sensors Mode-S transponder

407A43

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-JDUN · ROBINSON R-66

Hex
407A43
Octal
20075103
Decimal
4,225,603
Country
GB
Tail
G-JDUN
Type
R66
No current signal · last broadcast 22h ago
Flights observed
1
Distinct callsigns
1
Country
GB
Last broadcast
22h ago

Last known position

Most recent position reported by Mode-S 407A43.

Country allocation

The ICAO 24-bit address 407A43 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
GILLL - 1 2026-04-14

Recent flights last 1

DateFlightRouteTakeoffLandingDuration
2026-04-14 GILLL - Apr 14, 09:25 UTCApr 14, 09:40 UTC15m

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

Mode-S 407A43 frequently asked

What is Mode-S code 407A43?
407A43 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-JDUN.
Where is Mode-S 407A43 registered?
Mode-S code 407A43 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 407A43 broadcasting right now?
No active broadcast right now. Last signal was 22h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 407A43, octal 20075103, decimal 4,225,603.
What flights does 407A43 operate?
Mode-S 407A43 has broadcast 1 distinct callsign, including GILLL.