sensors Mode-S transponder

43C8EB

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to ZM517 · AIRBUS HELICOPTERS EC-135/635

Hex
43C8EB
Octal
20744353
Decimal
4,442,347
Country
GB
Tail
ZM517
Type
EC35
No current signal · last broadcast 15h ago
Flights observed
5
Distinct callsigns
5
Country
GB
Last broadcast
15h ago

Last known position

Most recent position reported by Mode-S 43C8EB.

Country allocation

The ICAO 24-bit address 43C8EB 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 5 distinct

Callsign Airline Flights Last seen
SYS98 - 1 2026-04-13
SYS56 - 1 2026-04-13
SYS27 - 1 2026-04-14
SYS135 - 1 2026-04-13
SYS10 - 1 2026-04-14

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-14 SYS10 - Apr 14, 10:25 UTCApr 14, 11:05 UTC40m
2026-04-14 SYS27 - Apr 14, 08:05 UTCApr 14, 09:05 UTC1h 0m
2026-04-13 SYS56 - Apr 13, 20:00 UTCApr 13, 23:20 UTC3h 20m
2026-04-13 SYS98 - Apr 13, 12:20 UTCApr 13, 15:40 UTC3h 20m
2026-04-13 SYS135 - Apr 13, 11:50 UTCApr 13, 12:15 UTC25m

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 ZM517 page for operator, model, and routing details .

Mode-S 43C8EB frequently asked

What is Mode-S code 43C8EB?
43C8EB is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to ZM517.
Where is Mode-S 43C8EB registered?
Mode-S code 43C8EB 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 43C8EB broadcasting right now?
No active broadcast right now. Last signal was 15h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 43C8EB, octal 20744353, decimal 4,442,347.
What flights does 43C8EB operate?
Mode-S 43C8EB has broadcast 5 distinct callsigns, including SYS98, SYS56, SYS27, SYS135, SYS10.