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sensors Mode-S transponder

4021F7

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-HULL · CESSNA 150

Hex
4021F7
Octal
20020767
Decimal
4,202,999
Country
GB
Tail
G-HULL
Type
C150
No current signal · last broadcast 16h ago
Flights observed
110
Distinct callsigns
1
Country
GB
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S 4021F7.

Country allocation

The ICAO 24-bit address 4021F7 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
GHULL - 110 2026-07-17

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-17 GHULL - Jul 17, 09:50 UTCJul 17, 10:15 UTC25m
2026-07-16 GHULL - Jul 16, 14:40 UTCJul 16, 15:10 UTC30m
2026-07-15 GHULL - Jul 15, 10:15 UTCJul 15, 10:55 UTC40m
2026-07-09 GHULL - Jul 9, 12:55 UTCJul 9, 13:10 UTC15m
2026-07-09 GHULL - Jul 9, 11:10 UTCJul 9, 11:35 UTC25m
2026-07-07 GHULL - Jul 7, 12:25 UTCJul 7, 13:05 UTC40m
2026-07-06 GHULL - Jul 6, 11:15 UTCJul 6, 12:25 UTC1h 10m
2026-07-06 GHULL - Jul 6, 10:00 UTCJul 6, 10:30 UTC30m
2026-07-05 GHULL - Jul 5, 14:20 UTCJul 5, 14:45 UTC25m
2026-07-05 GHULL - Jul 5, 13:05 UTCJul 5, 13:45 UTC40m
2026-07-04 GHULL - Jul 4, 13:30 UTCJul 4, 14:05 UTC35m
2026-07-04 GHULL - Jul 4, 12:10 UTCJul 4, 12:50 UTC40m
2026-07-04 GHULL - Jul 4, 08:25 UTCJul 4, 09:05 UTC40m
2026-07-01 GHULL - Jul 1, 15:40 UTCJul 1, 17:00 UTC1h 20m
2026-07-01 GHULL - Jul 1, 12:10 UTCJul 1, 12:55 UTC45m
2026-07-01 GHULL - Jul 1, 10:05 UTCJul 1, 11:30 UTC1h 25m
2026-07-01 GHULL - Jul 1, 08:45 UTCJul 1, 09:30 UTC45m
2026-06-30 GHULL - Jun 30, 09:35 UTCJun 30, 10:30 UTC55m
2026-06-28 GHULL - Jun 28, 14:19 UTCJun 28, 15:09 UTC50m
2026-06-28 GHULL - Jun 28, 13:04 UTCJun 28, 13:29 UTC25m
2026-06-28 GHULL - Jun 28, 11:35 UTCJun 28, 12:29 UTC55m
2026-06-28 GHULL - Jun 28, 10:04 UTCJun 28, 10:55 UTC50m
2026-06-28 GHULL - Jun 28, 08:39 UTCJun 28, 09:30 UTC50m
2026-06-27 GHULL - Jun 27, 07:24 UTCJun 27, 08:44 UTC1h 20m
2026-06-26 GHULL - Jun 26, 09:24 UTCJun 26, 12:10 UTC2h 45m
2026-06-21 GHULL - Jun 21, 12:55 UTCJun 21, 13:44 UTC50m
2026-06-21 GHULL - Jun 21, 11:20 UTCJun 21, 12:10 UTC50m
2026-06-18 GHULL - Jun 18, 08:35 UTCJun 18, 09:10 UTC35m
2026-06-15 GHULL - Jun 15, 06:00 UTCJun 15, 06:30 UTC30m
2026-06-14 GHULL - Jun 14, 13:15 UTCJun 14, 14:00 UTC45m
2026-06-14 GHULL - Jun 14, 11:30 UTCJun 14, 12:25 UTC55m
2026-06-14 GHULL - Jun 14, 10:05 UTCJun 14, 10:55 UTC50m
2026-06-14 GHULL - Jun 14, 08:40 UTCJun 14, 09:30 UTC50m
2026-06-13 GHULL - Jun 13, 14:10 UTCJun 13, 15:00 UTC50m
2026-06-13 GHULL - Jun 13, 12:25 UTCJun 13, 13:15 UTC50m
2026-06-13 GHULL - Jun 13, 10:45 UTCJun 13, 11:10 UTC25m
2026-06-13 GHULL - Jun 13, 09:45 UTCJun 13, 10:10 UTC25m
2026-06-13 GHULL - Jun 13, 08:25 UTCJun 13, 09:10 UTC45m
2026-06-12 GHULL - Jun 12, 10:50 UTCJun 12, 11:45 UTC55m
2026-06-12 GHULL - Jun 12, 08:55 UTCJun 12, 09:55 UTC1h 0m
2026-06-10 GHULL - Jun 10, 10:00 UTCJun 10, 10:50 UTC50m
2026-06-09 GHULL - Jun 9, 13:10 UTCJun 9, 13:55 UTC45m
2026-06-09 GHULL - Jun 9, 11:45 UTCJun 9, 12:30 UTC45m
2026-06-07 GHULL - Jun 7, 10:05 UTCJun 7, 12:15 UTC2h 10m
2026-06-07 GHULL - Jun 7, 08:35 UTCJun 7, 09:25 UTC50m
2026-06-06 GHULL - Jun 6, 16:20 UTCJun 6, 17:10 UTC50m
2026-06-06 GHULL - Jun 6, 14:45 UTCJun 6, 15:39 UTC55m
2026-06-06 GHULL - Jun 6, 12:45 UTCJun 6, 14:04 UTC1h 20m
2026-06-06 GHULL - Jun 6, 11:25 UTCJun 6, 12:14 UTC50m
2026-06-06 GHULL - Jun 6, 08:25 UTCJun 6, 10:14 UTC1h 50m

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

Mode-S 4021F7 frequently asked

What is Mode-S code 4021F7?
4021F7 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-HULL.
Where is Mode-S 4021F7 registered?
Mode-S code 4021F7 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 4021F7 broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4021F7, octal 20020767, decimal 4,202,999.
What flights does 4021F7 operate?
Mode-S 4021F7 has broadcast 1 distinct callsign, including GHULL.