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sensors Mode-S transponder

402AC3

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-BOIO · CESSNA 152

Hex
402AC3
Octal
20025303
Decimal
4,205,251
Country
GB
Tail
G-BOIO
Type
C152
No current signal · last broadcast Jul 25, 15:15 UTC
Flights observed
56
Distinct callsigns
1
Country
GB
Last broadcast
Jul 25, 15:15 UTC

Last known position

Most recent position reported by Mode-S 402AC3.

Country allocation

The ICAO 24-bit address 402AC3 falls within the block assigned to United Kingdom (GB) by ICAO Annex 10, Volume III. Every aircraft registered in United Kingdom 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
GBOIO - 56 2026-07-25

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-25 GBOIO - Jul 25, 15:00 UTCJul 25, 15:15 UTC15m
2026-07-25 GBOIO - Jul 25, 13:20 UTCJul 25, 13:40 UTC20m
2026-07-25 GBOIO - Jul 25, 11:05 UTCJul 25, 11:50 UTC45m
2026-07-25 GBOIO - Jul 25, 08:45 UTCJul 25, 09:30 UTC45m
2026-07-22 GBOIO - Jul 22, 18:15 UTCJul 22, 19:00 UTC45m
2026-07-19 GBOIO - Jul 19, 14:30 UTCJul 19, 15:00 UTC30m
2026-07-17 GBOIO SEN → SEN Jul 17, 15:10 UTCJul 17, 15:55 UTC45m
2026-07-17 GBOIO - Jul 17, 13:25 UTCJul 17, 14:00 UTC35m
2026-07-12 GBOIO - Jul 12, 14:35 UTCJul 12, 15:30 UTC55m
2026-07-12 GBOIO - Jul 12, 08:40 UTCJul 12, 09:55 UTC1h 15m
2026-07-09 GBOIO OXF → SEN Jul 9, 10:50 UTCJul 9, 11:45 UTC55m
2026-07-06 GBOIO - Jul 6, 11:15 UTCJul 6, 12:00 UTC45m
2026-07-06 GBOIO SEN → OXF Jul 6, 07:55 UTCJul 6, 09:15 UTC1h 20m
2026-07-03 GBOIO - Jul 3, 15:25 UTCJul 3, 15:35 UTC10m
2026-06-27 GBOIO - Jun 27, 13:09 UTCJun 27, 13:35 UTC25m
2026-06-27 GBOIO - Jun 27, 10:25 UTCJun 27, 10:54 UTC30m
2026-06-27 GBOIO - Jun 27, 09:04 UTCJun 27, 09:40 UTC35m
2026-06-22 GBOIO - Jun 22, 17:15 UTCJun 22, 17:34 UTC20m
2026-06-22 GBOIO - Jun 22, 15:59 UTCJun 22, 16:24 UTC25m
2026-06-22 GBOIO - Jun 22, 11:50 UTCJun 22, 12:49 UTC1h 0m
2026-06-22 GBOIO - Jun 22, 08:00 UTCJun 22, 08:50 UTC50m
2026-06-21 GBOIO - Jun 21, 09:40 UTCJun 21, 10:09 UTC30m
2026-06-13 GBOIO - Jun 13, 11:00 UTCJun 13, 11:45 UTC45m
2026-06-13 GBOIO - Jun 13, 08:45 UTCJun 13, 09:20 UTC35m
2026-06-07 GBOIO - Jun 7, 13:05 UTCJun 7, 13:50 UTC45m
2026-06-07 GBOIO - Jun 7, 11:05 UTCJun 7, 11:50 UTC45m
2026-06-07 GBOIO - Jun 7, 09:15 UTCJun 7, 09:50 UTC35m
2026-05-31 GBOIO - May 31, 15:20 UTCMay 31, 16:05 UTC45m
2026-05-31 GBOIO SEN → SEN May 31, 11:15 UTCMay 31, 11:50 UTC35m
2026-05-31 GBOIO - May 31, 09:05 UTCMay 31, 09:40 UTC35m
2026-05-30 GBOIO - May 30, 11:20 UTCMay 30, 12:05 UTC45m
2026-05-30 GBOIO - May 30, 09:50 UTCMay 30, 10:10 UTC20m
2026-05-30 GBOIO - May 30, 08:50 UTCMay 30, 09:00 UTC10m
2026-05-27 GBOIO - May 27, 13:50 UTCMay 27, 14:45 UTC55m
2026-05-27 GBOIO - May 27, 11:15 UTCMay 27, 12:10 UTC55m
2026-05-22 GBOIO - May 22, 14:30 UTCMay 22, 15:05 UTC35m
2026-05-17 GBOIO - May 17, 12:01 UTCMay 17, 12:10 UTC10m
2026-05-17 GBOIO - May 17, 11:15 UTCMay 17, 11:30 UTC15m
2026-05-16 GBOIO SEN → SEN May 16, 11:25 UTCMay 16, 12:11 UTC45m
2026-05-16 GBOIO SEN → SEN May 16, 08:55 UTCMay 16, 09:51 UTC55m
2026-05-15 GBOIO - May 15, 15:30 UTCMay 15, 16:15 UTC45m
2026-05-10 GBOIO - May 10, 14:14 UTCMay 10, 14:49 UTC35m
2026-05-09 GBOIO - May 9, 12:10 UTCMay 9, 12:50 UTC40m
2026-05-09 GBOIO - May 9, 10:35 UTCMay 9, 11:00 UTC25m
2026-05-09 GBOIO - May 9, 09:15 UTCMay 9, 09:45 UTC30m
2026-05-08 GBOIO - May 8, 15:45 UTCMay 8, 16:25 UTC40m
2026-05-05 GBOIO SEN → SEN May 5, 17:05 UTCMay 5, 18:10 UTC1h 5m
2026-05-05 GBOIO - May 5, 12:00 UTCMay 5, 12:30 UTC30m
2026-05-05 GBOIO - May 5, 10:30 UTCMay 5, 11:15 UTC45m
2026-05-03 GBOIO - May 3, 11:10 UTCMay 3, 12:00 UTC50m

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 G-BOIO page for operator, model, and routing details .

Mode-S 402AC3 frequently asked

What is Mode-S code 402AC3?
402AC3 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-BOIO.
Where is Mode-S 402AC3 registered?
Mode-S code 402AC3 is allocated to United Kingdom (GB). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 402AC3 broadcasting right now?
No active broadcast right now. Last signal was Jul 25, 15:15 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 402AC3, octal 20025303, decimal 4,205,251.
What flights does 402AC3 operate?
Mode-S 402AC3 has broadcast 1 distinct callsign, including GBOIO.