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 10d ago
Flights observed
163
Distinct callsigns
1
Country
US
Last broadcast
10d 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 - 163 2026-07-25

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-25 CXK678 - Jul 25, 17:50 UTCJul 25, 19:50 UTC2h 0m
2026-07-24 CXK678 - Jul 24, 21:50 UTCJul 24, 22:50 UTC1h 0m
2026-07-24 CXK678 - Jul 24, 20:10 UTCJul 24, 21:30 UTC1h 20m
2026-07-23 CXK678 - Jul 23, 21:50 UTCJul 23, 22:50 UTC1h 0m
2026-07-23 CXK678 MYF → RAL Jul 23, 20:15 UTCJul 23, 21:30 UTC1h 15m
2026-07-23 CXK678 - Jul 23, 18:05 UTCJul 23, 19:10 UTC1h 5m
2026-07-23 CXK678 MYF → RAL Jul 23, 16:25 UTCJul 23, 17:45 UTC1h 20m
2026-07-22 CXK678 - Jul 22, 17:50 UTCJul 22, 19:35 UTC1h 45m
2026-07-21 CXK678 MYF → MYF Jul 21, 22:00 UTCJul 21, 23:05 UTC1h 5m
2026-07-21 CXK678 MYF → MYF Jul 21, 18:45 UTCJul 21, 19:15 UTC30m
2026-07-20 CXK678 - Jul 20, 17:05 UTCJul 20, 19:05 UTC2h 0m
2026-07-20 CXK678 - Jul 20, 00:10 UTCJul 20, 01:10 UTC1h 0m
2026-07-16 CXK678 - Jul 16, 17:10 UTCJul 16, 18:25 UTC1h 15m
2026-07-15 CXK678 - Jul 15, 22:45 UTCJul 16, 00:05 UTC1h 20m
2026-07-15 CXK678 - Jul 15, 19:40 UTCJul 15, 20:20 UTC40m
2026-07-14 CXK678 MYF → MYF Jul 14, 21:00 UTCJul 14, 21:35 UTC35m
2026-07-14 CXK678 - Jul 14, 16:25 UTCJul 14, 18:20 UTC1h 55m
2026-07-14 CXK678 - Jul 14, 03:15 UTCJul 14, 03:45 UTC30m
2026-07-14 CXK678 - Jul 14, 01:40 UTCJul 14, 02:15 UTC35m
2026-07-13 CXK678 - Jul 13, 18:30 UTCJul 13, 19:40 UTC1h 10m
2026-07-12 CXK678 RAL → MYF Jul 12, 23:15 UTCJul 13, 00:30 UTC1h 15m
2026-07-12 CXK678 MYF → RAL Jul 12, 22:05 UTCJul 12, 23:05 UTC1h 0m
2026-07-10 CXK678 RAL → MYF Jul 10, 16:00 UTCJul 10, 16:55 UTC55m
2026-07-09 CXK678 SBA → RAL Jul 9, 21:45 UTCJul 9, 22:55 UTC1h 10m
2026-07-09 CXK678 RAL → SBA Jul 9, 17:15 UTCJul 9, 18:55 UTC1h 40m
2026-07-07 CXK678 RAL → RAL Jul 7, 23:10 UTCJul 8, 00:05 UTC55m
2026-07-07 CXK678 RAL → RAL Jul 7, 02:10 UTCJul 7, 03:50 UTC1h 40m
2026-07-06 CXK678 - Jul 6, 03:25 UTCJul 6, 03:50 UTC25m
2026-07-06 CXK678 - Jul 6, 01:00 UTCJul 6, 02:50 UTC1h 50m
2026-07-05 CXK678 - Jul 5, 20:30 UTCJul 5, 23:40 UTC3h 10m
2026-07-03 CXK678 RAL → RAL Jul 3, 18:45 UTCJul 3, 21:25 UTC2h 40m
2026-07-03 CXK678 - Jul 3, 15:50 UTCJul 3, 16:45 UTC55m
2026-07-03 CXK678 - Jul 3, 14:10 UTCJul 3, 15:05 UTC55m
2026-06-28 CXK678 RAL → RAL Jun 28, 19:20 UTCJun 28, 20:14 UTC55m
2026-06-28 CXK678 RAL → RAL Jun 28, 17:30 UTCJun 28, 18:14 UTC45m
2026-06-28 CXK678 RAL → RAL Jun 28, 15:24 UTCJun 28, 16:09 UTC45m
2026-06-28 CXK678 - Jun 28, 01:15 UTCJun 28, 01:55 UTC40m
2026-06-27 CXK678 RAL → CLD Jun 27, 20:34 UTCJun 27, 21:44 UTC1h 10m
2026-06-26 CXK678 RAL → RAL Jun 26, 23:30 UTCJun 27, 01:35 UTC2h 5m
2026-06-26 CXK678 RAL → RAL Jun 26, 02:09 UTCJun 26, 04:10 UTC2h 0m
2026-06-25 CXK678 - Jun 25, 21:05 UTCJun 25, 22:45 UTC1h 40m
2026-06-25 CXK678 - Jun 25, 19:20 UTCJun 25, 19:49 UTC30m
2026-06-24 CXK678 RAL → RAL Jun 24, 19:34 UTCJun 24, 21:14 UTC1h 40m
2026-06-24 CXK678 RAL → RAL Jun 24, 15:44 UTCJun 24, 16:29 UTC45m
2026-06-24 CXK678 RAL → RAL Jun 24, 14:00 UTCJun 24, 14:50 UTC50m
2026-06-23 CXK678 RAL → RAL Jun 23, 22:55 UTCJun 24, 01:04 UTC2h 10m
2026-06-22 CXK678 RAL → RAL Jun 22, 23:05 UTCJun 23, 00:54 UTC1h 50m
2026-06-22 CXK678 RAL → RAL Jun 22, 20:55 UTCJun 22, 21:49 UTC55m
2026-06-22 CXK678 RAL → RAL Jun 22, 14:49 UTCJun 22, 15:45 UTC55m
2026-06-21 CXK678 RAL → RAL Jun 21, 21:29 UTCJun 21, 23:44 UTC2h 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 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 10d 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.