sensors Mode-S transponder

A21557

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N233TJ · CESSNA 525B Citation CJ3 · operated by CORSAIR TWO LLC

Hex
A21557
Octal
50412527
Decimal
10,622,295
Country
US
Tail
N233TJ
Type
C25B
No current signal · last broadcast 1d ago
Flights observed
54
Distinct callsigns
2
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A21557.

Country allocation

The ICAO 24-bit address A21557 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 2 distinct

Callsign Airline Flights Last seen
N233TJ - 47 2026-05-15
LN233TJ - 7 2026-06-01

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-06-01 LN233TJ SKA → BFI Jun 1, 08:15 UTCJun 1, 08:55 UTC40m
2026-06-01 LN233TJ BFI → GEG Jun 1, 00:40 UTCJun 1, 01:20 UTC40m
2026-05-25 LN233TJ COE → BFI May 25, 03:50 UTCMay 25, 04:40 UTC50m
2026-05-24 LN233TJ - May 24, 18:10 UTCMay 24, 18:50 UTC40m
2026-05-19 LN233TJ - May 19, 02:20 UTCMay 19, 03:00 UTC40m
2026-05-18 LN233TJ - May 18, 19:25 UTCMay 18, 19:55 UTC30m
2026-05-16 LN233TJ - May 16, 02:20 UTCMay 16, 06:01 UTC3h 41m
2026-05-15 N233TJ - May 15, 05:40 UTCMay 15, 09:30 UTC3h 50m
2026-05-13 N233TJ - May 13, 23:20 UTCMay 14, 00:25 UTC1h 5m
2026-05-13 N233TJ - May 13, 14:35 UTCMay 13, 15:25 UTC50m
2026-05-13 N233TJ - May 13, 06:15 UTCMay 13, 07:00 UTC45m
2026-05-12 N233TJ BFI → SFF May 12, 19:05 UTCMay 12, 19:50 UTC45m
2026-05-12 N233TJ - May 12, 03:30 UTCMay 12, 04:05 UTC35m
2026-05-11 N233TJ - May 11, 18:55 UTCMay 11, 19:35 UTC40m
2026-05-09 N233TJ - May 9, 21:14 UTCMay 9, 22:30 UTC1h 15m
2026-05-09 N233TJ - May 9, 20:34 UTCMay 9, 20:44 UTC10m
2026-05-09 N233TJ - May 9, 13:25 UTCMay 9, 15:00 UTC1h 35m
2026-05-07 N233TJ ANC → BFI May 7, 10:50 UTCMay 7, 13:50 UTC3h 0m
2026-05-06 N233TJ - May 6, 16:20 UTCMay 6, 20:00 UTC3h 40m
2026-05-04 N233TJ - May 4, 16:10 UTCMay 5, 01:50 UTC9h 41m
2026-05-03 N233TJ ANC → BFI May 3, 12:50 UTCMay 3, 16:05 UTC3h 15m
2026-05-02 N233TJ - May 2, 14:00 UTCMay 2, 17:50 UTC3h 50m
2026-05-02 N233TJ ANC → BFI May 2, 07:40 UTCMay 2, 11:00 UTC3h 20m
2026-05-01 N233TJ - May 1, 16:30 UTCMay 1, 20:10 UTC3h 40m
2026-04-29 N233TJ - Apr 29, 03:10 UTCApr 29, 05:00 UTC1h 50m
2026-04-28 N233TJ - Apr 28, 18:15 UTCApr 28, 19:45 UTC1h 30m
2026-04-28 N233TJ - Apr 28, 02:25 UTCApr 28, 03:00 UTC35m
2026-04-27 N233TJ - Apr 27, 21:15 UTCApr 27, 21:50 UTC35m
2026-04-24 N233TJ - Apr 24, 05:05 UTCApr 24, 05:40 UTC35m
2026-04-23 N233TJ - Apr 23, 21:30 UTCApr 23, 21:55 UTC25m
2026-04-23 N233TJ - Apr 23, 03:35 UTCApr 23, 04:20 UTC45m
2026-04-22 N233TJ - Apr 22, 22:45 UTCApr 22, 23:25 UTC40m
2026-04-22 N233TJ HIO → BFI Apr 22, 18:35 UTCApr 22, 19:05 UTC30m
2026-04-22 N233TJ HIO → HIO Apr 22, 15:00 UTCApr 22, 15:15 UTC15m
2026-04-22 N233TJ HIO → HIO Apr 22, 14:10 UTCApr 22, 14:55 UTC45m
2026-04-22 N233TJ HIO → HIO Apr 22, 01:50 UTCApr 22, 02:15 UTC25m
2026-04-21 N233TJ HIO → HIO Apr 21, 20:35 UTCApr 21, 20:40 UTC5m
2026-04-21 N233TJ HIO → HIO Apr 21, 19:15 UTCApr 21, 19:25 UTC10m
2026-04-21 N233TJ HIO → HIO Apr 21, 17:50 UTCApr 21, 18:10 UTC20m
2026-04-21 N233TJ BFI → HIO Apr 21, 13:20 UTCApr 21, 13:50 UTC30m
2026-04-21 N233TJ - Apr 21, 01:45 UTCApr 21, 02:30 UTC45m
2026-04-20 N233TJ BFI → GEG Apr 20, 15:20 UTCApr 21, 01:35 UTC10h 15m
2026-04-19 N233TJ - Apr 19, 02:00 UTCApr 19, 03:40 UTC1h 40m
2026-04-18 N233TJ - Apr 18, 19:20 UTCApr 18, 20:55 UTC1h 35m
2026-04-17 N233TJ - Apr 17, 13:20 UTCApr 17, 13:30 UTC10m
2026-04-17 N233TJ - Apr 17, 11:20 UTCApr 17, 13:15 UTC1h 55m
2026-04-17 N233TJ - Apr 17, 10:20 UTCApr 17, 11:15 UTC55m
2026-04-17 N233TJ - Apr 17, 09:20 UTCApr 17, 09:40 UTC20m
2026-04-17 N233TJ - Apr 17, 07:40 UTCApr 17, 09:15 UTC1h 35m
2026-04-17 N233TJ - Apr 17, 05:55 UTCApr 17, 07:05 UTC1h 10m

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 N233TJ page for operator, model, and routing details .

Mode-S A21557 frequently asked

What is Mode-S code A21557?
A21557 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N233TJ.
Where is Mode-S A21557 registered?
Mode-S code A21557 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 A21557 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A21557, octal 50412527, decimal 10,622,295.
What flights does A21557 operate?
Mode-S A21557 has broadcast 2 distinct callsigns, including N233TJ, LN233TJ.