sensors Mode-S transponder

404B2B

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-CCTR · BEST OFF Sky Ranger

Hex
404B2B
Octal
20045453
Decimal
4,213,547
Country
GB
Tail
G-CCTR
Type
SKRA
No current signal · last broadcast 4d ago
Flights observed
25
Distinct callsigns
1
Country
GB
Last broadcast
4d ago

Last known position

Most recent position reported by Mode-S 404B2B.

Country allocation

The ICAO 24-bit address 404B2B 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
GCCTR - 25 2026-05-30

Recent flights last 25

DateFlightRouteTakeoffLandingDuration
2026-05-30 GCCTR - May 30, 14:40 UTCMay 30, 15:05 UTC25m
2026-05-30 GCCTR - May 30, 12:15 UTCMay 30, 13:50 UTC1h 35m
2026-05-30 GCCTR - May 30, 09:10 UTCMay 30, 10:15 UTC1h 5m
2026-05-28 GCCTR - May 28, 13:35 UTCMay 28, 14:20 UTC45m
2026-05-24 GCCTR - May 24, 14:05 UTCMay 24, 15:55 UTC1h 50m
2026-05-24 GCCTR - May 24, 08:35 UTCMay 24, 10:30 UTC1h 55m
2026-05-23 GCCTR - May 23, 13:50 UTCMay 23, 14:25 UTC35m
2026-05-23 GCCTR - May 23, 11:00 UTCMay 23, 11:50 UTC50m
2026-05-07 GCCTR - May 7, 13:40 UTCMay 7, 14:50 UTC1h 10m
2026-05-07 GCCTR - May 7, 10:25 UTCMay 7, 12:00 UTC1h 35m
2026-05-02 GCCTR - May 2, 11:55 UTCMay 2, 13:10 UTC1h 15m
2026-05-02 GCCTR - May 2, 09:15 UTCMay 2, 09:40 UTC25m
2026-05-02 GCCTR - May 2, 07:20 UTCMay 2, 08:30 UTC1h 10m
2026-04-26 GCCTR - Apr 26, 16:00 UTCApr 26, 16:30 UTC30m
2026-04-26 GCCTR - Apr 26, 14:40 UTCApr 26, 15:15 UTC35m
2026-04-25 GCCTR - Apr 25, 15:40 UTCApr 25, 16:45 UTC1h 5m
2026-04-25 GCCTR - Apr 25, 12:50 UTCApr 25, 13:55 UTC1h 5m
2026-04-23 GCCTR - Apr 23, 17:30 UTCApr 23, 18:00 UTC29m
2026-04-23 GCCTR - Apr 23, 14:45 UTCApr 23, 15:15 UTC30m
2026-04-19 GCCTR - Apr 19, 13:25 UTCApr 19, 15:00 UTC1h 35m
2026-04-19 GCCTR - Apr 19, 10:25 UTCApr 19, 12:00 UTC1h 35m
2026-04-18 GCCTR - Apr 18, 17:20 UTCApr 18, 18:05 UTC45m
2026-04-18 GCCTR - Apr 18, 13:15 UTCApr 18, 15:30 UTC2h 15m
2026-04-18 GCCTR - Apr 18, 08:50 UTCApr 18, 09:20 UTC30m
2026-04-13 GCCTR - Apr 13, 12:45 UTCApr 13, 13:15 UTC30m

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

Mode-S 404B2B frequently asked

What is Mode-S code 404B2B?
404B2B is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-CCTR.
Where is Mode-S 404B2B registered?
Mode-S code 404B2B 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 404B2B broadcasting right now?
No active broadcast right now. Last signal was 4d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 404B2B, octal 20045453, decimal 4,213,547.
What flights does 404B2B operate?
Mode-S 404B2B has broadcast 1 distinct callsign, including GCCTR.