sensors Mode-S transponder

4081BB

ICAO 24-bit transponder address · allocated to United Kingdom

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

Hex
4081BB
Octal
20100673
Decimal
4,227,515
Country
GB
Tail
G-TNEF
Type
A21N
No current signal · last broadcast 1h ago
Flights observed
419
Distinct callsigns
20
Country
GB
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S 4081BB.

Country allocation

The ICAO 24-bit address 4081BB 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 20 distinct

Callsign Airline Flights Last seen
BAW399 - 6 2026-07-14
BAW398 - 6 2026-07-13
BAW63VP British Airways 5 2026-05-16
BAW509 British Airways 5 2026-05-28
BAW835W British Airways 4 2026-06-15
BAW834 British Airways 4 2026-06-15
BAW630 British Airways 4 2026-05-16
BAW569J - 4 2026-07-09
BAW568J - 4 2026-07-09
BAW551G British Airways 4 2026-06-18
SHT9X - 3 2026-07-13
SHT8P - 3 2026-07-12
SHT7B - 3 2026-07-06
SHT6U - 3 2026-07-05
SHT3R - 3 2026-05-30
SHT2P - 3 2026-05-30
BAW99C - 3 2026-06-25
BAW998 - 3 2026-06-24
BAW990G British Airways 3 2026-05-11
BAW971 British Airways 3 2026-05-16

