sensors Mode-S transponder

4081D7

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-XLRB · AIRBUS A-321neo

Hex
4081D7
Octal
20100727
Decimal
4,227,543
Country
GB
Tail
G-XLRB
Type
A21N
No current signal · last broadcast 12h ago
Flights observed
7
Distinct callsigns
3
Country
GB
Last broadcast
12h ago

Last known position

Most recent position reported by Mode-S 4081D7.

Country allocation

The ICAO 24-bit address 4081D7 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 3 distinct

Callsign Airline Flights Last seen
WUK5608 - 3 2026-04-13
WUK5607 Wizz Air UK 3 2026-04-13
WUK2TN - 1 2026-04-14

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-14 WUK2TN - Apr 14, 09:50 UTCApr 14, 11:05 UTC1h 15m
2026-04-13 WUK5608 - Apr 13, 19:50 UTCApr 13, 21:10 UTC1h 20m
2026-04-13 WUK5608 - Apr 13, 17:30 UTCApr 13, 20:10 UTC2h 40m
2026-04-13 WUK5607 LGW → JED Apr 13, 08:20 UTCApr 13, 11:05 UTC2h 45m
2026-04-13 WUK5607 LGW → JED Apr 13, 07:55 UTCApr 13, 11:05 UTC3h 10m
2026-04-13 WUK5607 LGW → JED Apr 13, 07:20 UTCApr 13, 08:15 UTC55m
2026-04-12 WUK5608 - Apr 12, 17:35 UTCApr 12, 20:15 UTC2h 40m

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

Mode-S 4081D7 frequently asked

What is Mode-S code 4081D7?
4081D7 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-XLRB.
Where is Mode-S 4081D7 registered?
Mode-S code 4081D7 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 4081D7 broadcasting right now?
No active broadcast right now. Last signal was 12h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4081D7, octal 20100727, decimal 4,227,543.
What flights does 4081D7 operate?
Mode-S 4081D7 has broadcast 3 distinct callsigns, including WUK5608, WUK5607, WUK2TN.