sensors Mode-S transponder

4C01E5

ICAO 24-bit transponder address · allocated to Serbia

Currently assigned to YU-APF · AIRBUS A-319

Hex
4C01E5
Octal
23000745
Decimal
4,981,221
Country
RS
Tail
YU-APF
Type
A319
Photo of YU-APF
No current signal · last broadcast 13h ago
Flights observed
15
Distinct callsigns
11
Country
RS
Last broadcast
13h ago

Last known position

Most recent position reported by Mode-S 4C01E5.

Country allocation

The ICAO 24-bit address 4C01E5 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 11 distinct

Callsign Airline Flights Last seen
ASL73J - 3 2026-04-13
ASL18F - 2 2026-04-14
ASL11B - 2 2026-04-13
ASL96K - 1 2026-04-13
ASL87A - 1 2026-04-13
ASL86U - 1 2026-04-13
ASL82Y - 1 2026-04-12
ASL78N - 1 2026-04-14
ASL76H Spurling Aviation 1 2026-04-13
ASL65W - 1 2026-04-12
ASL37J - 1 2026-04-13

Recent flights last 15

DateFlightRouteTakeoffLandingDuration
2026-04-14 ASL18F - Apr 14, 09:10 UTCApr 14, 10:05 UTC55m
2026-04-14 ASL18F - Apr 14, 08:20 UTCApr 14, 09:05 UTC45m
2026-04-14 ASL78N - Apr 14, 05:15 UTCApr 14, 07:05 UTC1h 50m
2026-04-13 ASL37J - Apr 13, 22:25 UTCApr 13, 22:40 UTC15m
2026-04-13 ASL11B - Apr 13, 19:50 UTCApr 13, 21:00 UTC1h 10m
2026-04-13 ASL11B - Apr 13, 18:55 UTCApr 13, 20:10 UTC1h 15m
2026-04-13 ASL73J - Apr 13, 16:15 UTCApr 13, 17:45 UTC1h 30m
2026-04-13 ASL73J - Apr 13, 15:50 UTCApr 13, 17:45 UTC1h 55m
2026-04-13 ASL73J - Apr 13, 15:25 UTCApr 13, 16:15 UTC50m
2026-04-13 ASL86U - Apr 13, 13:30 UTCApr 13, 14:00 UTC30m
2026-04-13 ASL87A - Apr 13, 11:45 UTCApr 13, 12:10 UTC25m
2026-04-13 ASL76H ARN → BEG Apr 13, 08:20 UTCApr 13, 10:30 UTC2h 10m
2026-04-13 ASL96K BEG → ARN Apr 13, 04:50 UTCApr 13, 07:10 UTC2h 20m
2026-04-12 ASL65W - Apr 12, 19:05 UTCApr 12, 20:15 UTC1h 10m
2026-04-12 ASL82Y - Apr 12, 17:15 UTCApr 12, 18:00 UTC45m

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

Mode-S 4C01E5 frequently asked

What is Mode-S code 4C01E5?
4C01E5 is an ICAO 24-bit transponder address. Allocated to Serbia. Assigned to YU-APF.
Where is Mode-S 4C01E5 registered?
Mode-S code 4C01E5 is allocated to Serbia (RS). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4C01E5 broadcasting right now?
No active broadcast right now. Last signal was 13h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4C01E5, octal 23000745, decimal 4,981,221.
What flights does 4C01E5 operate?
Mode-S 4C01E5 has broadcast 11 distinct callsigns, including ASL73J, ASL18F, ASL11B, ASL96K, ASL87A.