sensors Mode-S transponder

4C0223

ICAO 24-bit transponder address · allocated to Serbia

Currently assigned to YU-ARD · AIRBUS A-330-200

Hex
4C0223
Octal
23001043
Decimal
4,981,283
Country
RS
Tail
YU-ARD
Type
A332
No current signal · last broadcast 2h ago
Flights observed
5
Distinct callsigns
4
Country
RS
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S 4C0223.

Country allocation

The ICAO 24-bit address 4C0223 falls within the block assigned to Serbia (RS) by ICAO Annex 10, Volume III. Every aircraft registered in Serbia 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 4 distinct

Callsign Airline Flights Last seen
ASL989 Spurling Aviation 2 2026-04-20
ASL988 Spurling Aviation 1 2026-04-20
ASL501 Spurling Aviation 1 2026-04-19
ASL500 Spurling Aviation 1 2026-04-18

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-20 ASL989 CAN → BEG Apr 20, 20:05 UTCApr 21, 02:40 UTC6h 35m
2026-04-20 ASL989 CAN → BEG Apr 20, 00:50 UTCApr 20, 23:30 UTC22h 40m
2026-04-20 ASL988 BEG → CAN Apr 20, 00:00 UTCApr 20, 21:05 UTC21h 5m
2026-04-19 ASL501 JFK → BEG Apr 19, 00:25 UTCApr 19, 08:55 UTC8h 30m
2026-04-18 ASL500 BEG → JFK Apr 18, 12:20 UTCApr 18, 21:45 UTC9h 25m

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 YU-ARD page for operator, model, and routing details .

Mode-S 4C0223 frequently asked

What is Mode-S code 4C0223?
4C0223 is an ICAO 24-bit transponder address. Allocated to Serbia. Assigned to YU-ARD.
Where is Mode-S 4C0223 registered?
Mode-S code 4C0223 is allocated to Serbia (RS). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4C0223 broadcasting right now?
No active broadcast right now. Last signal was 2h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4C0223, octal 23001043, decimal 4,981,283.
What flights does 4C0223 operate?
Mode-S 4C0223 has broadcast 4 distinct callsigns, including ASL989, ASL988, ASL501, ASL500.