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 BAW399 - Jul 14, 04:40 UTCJul 14, 09:40 UTC5h 0m
2026-07-13 BAW398 - Jul 13, 18:25 UTCJul 13, 22:35 UTC4h 10m
2026-07-13 BAW527 - Jul 13, 13:40 UTCJul 13, 16:05 UTC2h 25m
2026-07-13 BAW526 - Jul 13, 09:35 UTCJul 13, 11:35 UTC2h 0m
2026-07-13 SHT9X EDI → LHR Jul 13, 06:15 UTCJul 13, 07:15 UTC1h 0m
2026-07-12 SHT8P - Jul 12, 21:15 UTCJul 12, 22:05 UTC50m
2026-07-12 BAW673 SKG → LHR Jul 12, 15:10 UTCJul 12, 18:20 UTC3h 10m
2026-07-12 BAW672 - Jul 12, 08:20 UTCJul 12, 11:01 UTC2h 40m
2026-07-11 BAW413 - Jul 11, 17:45 UTCJul 11, 21:00 UTC3h 15m
2026-07-11 BAW412 - Jul 11, 12:45 UTCJul 11, 16:20 UTC3h 35m
2026-07-11 BAW343E NCE → LHR Jul 11, 09:15 UTCJul 11, 10:55 UTC1h 40m
2026-07-11 BAW342N LHR → NCE Jul 11, 05:35 UTCJul 11, 07:20 UTC1h 45m
2026-07-10 BAW33A ATH → LHR Jul 10, 18:10 UTCJul 10, 21:40 UTC3h 30m
2026-07-10 BAW32T - Jul 10, 13:45 UTCJul 10, 16:50 UTC3h 5m
2026-07-10 SHT9B - Jul 10, 10:50 UTCJul 10, 11:55 UTC1h 5m
2026-07-10 SHT8R LHR → EDI Jul 10, 08:20 UTCJul 10, 09:15 UTC55m
2026-07-10 SHT9E EDI → LHR Jul 10, 05:40 UTCJul 10, 06:40 UTC1h 0m
2026-07-09 SHT8V - Jul 9, 20:10 UTCJul 9, 21:05 UTC55m
2026-07-09 BAW557H - Jul 9, 16:25 UTCJul 9, 18:25 UTC2h 0m
2026-07-09 BAW556Q - Jul 9, 12:50 UTCJul 9, 14:45 UTC1h 55m
2026-07-09 BAW569J LIN → LHR Jul 9, 09:20 UTCJul 9, 11:05 UTC1h 45m
2026-07-09 BAW568J LHR → LIN Jul 9, 06:10 UTCJul 9, 07:40 UTC1h 30m
2026-07-08 SHT19Q ABZ → LHR Jul 8, 19:25 UTCJul 8, 20:30 UTC1h 5m
2026-07-08 SHT18H - Jul 8, 17:15 UTCJul 8, 18:20 UTC1h 5m
2026-07-08 BAW43XP - Jul 8, 14:50 UTCJul 8, 15:35 UTC45m
2026-07-08 BAW3ET - Jul 8, 12:30 UTCJul 8, 13:15 UTC45m
2026-07-08 BAW5GU - Jul 8, 08:05 UTCJul 8, 10:05 UTC2h 0m
2026-07-07 BAW544K - Jul 7, 20:10 UTCJul 7, 21:40 UTC1h 30m
2026-07-07 SHT7P - Jul 7, 16:20 UTCJul 7, 17:15 UTC55m
2026-07-07 SHT6F LHR → GLA Jul 7, 14:10 UTCJul 7, 15:15 UTC1h 5m
2026-07-07 BAW45EM MAD → LHR Jul 7, 10:40 UTCJul 7, 12:25 UTC1h 45m
2026-07-07 BAW4MJ - Jul 7, 07:10 UTCJul 7, 09:00 UTC1h 50m
2026-07-06 BAW755 - Jul 6, 19:40 UTCJul 6, 20:50 UTC1h 10m
2026-07-06 BAW754 - Jul 6, 17:15 UTCJul 6, 18:25 UTC1h 10m
2026-07-06 BAW513 FAO → LHR Jul 6, 12:45 UTCJul 6, 15:05 UTC2h 20m
2026-07-06 BAW512 - Jul 6, 08:25 UTCJul 6, 10:40 UTC2h 15m
2026-07-06 SHT7B - Jul 6, 05:00 UTCJul 6, 05:55 UTC55m
2026-07-05 SHT6U - Jul 5, 21:35 UTCJul 5, 22:25 UTC50m
2026-07-05 SHT19B ABZ → LHR Jul 5, 18:10 UTCJul 5, 19:10 UTC1h 0m
2026-07-05 SHT18A - Jul 5, 16:00 UTCJul 5, 17:05 UTC1h 5m
2026-07-05 BAW511 FAO → LHR Jul 5, 11:35 UTCJul 5, 14:20 UTC2h 45m
2026-07-05 BAW510 LHR → FAO Jul 5, 07:30 UTCJul 5, 09:50 UTC2h 20m
2026-07-04 BAW499 - Jul 4, 17:00 UTCJul 4, 19:00 UTC2h 0m
2026-07-04 BAW2LY LHR → PMI Jul 4, 13:50 UTCJul 4, 15:40 UTC1h 50m
2026-07-04 BAW475E BCN → LHR Jul 4, 10:10 UTCJul 4, 11:55 UTC1h 45m
2026-07-04 BAW474K - Jul 4, 07:20 UTCJul 4, 08:50 UTC1h 30m
2026-07-03 BAW7PI - Jul 3, 19:40 UTCJul 3, 20:50 UTC1h 10m
2026-07-03 BAW762 - Jul 3, 15:10 UTCJul 3, 16:30 UTC1h 20m
2026-07-03 BAW801 - Jul 3, 11:15 UTCJul 3, 13:40 UTC2h 25m
2026-07-03 BAW800 - Jul 3, 07:05 UTCJul 3, 10:00 UTC2h 55m

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

Mode-S 4081BB frequently asked

What is Mode-S code 4081BB?
4081BB is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-TNEF.
Where is Mode-S 4081BB registered?
Mode-S code 4081BB 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 4081BB broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4081BB, octal 20100673, decimal 4,227,515.
What flights does 4081BB operate?
Mode-S 4081BB has broadcast 20 distinct callsigns, including BAW399, BAW398, BAW63VP, BAW509, BAW835W.