sensors Mode-S transponder

4081FB

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-XXEF · AGUSTA AW-139

Hex
4081FB
Octal
20100773
Decimal
4,227,579
Country
GB
Tail
G-XXEF
Type
A139
No current signal · last broadcast 1h ago
Flights observed
42
Distinct callsigns
2
Country
GB
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S 4081FB.

Country allocation

The ICAO 24-bit address 4081FB 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 2 distinct

Callsign Airline Flights Last seen
TKF1 - 39 2026-06-03
TKF2 - 3 2026-04-30

Recent flights last 42

DateFlightRouteTakeoffLandingDuration
2026-06-03 TKF1 - Jun 3, 09:35 UTCJun 3, 10:45 UTC1h 10m
2026-06-02 TKF1 - Jun 2, 15:25 UTCJun 2, 16:25 UTC1h 0m
2026-06-02 TKF1 - Jun 2, 11:35 UTCJun 2, 13:15 UTC1h 40m
2026-05-31 TKF1 - May 31, 09:30 UTCMay 31, 10:45 UTC1h 15m
2026-05-31 TKF1 - May 31, 08:25 UTCMay 31, 08:40 UTC15m
2026-05-26 TKF1 KNF → ODH May 26, 16:55 UTCMay 26, 18:05 UTC1h 10m
2026-05-26 TKF1 - May 26, 14:50 UTCMay 26, 16:00 UTC1h 10m
2026-05-26 TKF1 - May 26, 14:09 UTCMay 26, 14:14 UTC5m
2026-05-26 TKF1 - May 26, 08:24 UTCMay 26, 10:44 UTC2h 20m
2026-05-24 TKF1 - May 24, 09:50 UTCMay 24, 11:40 UTC1h 50m
2026-05-24 TKF1 - May 24, 09:10 UTCMay 24, 09:30 UTC20m
2026-05-22 TKF1 - May 22, 12:00 UTCMay 22, 12:55 UTC55m
2026-05-22 TKF1 - May 22, 08:25 UTCMay 22, 09:35 UTC1h 10m
2026-05-21 TKF1 - May 21, 11:35 UTCMay 21, 13:30 UTC1h 55m
2026-05-21 TKF1 - May 21, 09:10 UTCMay 21, 09:20 UTC10m
2026-05-20 TKF1 - May 20, 11:35 UTCMay 20, 12:05 UTC30m
2026-05-20 TKF1 - May 20, 09:00 UTCMay 20, 09:45 UTC45m
2026-05-19 TKF1 - May 19, 09:10 UTCMay 19, 11:05 UTC1h 55m
2026-05-13 TKF1 - May 13, 16:35 UTCMay 13, 17:00 UTC25m
2026-05-13 TKF1 - May 13, 14:00 UTCMay 13, 16:20 UTC2h 20m
2026-05-12 TKF1 - May 12, 07:55 UTCMay 12, 08:00 UTC5m
2026-05-11 TKF1 - May 11, 14:10 UTCMay 11, 14:25 UTC15m
2026-05-11 TKF1 - May 11, 08:25 UTCMay 11, 11:45 UTC3h 20m
2026-05-05 TKF1 - May 5, 14:25 UTCMay 5, 16:00 UTC1h 35m
2026-05-05 TKF1 ODH → KNF May 5, 08:45 UTCMay 5, 11:25 UTC2h 40m
2026-04-30 TKF2 JER → ODH Apr 30, 15:15 UTCApr 30, 16:55 UTC1h 40m
2026-04-30 TKF2 - Apr 30, 10:40 UTCApr 30, 12:00 UTC1h 21m
2026-04-30 TKF2 - Apr 30, 08:10 UTCApr 30, 09:05 UTC55m
2026-04-29 TKF1 GLA → ODH Apr 29, 15:00 UTCApr 29, 17:55 UTC2h 55m
2026-04-29 TKF1 - Apr 29, 11:25 UTCApr 29, 12:10 UTC45m
2026-04-28 TKF1 - Apr 28, 08:55 UTCApr 28, 09:10 UTC15m
2026-04-27 TKF1 - Apr 27, 10:55 UTCApr 27, 11:40 UTC45m
2026-04-27 TKF1 - Apr 27, 08:10 UTCApr 27, 10:25 UTC2h 15m
2026-04-25 TKF1 - Apr 25, 14:20 UTCApr 25, 15:15 UTC55m
2026-04-25 TKF1 - Apr 25, 10:05 UTCApr 25, 11:10 UTC1h 5m
2026-04-23 TKF1 - Apr 23, 15:05 UTCApr 23, 16:30 UTC1h 25m
2026-04-23 TKF1 ODH → BHX Apr 23, 08:55 UTCApr 23, 10:05 UTC1h 10m
2026-04-22 TKF1 - Apr 22, 10:50 UTCApr 22, 13:30 UTC2h 40m
2026-04-21 TKF1 - Apr 21, 13:01 UTCApr 21, 15:20 UTC2h 20m
2026-04-16 TKF1 - Apr 16, 13:54 UTCApr 16, 15:10 UTC1h 15m
2026-04-16 TKF1 - Apr 16, 09:10 UTCApr 16, 09:39 UTC30m
2026-04-16 TKF1 - Apr 16, 08:04 UTCApr 16, 09:05 UTC1h 0m

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

Mode-S 4081FB frequently asked

What is Mode-S code 4081FB?
4081FB is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-XXEF.
Where is Mode-S 4081FB registered?
Mode-S code 4081FB 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 4081FB 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 4081FB, octal 20100773, decimal 4,227,579.
What flights does 4081FB operate?
Mode-S 4081FB has broadcast 2 distinct callsigns, including TKF1, TKF2.