sensors Mode-S transponder

40838E

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-THDA · AGUSTA AW-109 Grand

Hex
40838E
Octal
20101616
Decimal
4,227,982
Country
GB
Tail
G-THDA
Type
A109
No current signal · last broadcast 19h ago
Flights observed
84
Distinct callsigns
2
Country
GB
Last broadcast
19h ago

Last known position

Most recent position reported by Mode-S 40838E.

Country allocation

The ICAO 24-bit address 40838E 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
SXN21 - 73 2026-05-29
GTHDA - 11 2026-05-24

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 SXN21 - May 29, 09:55 UTCMay 29, 10:55 UTC1h 0m
2026-05-28 SXN21 - May 28, 15:10 UTCMay 28, 15:20 UTC10m
2026-05-28 SXN21 - May 28, 14:05 UTCMay 28, 14:55 UTC50m
2026-05-28 SXN21 - May 28, 07:25 UTCMay 28, 08:20 UTC55m
2026-05-27 SXN21 - May 27, 15:20 UTCMay 27, 15:45 UTC25m
2026-05-27 SXN21 - May 27, 12:50 UTCMay 27, 13:20 UTC30m
2026-05-27 SXN21 - May 27, 09:50 UTCMay 27, 10:00 UTC10m
2026-05-27 SXN21 - May 27, 09:00 UTCMay 27, 09:10 UTC10m
2026-05-25 SXN21 - May 25, 14:50 UTCMay 25, 16:55 UTC2h 5m
2026-05-25 SXN21 - May 25, 09:00 UTCMay 25, 09:20 UTC20m
2026-05-25 SXN21 - May 25, 08:15 UTCMay 25, 08:25 UTC10m
2026-05-24 GTHDA - May 24, 11:05 UTCMay 24, 11:45 UTC40m
2026-05-23 GTHDA - May 23, 16:10 UTCMay 23, 16:50 UTC40m
2026-05-22 SXN21 - May 22, 21:20 UTCMay 22, 21:50 UTC30m
2026-05-22 SXN21 - May 22, 20:20 UTCMay 22, 21:00 UTC40m
2026-05-22 SXN21 - May 22, 19:15 UTCMay 22, 19:30 UTC15m
2026-05-22 SXN21 - May 22, 17:35 UTCMay 22, 18:15 UTC40m
2026-05-22 SXN21 - May 22, 09:40 UTCMay 22, 10:45 UTC1h 5m
2026-05-21 SXN21 - May 21, 13:05 UTCMay 21, 13:45 UTC40m
2026-05-21 SXN21 - May 21, 09:25 UTCMay 21, 10:15 UTC50m
2026-05-21 SXN21 - May 21, 08:15 UTCMay 21, 08:50 UTC35m
2026-05-21 SXN21 - May 21, 07:10 UTCMay 21, 07:40 UTC30m
2026-05-18 SXN21 - May 18, 14:35 UTCMay 18, 15:15 UTC40m
2026-05-18 SXN21 - May 18, 08:50 UTCMay 18, 09:25 UTC35m
2026-05-18 SXN21 - May 18, 07:30 UTCMay 18, 07:45 UTC15m
2026-05-17 SXN21 - May 17, 16:01 UTCMay 17, 17:10 UTC1h 10m
2026-05-14 GTHDA - May 14, 16:40 UTCMay 14, 18:05 UTC1h 25m
2026-05-14 GTHDA - May 14, 13:35 UTCMay 14, 14:15 UTC40m
2026-05-14 GTHDA - May 14, 08:30 UTCMay 14, 09:10 UTC40m
2026-05-14 GTHDA - May 14, 07:00 UTCMay 14, 07:40 UTC40m
2026-05-12 GTHDA - May 12, 13:30 UTCMay 12, 14:50 UTC1h 20m
2026-05-12 GTHDA - May 12, 11:15 UTCMay 12, 12:35 UTC1h 20m
2026-05-12 SXN21 - May 12, 06:30 UTCMay 12, 08:55 UTC2h 25m
2026-05-10 SXN21 - May 10, 16:20 UTCMay 10, 16:55 UTC35m
2026-05-10 SXN21 - May 10, 09:50 UTCMay 10, 11:30 UTC1h 40m
2026-05-08 SXN21 - May 8, 16:40 UTCMay 8, 17:15 UTC35m
2026-05-08 SXN21 - May 8, 15:25 UTCMay 8, 15:50 UTC25m
2026-05-08 SXN21 - May 8, 14:50 UTCMay 8, 15:20 UTC30m
2026-05-08 SXN21 - May 8, 08:55 UTCMay 8, 10:04 UTC1h 10m
2026-05-07 SXN21 - May 7, 18:55 UTCMay 7, 20:25 UTC1h 30m
2026-05-07 GTHDA - May 7, 12:40 UTCMay 7, 14:55 UTC2h 15m
2026-05-07 GTHDA - May 7, 06:25 UTCMay 7, 09:00 UTC2h 35m
2026-05-06 SXN21 - May 6, 14:45 UTCMay 6, 16:10 UTC1h 25m
2026-05-06 SXN21 - May 6, 10:15 UTCMay 6, 12:25 UTC2h 10m
2026-05-06 SXN21 - May 6, 09:05 UTCMay 6, 09:40 UTC35m
2026-05-06 SXN21 - May 6, 08:05 UTCMay 6, 08:35 UTC30m
2026-05-05 SXN21 - May 5, 18:30 UTCMay 5, 19:05 UTC35m
2026-05-05 SXN21 - May 5, 11:20 UTCMay 5, 12:10 UTC50m
2026-05-05 SXN21 - May 5, 08:35 UTCMay 5, 09:25 UTC50m
2026-05-04 SXN21 - May 4, 17:30 UTCMay 4, 18:30 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-THDA page for operator, model, and routing details .

Mode-S 40838E frequently asked

What is Mode-S code 40838E?
40838E is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-THDA.
Where is Mode-S 40838E registered?
Mode-S code 40838E 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 40838E broadcasting right now?
No active broadcast right now. Last signal was 19h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 40838E, octal 20101616, decimal 4,227,982.
What flights does 40838E operate?
Mode-S 40838E has broadcast 2 distinct callsigns, including SXN21, GTHDA.