sensors Mode-S transponder

4081A1

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-TTSB · AIRBUS A-320neo

Hex
4081A1
Octal
20100641
Decimal
4,227,489
Country
GB
Tail
G-TTSB
Type
A20N
Broadcasting now · callsign BAW4EP · 12,975 ft
Flights observed
459
Distinct callsigns
20
Country
GB
Last broadcast
Jul 26, 18:45 UTC

Current position

4081A1 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 4081A1 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
BAW706 - 10 2026-07-01
BAW707 - 9 2026-07-01
BAW522 - 8 2026-07-18
BAW397 British Airways 7 2026-07-06
BAW523 - 6 2026-07-06
BAW396U - 6 2026-07-06
SHT14G - 5 2026-06-11
BAW639 - 5 2026-07-15
BAW638 - 5 2026-07-14
BAW521 British Airways 5 2026-06-16
BAW520R - 5 2026-06-16
SHT15B - 4 2026-06-11
BAW5PQ British Airways 4 2026-07-20
BAW547 - 4 2026-07-20
BAW439M - 4 2026-07-19
BAW438W - 4 2026-07-19
SHT9X - 3 2026-05-27
SHT8P - 3 2026-05-26
BAW99C - 3 2026-07-01
BAW998 - 3 2026-06-30

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 BAW689 IST → LHR Jul 26, 14:50 UTCJul 26, 18:45 UTC3h 55m
2026-07-26 BAW68TR LHR → JTR Jul 26, 09:40 UTCJul 26, 12:55 UTC3h 15m
2026-07-25 BAW691 - Jul 25, 13:55 UTCJul 25, 17:35 UTC3h 40m
2026-07-25 BAW690 LHR → LJU Jul 25, 08:45 UTCJul 25, 11:55 UTC3h 10m
2026-07-25 SHT15E JER → LHR Jul 25, 06:15 UTCJul 25, 07:00 UTC45m
2026-07-24 SHT14P - Jul 24, 19:00 UTCJul 24, 19:35 UTC35m
2026-07-24 BAW837 DUB → LHR Jul 24, 14:25 UTCJul 24, 17:00 UTC2h 35m
2026-07-24 BAW836 LHR → DUB Jul 24, 11:05 UTCJul 24, 13:15 UTC2h 10m
2026-07-24 BAW71LK LCA → LHR Jul 24, 04:40 UTCJul 24, 09:15 UTC4h 35m
2026-07-23 BAW710C LHR → LCA Jul 23, 18:45 UTCJul 23, 22:40 UTC3h 55m
2026-07-23 BAW65LG JMK → LHR Jul 23, 13:45 UTCJul 23, 17:10 UTC3h 25m
2026-07-23 BAW26AV LHR → ATH Jul 23, 08:40 UTCJul 23, 11:45 UTC3h 5m
2026-07-23 BAW741 GVA → LHR Jul 23, 05:30 UTCJul 23, 06:55 UTC1h 25m
2026-07-22 BAW740 LHR → HER Jul 22, 19:15 UTCJul 22, 20:25 UTC1h 10m
2026-07-22 BAW667 - Jul 22, 13:25 UTCJul 22, 17:10 UTC3h 45m
2026-07-22 BAW66K LHR → JMK Jul 22, 11:10 UTCJul 22, 11:45 UTC35m
2026-07-21 BAW756 LHR → BSL Jul 21, 19:20 UTCJul 21, 20:30 UTC1h 10m
2026-07-21 SHT17L - Jul 21, 16:20 UTCJul 21, 17:20 UTC1h 0m
2026-07-21 SHT16E - Jul 21, 13:15 UTCJul 21, 14:25 UTC1h 10m
2026-07-21 BAW341 - Jul 21, 10:05 UTCJul 21, 11:45 UTC1h 40m
2026-07-21 BAW340E - Jul 21, 05:55 UTCJul 21, 07:30 UTC1h 35m
