sensors Mode-S transponder

4C01F3

ICAO 24-bit transponder address · allocated to Serbia

Currently assigned to YU-APT · AIRBUS A-320

Hex
4C01F3
Octal
23000763
Decimal
4,981,235
Country
RS
Tail
YU-APT
Type
A320
No current signal · last broadcast 3h ago
Flights observed
29
Distinct callsigns
8
Country
RS
Last broadcast
3h ago

Last known position

Most recent position reported by Mode-S 4C01F3.

Country allocation

The ICAO 24-bit address 4C01F3 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
ASL133 - 5 2026-04-18
ASL132 Spurling Aviation 5 2026-04-18
ASL63H Spurling Aviation 4 2026-04-17
ASL51N Spurling Aviation 4 2026-04-17
ASL134 - 4 2026-04-17
ASL27E - 3 2026-04-15
ASL71A Spurling Aviation 2 2026-04-15
ASL135 Spurling Aviation 2 2026-04-17

Recent flights last 29

DateFlightRouteTakeoffLandingDuration
2026-04-18 ASL133 SVO → BEG Apr 18, 17:10 UTCApr 18, 19:40 UTC2h 30m
2026-04-18 ASL132 BEG → SVO Apr 18, 12:45 UTCApr 18, 15:35 UTC2h 50m
2026-04-17 ASL135 SVO → BEG Apr 17, 23:25 UTCApr 17, 23:45 UTC20m
2026-04-17 ASL135 SVO → BEG Apr 17, 22:45 UTCApr 17, 23:20 UTC35m
2026-04-17 ASL134 - Apr 17, 17:25 UTCApr 17, 19:20 UTC1h 55m
2026-04-17 ASL134 - Apr 17, 17:00 UTCApr 17, 17:15 UTC15m
2026-04-17 ASL51N BEG → BEG Apr 17, 09:20 UTCApr 17, 11:00 UTC1h 40m
2026-04-17 ASL51N BEG → BEG Apr 17, 08:55 UTCApr 17, 09:15 UTC20m
2026-04-17 ASL63H BEG → ZRH Apr 17, 05:20 UTCApr 17, 07:10 UTC1h 50m
2026-04-17 ASL63H BEG → ZRH Apr 17, 04:50 UTCApr 17, 05:15 UTC25m
2026-04-16 ASL133 - Apr 16, 19:15 UTCApr 16, 19:45 UTC30m
2026-04-16 ASL133 - Apr 16, 18:05 UTCApr 16, 19:10 UTC1h 5m
2026-04-16 ASL132 BEG → SVO Apr 16, 13:15 UTCApr 16, 15:05 UTC1h 50m
2026-04-16 ASL132 BEG → SVO Apr 16, 12:49 UTCApr 16, 13:05 UTC15m
2026-04-16 ASL51N BEG → BEG Apr 16, 09:10 UTCApr 16, 10:40 UTC1h 30m
2026-04-16 ASL51N BEG → BEG Apr 16, 08:19 UTCApr 16, 09:05 UTC45m
2026-04-16 ASL63H BEG → ZRH Apr 16, 05:09 UTCApr 16, 06:55 UTC1h 45m
2026-04-16 ASL63H BEG → ZRH Apr 16, 04:40 UTCApr 16, 05:05 UTC25m
2026-04-15 ASL134 - Apr 15, 19:05 UTCApr 15, 19:40 UTC35m
2026-04-15 ASL134 - Apr 15, 17:05 UTCApr 15, 19:00 UTC1h 55m
2026-04-15 ASL71A BEG → AMS Apr 15, 13:01 UTCApr 15, 13:55 UTC55m
2026-04-15 ASL71A BEG → AMS Apr 15, 11:10 UTCApr 15, 12:55 UTC1h 45m
2026-04-15 ASL27E - Apr 15, 09:00 UTCApr 15, 09:20 UTC20m
2026-04-15 ASL27E - Apr 15, 07:01 UTCApr 15, 08:55 UTC1h 55m
2026-04-15 ASL27E - Apr 15, 06:20 UTCApr 15, 06:55 UTC35m
2026-04-14 ASL133 - Apr 14, 18:55 UTCApr 14, 20:10 UTC1h 15m
2026-04-14 ASL133 - Apr 14, 17:30 UTCApr 14, 18:45 UTC1h 15m
2026-04-14 ASL132 BEG → SVO Apr 14, 14:50 UTCApr 14, 15:15 UTC25m
2026-04-14 ASL132 BEG → SVO Apr 14, 13:10 UTCApr 14, 14:45 UTC1h 35m

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

Mode-S 4C01F3 frequently asked

What is Mode-S code 4C01F3?
4C01F3 is an ICAO 24-bit transponder address. Allocated to Serbia. Assigned to YU-APT.
Where is Mode-S 4C01F3 registered?
Mode-S code 4C01F3 is allocated to Serbia (RS). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4C01F3 broadcasting right now?
No active broadcast right now. Last signal was 3h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4C01F3, octal 23000763, decimal 4,981,235.
What flights does 4C01F3 operate?
Mode-S 4C01F3 has broadcast 8 distinct callsigns, including ASL133, ASL132, ASL63H, ASL51N, ASL134.