sensors Mode-S transponder

4C01E4

ICAO 24-bit transponder address · allocated to Serbia

Currently assigned to YU-APE · AIRBUS A-319

Hex
4C01E4
Octal
23000744
Decimal
4,981,220
Country
RS
Tail
YU-APE
Type
A319
Photo of YU-APE
No current signal · last broadcast 16h ago
Flights observed
13
Distinct callsigns
8
Country
RS
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S 4C01E4.

Country allocation

The ICAO 24-bit address 4C01E4 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
ASL43N - 3 2026-04-13
ASL48X Spurling Aviation 2 2026-04-13
ASL14G - 2 2026-04-13
ASL12H - 2 2026-04-14
ASL93X - 1 2026-04-13
ASL68F - 1 2026-04-13
ASL38M - 1 2026-04-13
ASL37R - 1 2026-04-13

Recent flights last 13

DateFlightRouteTakeoffLandingDuration
2026-04-14 ASL12H - Apr 14, 09:10 UTCApr 14, 11:05 UTC1h 55m
2026-04-14 ASL12H - Apr 14, 08:45 UTCApr 14, 09:05 UTC20m
2026-04-13 ASL68F - Apr 13, 21:45 UTCApr 13, 23:45 UTC2h 0m
2026-04-13 ASL43N - Apr 13, 19:50 UTCApr 13, 20:40 UTC50m
2026-04-13 ASL43N - Apr 13, 19:20 UTCApr 13, 20:10 UTC50m
2026-04-13 ASL14G BEG → MXP Apr 13, 16:25 UTCApr 13, 17:55 UTC1h 30m
2026-04-13 ASL37R - Apr 13, 13:25 UTCApr 13, 13:50 UTC25m
2026-04-13 ASL93X - Apr 13, 11:40 UTCApr 13, 12:00 UTC20m
2026-04-13 ASL48X LCA → BEG Apr 13, 08:20 UTCApr 13, 10:35 UTC2h 15m
2026-04-13 ASL48X LCA → BEG Apr 13, 08:10 UTCApr 13, 10:35 UTC2h 25m
2026-04-13 ASL38M - Apr 13, 05:00 UTCApr 13, 07:00 UTC2h 0m
2026-04-12 ASL43N - Apr 12, 19:15 UTCApr 12, 20:15 UTC1h 0m
2026-04-12 ASL14G - Apr 12, 17:15 UTCApr 12, 17:50 UTC35m

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

Mode-S 4C01E4 frequently asked

What is Mode-S code 4C01E4?
4C01E4 is an ICAO 24-bit transponder address. Allocated to Serbia. Assigned to YU-APE.
Where is Mode-S 4C01E4 registered?
Mode-S code 4C01E4 is allocated to Serbia (RS). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4C01E4 broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4C01E4, octal 23000744, decimal 4,981,220.
What flights does 4C01E4 operate?
Mode-S 4C01E4 has broadcast 8 distinct callsigns, including ASL43N, ASL48X, ASL14G, ASL12H, ASL93X.