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sensors Mode-S transponder

401855

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-AXSW · CESSNA 150

Hex
401855
Octal
20014125
Decimal
4,200,533
Country
GB
Tail
G-AXSW
Type
C150
No current signal · last broadcast 7h ago
Flights observed
116
Distinct callsigns
1
Country
GB
Last broadcast
7h ago

Last known position

Most recent position reported by Mode-S 401855.

Country allocation

The ICAO 24-bit address 401855 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
GAXSW - 116 2026-07-21

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-21 GAXSW BLK → BLK Jul 21, 14:25 UTCJul 21, 15:15 UTC50m
2026-07-21 GAXSW BLK → BLK Jul 21, 13:20 UTCJul 21, 13:50 UTC30m
2026-07-21 GAXSW BLK → BLK Jul 21, 09:05 UTCJul 21, 09:55 UTC50m
2026-07-20 GAXSW - Jul 20, 10:50 UTCJul 20, 11:30 UTC40m
2026-07-18 GAXSW BLK → BLK Jul 18, 14:10 UTCJul 18, 15:40 UTC1h 30m
2026-07-18 GAXSW BLK → BLK Jul 18, 12:15 UTCJul 18, 13:10 UTC55m
2026-07-18 GAXSW BLK → BLK Jul 18, 09:05 UTCJul 18, 11:20 UTC2h 15m
2026-07-17 GAXSW BLK → BLK Jul 17, 15:29 UTCJul 17, 16:34 UTC1h 5m
2026-07-17 GAXSW BLK → BLK Jul 17, 12:25 UTCJul 17, 14:44 UTC2h 20m
2026-07-17 GAXSW BLK → BLK Jul 17, 08:59 UTCJul 17, 11:50 UTC2h 50m
2026-07-16 GAXSW BLK → BLK Jul 16, 15:19 UTCJul 16, 16:15 UTC55m
2026-07-16 GAXSW BLK → BLK Jul 16, 12:25 UTCJul 16, 13:34 UTC1h 10m
2026-07-16 GAXSW - Jul 16, 10:50 UTCJul 16, 11:34 UTC45m
2026-07-16 GAXSW BLK → BLK Jul 16, 08:40 UTCJul 16, 09:55 UTC1h 15m
2026-07-15 GAXSW BLK → BLK Jul 15, 08:50 UTCJul 15, 10:15 UTC1h 25m
2026-07-14 GAXSW - Jul 14, 14:50 UTCJul 14, 15:40 UTC50m
2026-07-14 GAXSW BLK → BLK Jul 14, 13:00 UTCJul 14, 13:55 UTC55m
2026-07-14 GAXSW - Jul 14, 10:30 UTCJul 14, 11:35 UTC1h 5m
2026-07-14 GAXSW BLK → BLK Jul 14, 09:00 UTCJul 14, 09:40 UTC40m
2026-07-11 GAXSW BLK → BLK Jul 11, 11:25 UTCJul 11, 14:55 UTC3h 30m
2026-07-11 GAXSW BLK → BLK Jul 11, 09:20 UTCJul 11, 09:45 UTC25m
2026-07-10 GAXSW BLK → BLK Jul 10, 16:55 UTCJul 10, 17:55 UTC1h 0m
2026-07-10 GAXSW BLK → BLK Jul 10, 11:15 UTCJul 10, 14:40 UTC3h 25m
2026-07-10 GAXSW BLK → BLK Jul 10, 09:30 UTCJul 10, 10:35 UTC1h 5m
2026-07-02 GAXSW BLK → BLK Jul 2, 12:25 UTCJul 2, 13:20 UTC55m
2026-07-01 GAXSW - Jul 1, 13:15 UTCJul 1, 14:40 UTC1h 25m
2026-07-01 GAXSW BLK → BLK Jul 1, 10:55 UTCJul 1, 11:25 UTC30m
2026-06-30 GAXSW - Jun 30, 14:35 UTCJun 30, 15:10 UTC35m
2026-06-30 GAXSW - Jun 30, 12:40 UTCJun 30, 13:25 UTC45m
2026-06-30 GAXSW BLK → BLK Jun 30, 10:35 UTCJun 30, 11:20 UTC45m
2026-06-27 GAXSW - Jun 27, 14:14 UTCJun 27, 15:49 UTC1h 35m
2026-06-27 GAXSW - Jun 27, 11:09 UTCJun 27, 13:00 UTC1h 50m
2026-06-27 GAXSW BLK → BLK Jun 27, 09:44 UTCJun 27, 10:05 UTC20m
2026-06-26 GAXSW BLK → BLK Jun 26, 12:55 UTCJun 26, 13:49 UTC55m
2026-06-26 GAXSW BLK → BLK Jun 26, 09:00 UTCJun 26, 11:14 UTC2h 15m
2026-06-25 GAXSW - Jun 25, 13:29 UTCJun 25, 14:34 UTC1h 5m
2026-06-25 GAXSW - Jun 25, 11:35 UTCJun 25, 12:35 UTC1h 0m
2026-06-25 GAXSW - Jun 25, 08:55 UTCJun 25, 10:15 UTC1h 20m
2026-06-24 GAXSW - Jun 24, 13:50 UTCJun 24, 15:14 UTC1h 25m
2026-06-24 GAXSW - Jun 24, 11:34 UTCJun 24, 12:44 UTC1h 10m
2026-06-24 GAXSW BLK → BLK Jun 24, 08:39 UTCJun 24, 09:34 UTC55m
2026-06-23 GAXSW BLK → BLK Jun 23, 12:20 UTCJun 23, 12:55 UTC35m
2026-06-23 GAXSW BLK → BLK Jun 23, 10:39 UTCJun 23, 11:45 UTC1h 5m
2026-06-20 GAXSW BLK → BLK Jun 20, 13:49 UTCJun 20, 14:54 UTC1h 5m
2026-06-20 GAXSW - Jun 20, 10:34 UTCJun 20, 11:30 UTC55m
2026-06-20 GAXSW - Jun 20, 08:59 UTCJun 20, 09:54 UTC55m
2026-06-19 GAXSW BLK → BLK Jun 19, 12:34 UTCJun 19, 13:20 UTC45m
2026-06-18 GAXSW BLK → BLK Jun 18, 12:40 UTCJun 18, 13:45 UTC1h 5m
2026-06-18 GAXSW BLK → BLK Jun 18, 10:25 UTCJun 18, 11:25 UTC1h 0m
2026-06-18 GAXSW BLK → BLK Jun 18, 08:50 UTCJun 18, 09:55 UTC1h 5m

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-AXSW page for operator, model, and routing details .

Mode-S 401855 frequently asked

What is Mode-S code 401855?
401855 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-AXSW.
Where is Mode-S 401855 registered?
Mode-S code 401855 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 401855 broadcasting right now?
No active broadcast right now. Last signal was 7h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 401855, octal 20014125, decimal 4,200,533.
What flights does 401855 operate?
Mode-S 401855 has broadcast 1 distinct callsign, including GAXSW.