2026-07-20 BAW451 IBZ → LHR Jul 20, 17:50 UTCJul 20, 19:50 UTC2h 0m
2026-07-20 BAW450 - Jul 20, 14:40 UTCJul 20, 16:40 UTC2h 0m
2026-07-20 BAW547 - Jul 20, 10:05 UTCJul 20, 12:20 UTC2h 15m
2026-07-20 BAW5PQ LHR → FCO Jul 20, 05:55 UTCJul 20, 07:50 UTC1h 55m
2026-07-19 BAW439M AMS → LHR Jul 19, 18:05 UTCJul 19, 19:00 UTC55m
2026-07-19 BAW438W - Jul 19, 16:00 UTCJul 19, 16:45 UTC45m
2026-07-19 BAW921 - Jul 19, 12:40 UTCJul 19, 14:00 UTC1h 20m
2026-07-19 BAW920U LHR → DUS Jul 19, 10:25 UTCJul 19, 11:15 UTC50m
2026-07-19 BAW4EP - Jul 19, 05:15 UTCJul 19, 07:15 UTC2h 0m
2026-07-18 BAW522 - Jul 18, 18:20 UTCJul 18, 19:55 UTC1h 35m
2026-07-18 BAW691 - Jul 18, 13:10 UTCJul 18, 16:50 UTC3h 40m
2026-07-18 BAW690 - Jul 18, 08:30 UTCJul 18, 11:40 UTC3h 10m
2026-07-18 BAW757A GVA → LHR Jul 18, 05:35 UTCJul 18, 07:05 UTC1h 30m
2026-07-17 BAW756 - Jul 17, 19:45 UTCJul 17, 20:55 UTC1h 10m
2026-07-17 BAW553C - Jul 17, 15:40 UTCJul 17, 17:55 UTC2h 15m
2026-07-17 BAW552F - Jul 17, 10:20 UTCJul 17, 12:19 UTC2h 0m
2026-07-17 BAW729 GVA → LHR Jul 17, 06:45 UTCJul 17, 08:49 UTC2h 5m
2026-07-16 BAW78H - Jul 16, 19:14 UTCJul 16, 20:49 UTC1h 35m
2026-07-16 BAW725 VIE → LHR Jul 16, 15:10 UTCJul 16, 17:05 UTC1h 55m
2026-07-16 BAW72J - Jul 16, 12:14 UTCJul 16, 13:54 UTC1h 40m
2026-07-16 BAW337 NCE → LHR Jul 16, 08:55 UTCJul 16, 10:50 UTC1h 55m
2026-07-16 BAW336 - Jul 16, 05:30 UTCJul 16, 07:00 UTC1h 30m
2026-07-15 BAW689 - Jul 15, 15:50 UTCJul 15, 19:30 UTC3h 40m
2026-07-15 BAW68TR - Jul 15, 10:10 UTCJul 15, 13:15 UTC3h 5m
2026-07-15 BAW639 - Jul 15, 04:45 UTCJul 15, 08:45 UTC4h 0m
2026-07-14 BAW638 - Jul 14, 20:25 UTCJul 14, 23:20 UTC2h 54m
2026-07-14 BAW577 LIN → LHR Jul 14, 17:00 UTCJul 14, 18:45 UTC1h 45m
2026-07-14 BAW576 - Jul 14, 13:35 UTCJul 14, 15:00 UTC1h 25m
2026-07-14 BAW547 - Jul 14, 09:45 UTCJul 14, 11:55 UTC2h 10m

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

Mode-S 4081A1 frequently asked

What is Mode-S code 4081A1?
4081A1 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-TTSB.
Where is Mode-S 4081A1 registered?
Mode-S code 4081A1 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 4081A1 broadcasting right now?
Yes. Mode-S 4081A1 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4081A1, octal 20100641, decimal 4,227,489.
What flights does 4081A1 operate?
Mode-S 4081A1 has broadcast 20 distinct callsigns, including BAW706, BAW707, BAW522, BAW397, BAW523.