXK678 - Jun 12, 02:20 UTCJun 12, 04:55 UTC2h 35m
2026-06-11 CXK678 - Jun 11, 23:05 UTCJun 12, 00:30 UTC1h 25m
2026-06-11 CXK678 - Jun 11, 20:15 UTCJun 11, 21:30 UTC1h 15m
2026-06-11 CXK678 - Jun 11, 18:45 UTCJun 11, 19:00 UTC15m
2026-06-10 CXK678 - Jun 10, 23:15 UTCJun 10, 23:45 UTC30m
2026-06-10 CXK678 RAL → RAL Jun 10, 21:35 UTCJun 10, 22:20 UTC45m
2026-06-09 CXK678 RAL → RAL Jun 9, 18:30 UTCJun 9, 20:55 UTC2h 25m
2026-06-09 CXK678 SBA → RAL Jun 9, 05:20 UTCJun 9, 06:40 UTC1h 20m
2026-06-08 CXK678 RAL → SBA Jun 8, 23:45 UTCJun 9, 01:25 UTC1h 40m
2026-06-06 CXK678 - Jun 6, 19:10 UTCJun 6, 19:34 UTC25m
2026-06-05 CXK678 - Jun 5, 20:40 UTCJun 5, 21:10 UTC30m
2026-06-05 CXK678 - Jun 5, 18:05 UTCJun 5, 19:10 UTC1h 5m
2026-06-04 CXK678 - Jun 4, 23:30 UTCJun 5, 00:40 UTC1h 10m
2026-06-04 CXK678 - Jun 4, 18:35 UTCJun 4, 19:35 UTC1h 0m
2026-06-04 CXK678 BFL → POC Jun 4, 03:55 UTCJun 4, 05:45 UTC1h 50m
2026-06-04 CXK678 - Jun 4, 01:20 UTCJun 4, 02:30 UTC1h 10m
2026-06-03 CXK678 - Jun 3, 21:20 UTCJun 3, 23:10 UTC1h 50m
2026-06-03 CXK678 - Jun 3, 18:45 UTCJun 3, 19:35 UTC50m
2026-06-03 CXK678 - Jun 3, 01:15 UTCJun 3, 02:15 UTC1h 0m
2026-06-02 CXK678 - Jun 2, 21:45 UTCJun 2, 23:45 UTC2h 0m
2026-06-02 CXK678 - Jun 2, 19:15 UTCJun 2, 19:55 UTC40m
2026-06-01 CXK678 - Jun 1, 20:45 UTCJun 1, 22:45 UTC2h 0m
2026-06-01 CXK678 - Jun 1, 18:25 UTCJun 1, 19:15 UTC50m
2026-06-01 CXK678 VIS → POC Jun 1, 04:30 UTCJun 1, 06:05 UTC1h 35m
2026-06-01 CXK678 - Jun 1, 00:35 UTCJun 1, 02:05 UTC1h 30m
2026-05-31 CXK678 - May 31, 21:15 UTCMay 31, 22:25 UTC1h 10m
2026-05-31 CXK678 POC → POC May 31, 19:00 UTCMay 31, 19:45 UTC45m
2026-05-31 CXK678 - May 31, 16:15 UTCMay 31, 16:55 UTC40m
2026-05-31 CXK678 - May 31, 13:55 UTCMay 31, 14:55 UTC1h 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 N827ES page for operator, model, and routing details .

Mode-S AB4B51 frequently asked

What is Mode-S code AB4B51?
AB4B51 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N827ES.
Where is Mode-S AB4B51 registered?
Mode-S code AB4B51 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 AB4B51 broadcasting right now?
No active broadcast right now. Last signal was 10h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AB4B51, octal 52645521, decimal 11,225,937.
What flights does AB4B51 operate?
Mode-S AB4B51 has broadcast 1 distinct callsign, including CXK678.