sensors Mode-S transponder

4081BC

ICAO 24-bit transponder address · allocated to United Kingdom

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

Hex
4081BC
Octal
20100674
Decimal
4,227,516
Country
GB
Tail
G-TNEG
Type
A21N
No current signal · last broadcast 14h ago
Flights observed
11
Distinct callsigns
8
Country
GB
Last broadcast
14h ago

Last known position

Most recent position reported by Mode-S 4081BC.

Country allocation

The ICAO 24-bit address 4081BC 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 8 distinct

Callsign Airline Flights Last seen
BAW639 - 2 2026-04-14
BAW568J - 2 2026-04-13
BAW36LU British Airways 2 2026-04-13
BAW835W - 1 2026-04-12
BAW834 - 1 2026-04-12
BAW638 British Airways 1 2026-04-13
BAW569J British Airways 1 2026-04-13
BAW362Y British Airways 1 2026-04-13

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-14 BAW639 - Apr 14, 07:10 UTCApr 14, 08:40 UTC1h 30m
2026-04-14 BAW639 - Apr 14, 05:15 UTCApr 14, 07:10 UTC1h 55m
2026-04-13 BAW638 LHR → ATH Apr 13, 20:05 UTCApr 13, 23:20 UTC3h 15m
2026-04-13 BAW36LU LYS → LHR Apr 13, 16:15 UTCApr 13, 17:00 UTC45m
2026-04-13 BAW36LU LYS → LHR Apr 13, 15:50 UTCApr 13, 16:15 UTC25m
2026-04-13 BAW362Y LHR → LYS Apr 13, 13:15 UTCApr 13, 14:35 UTC1h 20m
2026-04-13 BAW569J LIN → LHR Apr 13, 09:40 UTCApr 13, 11:05 UTC1h 25m
2026-04-13 BAW568J - Apr 13, 07:55 UTCApr 13, 08:05 UTC10m
2026-04-13 BAW568J FAB → LIN Apr 13, 06:30 UTCApr 13, 08:05 UTC1h 35m
2026-04-12 BAW835W - Apr 12, 19:30 UTCApr 12, 20:15 UTC45m
2026-04-12 BAW834 - Apr 12, 17:25 UTCApr 12, 18:10 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-TNEG page for operator, model, and routing details .

Mode-S 4081BC frequently asked

What is Mode-S code 4081BC?
4081BC is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-TNEG.
Where is Mode-S 4081BC registered?
Mode-S code 4081BC 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 4081BC broadcasting right now?
No active broadcast right now. Last signal was 14h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4081BC, octal 20100674, decimal 4,227,516.
What flights does 4081BC operate?
Mode-S 4081BC has broadcast 8 distinct callsigns, including BAW639, BAW568J, BAW36LU, BAW835W, BAW834.