sensors Mode-S transponder

4C81EB

ICAO 24-bit transponder address · allocated to Cyprus

Hex
4C81EB
Octal
23100753
Decimal
5,013,995
Country
CY
No current signal · last broadcast 6d ago
Flights observed
1
Distinct callsigns
1
Country
CY
Last broadcast
6d ago

Last known position

Most recent position reported by Mode-S 4C81EB.

Country allocation

The ICAO 24-bit address 4C81EB falls within the block assigned to Cyprus (CY) by ICAO Annex 10, Volume III. Every aircraft registered in Cyprus 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
ASL136 Spurling Aviation 1 2026-05-23

Recent flights last 1

DateFlightRouteTakeoffLandingDuration
2026-05-23 ASL136 BEG → SVO May 23, 21:20 UTCMay 23, 21:30 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.

Mode-S 4C81EB frequently asked

What is Mode-S code 4C81EB?
4C81EB is an ICAO 24-bit transponder address. Allocated to Cyprus.
Where is Mode-S 4C81EB registered?
Mode-S code 4C81EB is allocated to Cyprus (CY). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4C81EB broadcasting right now?
No active broadcast right now. Last signal was 6d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4C81EB, octal 23100753, decimal 5,013,995.
What flights does 4C81EB operate?
Mode-S 4C81EB has broadcast 1 distinct callsign, including ASL136.