Apparatus

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sensors Mode-S transponder

405BD3

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-CJKK · Schleicher ASK 21

Hex
405BD3
Octal
20055723
Decimal
4,217,811
Country
GB
Tail
G-CJKK
Type
GLID
No current signal · last broadcast 3d ago
Flights observed
38
Distinct callsigns
1
Country
GB
Last broadcast
3d ago

Last known position

Most recent position reported by Mode-S 405BD3.

Country allocation

The ICAO 24-bit address 405BD3 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
A12 - 38 2026-05-30

Recent flights last 38

DateFlightRouteTakeoffLandingDuration
2026-05-30 A12 UPV → UPV May 30, 14:40 UTCMay 30, 16:25 UTC1h 45m
2026-05-30 A12 UPV → UPV May 30, 13:20 UTCMay 30, 14:05 UTC45m
2026-05-30 A12 UPV → UPV May 30, 10:30 UTCMay 30, 12:45 UTC2h 15m
2026-05-25 A12 UPV → UPV May 25, 13:25 UTCMay 25, 14:55 UTC1h 30m
2026-05-25 A12 UPV → UPV May 25, 09:55 UTCMay 25, 12:25 UTC2h 30m
2026-05-24 A12 UPV → UPV May 24, 09:40 UTCMay 24, 14:45 UTC5h 5m
2026-05-23 A12 UPV → UPV May 23, 15:20 UTCMay 23, 15:50 UTC30m
2026-05-23 A12 UPV → UPV May 23, 13:30 UTCMay 23, 14:45 UTC1h 15m
2026-05-23 A12 UPV → UPV May 23, 11:55 UTCMay 23, 12:45 UTC50m
2026-05-15 A12 UPV → UPV May 15, 10:50 UTCMay 15, 11:05 UTC15m
2026-05-15 A12 UPV → UPV May 15, 08:55 UTCMay 15, 09:50 UTC55m
2026-05-15 A12 UPV → UPV May 15, 08:05 UTCMay 15, 08:20 UTC15m
2026-05-14 A12 UPV → UPV May 14, 08:10 UTCMay 14, 13:30 UTC5h 20m
2026-05-13 A12 UPV → UPV May 13, 11:30 UTCMay 13, 11:55 UTC25m
2026-05-13 A12 UPV → UPV May 13, 08:35 UTCMay 13, 09:15 UTC40m
2026-05-12 A12 UPV → UPV May 12, 12:25 UTCMay 12, 13:05 UTC40m
2026-05-12 A12 UPV → UPV May 12, 09:05 UTCMay 12, 11:10 UTC2h 5m
2026-05-11 A12 UPV → UPV May 11, 12:25 UTCMay 11, 15:10 UTC2h 45m
2026-05-11 A12 UPV → UPV May 11, 10:40 UTCMay 11, 11:20 UTC40m
2026-05-10 A12 UPV → UPV May 10, 10:45 UTCMay 10, 12:00 UTC1h 15m
2026-05-10 A12 UPV → UPV May 10, 08:54 UTCMay 10, 09:45 UTC50m
2026-05-09 A12 UPV → UPV May 9, 12:55 UTCMay 9, 16:15 UTC3h 20m
2026-05-09 A12 UPV → UPV May 9, 10:30 UTCMay 9, 12:15 UTC1h 45m
2026-05-08 A12 UPV → UPV May 8, 08:05 UTCMay 8, 11:09 UTC3h 5m
2026-05-07 A12 UPV → UPV May 7, 10:55 UTCMay 7, 14:55 UTC4h 0m
2026-05-07 A12 UPV → UPV May 7, 08:15 UTCMay 7, 09:15 UTC1h 0m
2026-05-06 A12 UPV → UPV May 6, 13:15 UTCMay 6, 15:00 UTC1h 45m
2026-05-06 A12 UPV → UPV May 6, 11:50 UTCMay 6, 12:10 UTC20m
2026-05-06 A12 UPV → UPV May 6, 08:05 UTCMay 6, 11:05 UTC3h 0m
2026-05-02 A12 UPV → UPV May 2, 09:55 UTCMay 2, 14:15 UTC4h 20m
2026-04-26 A12 UPV → UPV Apr 26, 10:25 UTCApr 26, 15:05 UTC4h 40m
2026-04-25 A12 UPV → UPV Apr 25, 13:55 UTCApr 25, 15:45 UTC1h 50m
2026-04-25 A12 UPV → UPV Apr 25, 13:15 UTCApr 25, 13:25 UTC10m
2026-04-25 A12 UPV → UPV Apr 25, 09:45 UTCApr 25, 12:45 UTC3h 0m
2026-04-19 A12 UPV → UPV Apr 19, 11:20 UTCApr 19, 16:05 UTC4h 45m
2026-04-19 A12 UPV → UPV Apr 19, 09:50 UTCApr 19, 10:45 UTC55m
2026-04-19 A12 UPV → UPV Apr 19, 08:50 UTCApr 19, 09:00 UTC10m
2026-04-18 A12 UPV → UPV Apr 18, 09:50 UTCApr 18, 16:10 UTC6h 20m

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

Mode-S 405BD3 frequently asked

What is Mode-S code 405BD3?
405BD3 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-CJKK.
Where is Mode-S 405BD3 registered?
Mode-S code 405BD3 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 405BD3 broadcasting right now?
No active broadcast right now. Last signal was 3d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 405BD3, octal 20055723, decimal 4,217,811.
What flights does 405BD3 operate?
Mode-S 405BD3 has broadcast 1 distinct callsign, including A12.