sensors Mode-S transponder

408143

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-DHMD · BOEING 777-200LR

Hex
408143
Octal
20100503
Decimal
4,227,395
Country
GB
Tail
G-DHMD
Type
B77L
No current signal · last broadcast 1d ago
Flights observed
5
Distinct callsigns
1
Country
GB
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 408143.

Country allocation

The ICAO 24-bit address 408143 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 1 distinct

Callsign Airline Flights Last seen
DHK004 - 5 2026-04-13

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-13 DHK004 - Apr 13, 08:35 UTCApr 13, 09:05 UTC30m
2026-04-13 DHK004 - Apr 13, 07:55 UTCApr 13, 09:05 UTC1h 10m
2026-04-13 DHK004 - Apr 13, 04:55 UTCApr 13, 08:15 UTC3h 20m
2026-04-13 DHK004 - Apr 13, 00:25 UTCApr 13, 02:10 UTC1h 45m
2026-04-12 DHK004 - Apr 12, 17:15 UTCApr 12, 17:25 UTC10m

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

Mode-S 408143 frequently asked

What is Mode-S code 408143?
408143 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-DHMD.
Where is Mode-S 408143 registered?
Mode-S code 408143 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 408143 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 408143, octal 20100503, decimal 4,227,395.
What flights does 408143 operate?
Mode-S 408143 has broadcast 1 distinct callsign, including DHK004.