sensors Mode-S transponder

4081A9

ICAO 24-bit transponder address · allocated to United Kingdom

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

Hex
4081A9
Octal
20100651
Decimal
4,227,497
Country
GB
Tail
G-HLYH
Type
A21N
No current signal · last broadcast 46m ago
Flights observed
338
Distinct callsigns
20
Country
GB
Last broadcast
46m ago

Last known position

Most recent position reported by Mode-S 4081A9.

Country allocation

The ICAO 24-bit address 4081A9 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
EXS77AW - 12 2026-07-01
EXS5TR - 12 2026-07-13
EXS5BC - 12 2026-07-01
EXS59ED - 12 2026-07-13
EXS8J - 10 2026-07-11
EXS75JU - 10 2026-07-11
EXS38KN - 9 2026-07-14
EXS93GN - 8 2026-07-07
EXS57N - 8 2026-07-04
EXS21NF - 8 2026-07-04
EXS87RH - 7 2026-06-28
EXS80DZ Jet2.com 7 2026-07-02
EXS64VW Jet2.com 7 2026-04-17
EXS4AN Jet2.com 7 2026-04-17
EXS14AM - 7 2026-07-02
EXS74NW - 6 2026-06-28
EXS17NY - 6 2026-04-16
EXS99AH - 5 2026-07-05
EXS75NE Jet2.com 5 2026-06-18
EXS69DB Jet2.com 5 2026-06-18

