sensors Mode-S transponder

4C01F2

ICAO 24-bit transponder address · allocated to Serbia

Currently assigned to YU-APS · AIRBUS A-320

Hex
4C01F2
Octal
23000762
Decimal
4,981,234
Country
RS
Tail
YU-APS
Type
A320
No current signal · last broadcast 15h ago
Flights observed
9
Distinct callsigns
8
Country
RS
Last broadcast
15h ago

Last known position

Most recent position reported by Mode-S 4C01F2.

Country allocation

The ICAO 24-bit address 4C01F2 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 8 distinct

Callsign Airline Flights Last seen
ASL15M - 2 2026-04-13
ASL63H - 1 2026-04-13
ASL53X - 1 2026-04-14
ASL53L - 1 2026-04-13
ASL51N Spurling Aviation 1 2026-04-13
ASL49U - 1 2026-04-12
ASL42A - 1 2026-04-14
ASL20K Spurling Aviation 1 2026-04-14

Recent flights last 9

DateFlightRouteTakeoffLandingDuration
2026-04-14 ASL53X - Apr 14, 10:40 UTCApr 14, 11:05 UTC25m
2026-04-14 ASL20K AMS → BEG Apr 14, 07:55 UTCApr 14, 09:00 UTC1h 5m
2026-04-14 ASL42A - Apr 14, 05:15 UTCApr 14, 06:15 UTC1h 0m
2026-04-13 ASL15M BEG → BEG Apr 13, 19:45 UTCApr 13, 19:50 UTC5m
2026-04-13 ASL15M MAD → BEG Apr 13, 17:10 UTCApr 13, 19:50 UTC2h 40m
2026-04-13 ASL53L - Apr 13, 12:35 UTCApr 13, 15:35 UTC3h 0m
2026-04-13 ASL51N BEG → BEG Apr 13, 08:35 UTCApr 13, 10:45 UTC2h 10m
2026-04-13 ASL63H BEG → BCN Apr 13, 04:40 UTCApr 13, 06:55 UTC2h 15m
2026-04-12 ASL49U - Apr 12, 17:15 UTCApr 12, 18:20 UTC1h 5m

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

Mode-S 4C01F2 frequently asked

What is Mode-S code 4C01F2?
4C01F2 is an ICAO 24-bit transponder address. Allocated to Serbia. Assigned to YU-APS.
Where is Mode-S 4C01F2 registered?
Mode-S code 4C01F2 is allocated to Serbia (RS). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4C01F2 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 4C01F2, octal 23000762, decimal 4,981,234.
What flights does 4C01F2 operate?
Mode-S 4C01F2 has broadcast 8 distinct callsigns, including ASL15M, ASL63H, ASL53X, ASL53L, ASL51N.