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sensors Mode-S transponder

40556F

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-CEZI · PIPER PA-28-140/150/160/180

Hex
40556F
Octal
20052557
Decimal
4,216,175
Country
GB
Tail
G-CEZI
Type
P28A
No current signal · last broadcast 4h ago
Flights observed
121
Distinct callsigns
1
Country
GB
Last broadcast
4h ago

Last known position

Most recent position reported by Mode-S 40556F.

Country allocation

The ICAO 24-bit address 40556F 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
GCEZI - 120 2026-07-23

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-23 GCEZI - Jul 23, 11:50 UTCJul 23, 12:40 UTC50m
2026-07-23 GCEZI - Jul 23, 08:25 UTCJul 23, 09:20 UTC55m
2026-07-22 GCEZI - Jul 22, 15:25 UTCJul 22, 16:05 UTC40m
2026-07-22 GCEZI - Jul 22, 13:20 UTCJul 22, 14:30 UTC1h 10m
2026-07-21 GCEZI - Jul 21, 12:55 UTCJul 21, 13:55 UTC1h 0m
2026-07-21 GCEZI - Jul 21, 09:10 UTCJul 21, 11:00 UTC1h 50m
2026-07-20 GCEZI - Jul 20, 13:05 UTCJul 20, 13:25 UTC20m
2026-07-20 GCEZI - Jul 20, 10:20 UTCJul 20, 10:45 UTC25m
2026-07-19 GCEZI - Jul 19, 15:40 UTCJul 19, 16:15 UTC35m
2026-07-19 GCEZI - Jul 19, 12:45 UTCJul 19, 12:55 UTC10m
2026-07-19 GCEZI - Jul 19, 11:10 UTCJul 19, 11:50 UTC40m
2026-07-18 GCEZI - Jul 18, 15:30 UTCJul 18, 16:10 UTC40m
2026-07-18 GCEZI - Jul 18, 13:30 UTCJul 18, 13:50 UTC20m
2026-07-18 GCEZI - Jul 18, 11:35 UTCJul 18, 12:10 UTC35m
2026-07-18 GCEZI - Jul 18, 09:05 UTCJul 18, 09:55 UTC50m
2026-07-17 GCEZI - Jul 17, 13:20 UTCJul 17, 14:39 UTC1h 20m
2026-07-17 GCEZI - Jul 17, 10:50 UTCJul 17, 12:35 UTC1h 45m
2026-07-16 GCEZI - Jul 16, 14:15 UTCJul 16, 15:25 UTC1h 10m
2026-07-16 - - Jul 16, 10:45 UTCJul 16, 11:10 UTC25m
2026-07-15 GCEZI - Jul 15, 15:45 UTCJul 15, 16:20 UTC35m
2026-07-15 GCEZI - Jul 15, 13:05 UTCJul 15, 14:00 UTC55m
2026-07-15 GCEZI - Jul 15, 10:25 UTCJul 15, 11:10 UTC45m
2026-07-13 GCEZI - Jul 13, 14:05 UTCJul 13, 14:50 UTC45m
2026-07-13 GCEZI - Jul 13, 10:45 UTCJul 13, 11:30 UTC45m
2026-07-10 GCEZI - Jul 10, 16:50 UTCJul 10, 17:30 UTC40m
2026-07-10 GCEZI - Jul 10, 15:00 UTCJul 10, 15:45 UTC45m
2026-07-10 GCEZI - Jul 10, 10:05 UTCJul 10, 10:55 UTC50m
2026-07-09 GCEZI - Jul 9, 16:00 UTCJul 9, 17:15 UTC1h 15m
2026-07-09 GCEZI - Jul 9, 07:50 UTCJul 9, 08:05 UTC15m
2026-07-08 GCEZI - Jul 8, 10:00 UTCJul 8, 11:25 UTC1h 25m
2026-07-07 GCEZI - Jul 7, 16:40 UTCJul 7, 17:20 UTC40m
2026-07-07 GCEZI - Jul 7, 15:20 UTCJul 7, 15:50 UTC30m
2026-07-07 GCEZI - Jul 7, 09:40 UTCJul 7, 10:40 UTC1h 0m
2026-07-06 GCEZI - Jul 6, 14:45 UTCJul 6, 15:30 UTC45m
2026-07-06 GCEZI - Jul 6, 13:15 UTCJul 6, 13:55 UTC40m
2026-07-06 GCEZI - Jul 6, 11:55 UTCJul 6, 12:40 UTC45m
2026-07-05 GCEZI - Jul 5, 17:20 UTCJul 5, 17:55 UTC35m
2026-07-05 GCEZI - Jul 5, 15:15 UTCJul 5, 16:00 UTC45m
2026-07-04 GCEZI - Jul 4, 15:55 UTCJul 4, 16:30 UTC35m
2026-07-01 GCEZI - Jul 1, 15:00 UTCJul 1, 15:40 UTC40m
2026-07-01 GCEZI - Jul 1, 10:20 UTCJul 1, 11:00 UTC40m
2026-06-26 GCEZI - Jun 26, 17:15 UTCJun 26, 17:29 UTC15m
2026-06-24 GCEZI - Jun 24, 10:59 UTCJun 24, 11:34 UTC35m
2026-06-24 GCEZI - Jun 24, 09:09 UTCJun 24, 09:59 UTC50m
2026-06-22 GCEZI - Jun 22, 13:44 UTCJun 22, 14:10 UTC25m
2026-06-21 GCEZI - Jun 21, 14:19 UTCJun 21, 14:54 UTC35m
2026-06-21 GCEZI - Jun 21, 11:10 UTCJun 21, 11:59 UTC50m
2026-06-20 GCEZI - Jun 20, 09:05 UTCJun 20, 09:24 UTC20m
2026-06-18 GCEZI - Jun 18, 12:00 UTCJun 18, 12:25 UTC25m
2026-06-16 GCEZI - Jun 16, 09:20 UTCJun 16, 10:04 UTC45m

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

Mode-S 40556F frequently asked

What is Mode-S code 40556F?
40556F is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-CEZI.
Where is Mode-S 40556F registered?
Mode-S code 40556F 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 40556F broadcasting right now?
No active broadcast right now. Last signal was 4h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 40556F, octal 20052557, decimal 4,216,175.
What flights does 40556F operate?
Mode-S 40556F has broadcast 1 distinct callsign, including GCEZI.