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 EXS89GV - Jul 14, 12:20 UTCJul 14, 14:15 UTC1h 55m
2026-07-14 EXS38KN EDI → ALC Jul 14, 06:30 UTCJul 14, 09:25 UTC2h 55m
2026-07-13 EXS38HA EFL → EDI Jul 13, 19:55 UTCJul 13, 23:40 UTC3h 45m
2026-07-13 EXS3929 EDI → EFL Jul 13, 15:20 UTCJul 13, 18:45 UTC3h 25m
2026-07-13 EXS59ED FAO → EDI Jul 13, 10:10 UTCJul 13, 12:55 UTC2h 45m
2026-07-13 EXS5TR - Jul 13, 05:55 UTCJul 13, 08:50 UTC2h 55m
2026-07-12 EXS3922 MLA → EDI Jul 12, 21:00 UTCJul 13, 00:40 UTC3h 40m
2026-07-12 EXS23T - Jul 12, 16:35 UTCJul 12, 19:50 UTC3h 15m
2026-07-12 EXS79E PVK → EDI Jul 12, 10:25 UTCJul 12, 14:01 UTC3h 35m
2026-07-12 EXS49FP - Jul 12, 05:55 UTCJul 12, 09:10 UTC3h 15m
2026-07-11 EXS34DA RHO → EDI Jul 11, 21:00 UTCJul 12, 01:20 UTC4h 20m
2026-07-11 EXS19E EDI → RHO Jul 11, 15:15 UTCJul 11, 19:20 UTC4h 5m
2026-07-11 EXS75JU - Jul 11, 10:40 UTCJul 11, 13:40 UTC3h 0m
2026-07-11 EXS8J - Jul 11, 05:55 UTCJul 11, 09:20 UTC3h 25m
2026-07-10 EXS89TS - Jul 10, 20:00 UTCJul 10, 23:55 UTC3h 55m
2026-07-10 EXS71KV MAN → GVA Jul 10, 13:50 UTCJul 10, 17:55 UTC4h 5m
2026-07-10 EXS89SM MAH → EDI Jul 10, 09:45 UTCJul 10, 12:15 UTC2h 30m
2026-07-10 EXS76DF EDI → MAH Jul 10, 05:55 UTCJul 10, 08:30 UTC2h 35m
2026-07-09 EXS35MD MAN → GVA Jul 9, 12:30 UTCJul 9, 16:15 UTC3h 45m
2026-07-09 EXS17XZ EDI → SKG Jul 9, 05:15 UTCJul 9, 08:25 UTC3h 10m
2026-07-08 EXS76RT - Jul 8, 19:00 UTCJul 8, 23:45 UTC4h 45m
2026-07-08 EXS87LS - Jul 8, 13:35 UTCJul 8, 17:30 UTC3h 55m
2026-07-08 EXS41JB - Jul 8, 09:35 UTCJul 8, 11:55 UTC2h 20m
2026-07-08 EXS3HE EDI → REU Jul 8, 05:30 UTCJul 8, 08:15 UTC2h 45m
2026-07-07 EXS93GN ALC → EDI Jul 7, 12:40 UTCJul 7, 15:35 UTC2h 55m
2026-07-07 EXS38KN - Jul 7, 08:30 UTCJul 7, 11:10 UTC2h 40m
2026-07-06 EXS3922 MLA → EDI Jul 6, 20:10 UTCJul 6, 23:55 UTC3h 45m
2026-07-06 EXS23T EDI → MLA Jul 6, 15:20 UTCJul 6, 18:35 UTC3h 15m
2026-07-06 EXS75JU - Jul 6, 10:25 UTCJul 6, 13:25 UTC3h 0m
2026-07-06 EXS8J - Jul 6, 05:55 UTCJul 6, 08:45 UTC2h 50m
2026-07-05 EXS99AH - Jul 5, 20:25 UTCJul 6, 00:30 UTC4h 5m
2026-07-05 EXS58YA - Jul 5, 14:50 UTCJul 5, 19:05 UTC4h 15m
2026-07-05 EXS59ED FAO → EDI Jul 5, 10:25 UTCJul 5, 13:25 UTC3h 0m
2026-07-05 EXS5TR EDI → FAO Jul 5, 06:00 UTCJul 5, 08:55 UTC2h 55m
2026-07-04 EXS57N - Jul 4, 20:20 UTCJul 5, 00:30 UTC4h 10m
2026-07-04 EXS21NF - Jul 4, 14:30 UTCJul 4, 18:50 UTC4h 20m
2026-07-04 EXS93GN - Jul 4, 09:25 UTCJul 4, 12:20 UTC2h 55m
2026-07-04 EXS38KN - Jul 4, 05:25 UTCJul 4, 08:00 UTC2h 35m
2026-07-03 EXS99AH - Jul 3, 20:30 UTCJul 4, 00:35 UTC4h 5m
2026-07-03 EXS58YA - Jul 3, 14:45 UTCJul 3, 19:05 UTC4h 20m
2026-07-03 EXS59ED FAO → EDI Jul 3, 10:30 UTCJul 3, 13:35 UTC3h 5m
2026-07-03 EXS5TR EDI → FAO Jul 3, 06:20 UTCJul 3, 09:20 UTC3h 0m
2026-07-02 EXS57N - Jul 2, 20:25 UTCJul 3, 00:35 UTC4h 10m
2026-07-02 EXS21NF - Jul 2, 14:45 UTCJul 2, 19:05 UTC4h 20m
2026-07-02 EXS80DZ GVA → EDI Jul 2, 10:50 UTCJul 2, 13:30 UTC2h 40m
2026-07-02 EXS14AM EDI → IBZ Jul 2, 06:35 UTCJul 2, 09:10 UTC2h 35m
2026-07-01 EXS76RT - Jul 1, 21:10 UTCJul 2, 01:35 UTC4h 25m
2026-07-01 EXS87LS EDI → AYT Jul 1, 14:05 UTCJul 1, 18:20 UTC4h 15m
2026-07-01 EXS5BC - Jul 1, 09:40 UTCJul 1, 12:35 UTC2h 55m
2026-07-01 EXS77AW - Jul 1, 05:45 UTCJul 1, 08:00 UTC2h 15m

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

Mode-S 4081A9 frequently asked

What is Mode-S code 4081A9?
4081A9 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-HLYH.
Where is Mode-S 4081A9 registered?
Mode-S code 4081A9 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 4081A9 broadcasting right now?
No active broadcast right now. Last signal was 46m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4081A9, octal 20100651, decimal 4,227,497.
What flights does 4081A9 operate?
Mode-S 4081A9 has broadcast 20 distinct callsigns, including EXS77AW, EXS5TR, EXS5BC, EXS59ED, EXS8J.