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
Broadcasting now · callsign ASL30L · 1,700 ft
Flights observed
498
Distinct callsigns
20
Country
RS
Last broadcast
Jul 26, 02:30 UTC

Current position

4C01E4 is currently broadcasting. Map zoomed to live position.

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 20 distinct

Callsign Airline Flights Last seen
ASL12H Spurling Aviation 17 2026-07-25
ASL10A Spurling Aviation 15 2026-07-25
ASL95E - 12 2026-07-19
ASL82Y Spurling Aviation 12 2026-07-23
ASL65W Spurling Aviation 12 2026-07-23
ASL427 - 11 2026-07-14
ASL426 - 11 2026-07-13
ASL91K - 10 2026-07-19
ASL41G - 10 2026-07-25
ASL15A - 10 2026-07-13
ASL14C Spurling Aviation 10 2026-07-25
ASL57F - 9 2026-07-13
ASL96D - 8 2026-06-28
ASL64R - 8 2026-06-28
ASL93X - 7 2026-07-23
ASL71G - 7 2026-07-02
ASL68F Spurling Aviation 7 2026-07-24
ASL49U - 7 2026-06-30
ASL48X - 7 2026-06-29
ASL45X Spurling Aviation 7 2026-06-30

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-25 ASL14C BEG → OPO Jul 25, 23:25 UTCJul 26, 02:25 UTC3h 0m
2026-07-25 ASL41G - Jul 25, 18:10 UTCJul 25, 22:00 UTC3h 50m
2026-07-25 ASL10A BEG → ZRH Jul 25, 12:40 UTCJul 25, 15:00 UTC2h 20m
2026-07-25 ASL12H BEG → LHR Jul 25, 08:35 UTCJul 25, 11:05 UTC2h 30m
2026-07-25 ASL84J LCA → BEG Jul 25, 01:20 UTCJul 25, 03:45 UTC2h 25m
2026-07-24 ASL68F CGN → INI Jul 24, 22:00 UTCJul 25, 00:05 UTC2h 5m
2026-07-24 ASL10A BEG → ZRH Jul 24, 13:15 UTCJul 24, 15:30 UTC2h 15m
2026-07-24 ASL12H BEG → LHR Jul 24, 08:35 UTCJul 24, 11:10 UTC2h 35m
2026-07-24 ASL9731 - Jul 24, 05:50 UTCJul 24, 07:25 UTC1h 35m
2026-07-24 ASL9730 - Jul 24, 03:10 UTCJul 24, 04:40 UTC1h 30m
2026-07-23 ASL65W ARN → BEG Jul 23, 19:20 UTCJul 23, 21:25 UTC2h 5m
2026-07-23 ASL82Y BEG → ARN Jul 23, 15:45 UTCJul 23, 18:05 UTC2h 20m
2026-07-23 ASL37R - Jul 23, 14:00 UTCJul 23, 14:25 UTC25m
2026-07-23 ASL93X - Jul 23, 12:20 UTCJul 23, 12:45 UTC25m
2026-07-19 ASL65W ARN → BEG Jul 19, 19:55 UTCJul 19, 22:15 UTC2h 20m
2026-07-19 ASL82Y BEG → ARN Jul 19, 15:40 UTCJul 19, 17:45 UTC2h 5m
2026-07-19 ASL91K TBS → BEG Jul 19, 10:35 UTCJul 19, 13:25 UTC2h 50m
2026-07-19 ASL95E BEG → TBS Jul 19, 06:45 UTCJul 19, 09:25 UTC2h 40m
2026-07-19 ASL53B LIS → BEG Jul 19, 03:05 UTCJul 19, 03:30 UTC25m
2026-07-18 ASL18F BEG → TIA Jul 18, 21:55 UTCJul 18, 23:30 UTC1h 35m
2026-07-18 ASL78N - Jul 18, 18:50 UTCJul 18, 20:55 UTC2h 5m
2026-07-18 ASL1425 IST → INI Jul 18, 16:10 UTCJul 18, 17:10 UTC1h 0m
2026-07-18 ASL1424 INI → IST Jul 18, 13:50 UTCJul 18, 14:45 UTC55m
2026-07-18 ASL41E CGN → INI Jul 18, 10:55 UTCJul 18, 12:35 UTC1h 40m
2026-07-18 ASL56D - Jul 18, 07:25 UTCJul 18, 09:30 UTC2h 5m
2026-07-18 ASL72M - Jul 18, 06:05 UTCJul 18, 06:25 UTC20m
2026-07-18 ASL44F INI → TIV Jul 18, 04:25 UTCJul 18, 04:45 UTC20m
2026-07-17 ASL37J - Jul 17, 23:05 UTCJul 17, 23:25 UTC20m
2026-07-17 ASL11B BCN → BEG Jul 17, 19:49 UTCJul 17, 21:55 UTC2h 5m
2026-07-17 ASL73J - Jul 17, 16:10 UTCJul 17, 18:29 UTC2h 20m
2026-07-17 ASL86U - Jul 17, 14:24 UTCJul 17, 15:05 UTC40m
2026-07-17 ASL87A - Jul 17, 11:55 UTCJul 17, 12:25 UTC30m
2026-07-17 ASL51N BCN → BEG Jul 17, 08:40 UTCJul 17, 10:40 UTC2h 0m
2026-07-17 ASL63H BEG → BCN Jul 17, 04:49 UTCJul 17, 07:14 UTC2h 25m
2026-07-17 ASL91K TBS → BEG Jul 17, 00:10 UTCJul 17, 03:05 UTC2h 55m
2026-07-16 ASL95E - Jul 16, 14:00 UTCJul 16, 14:20 UTC20m
2026-07-16 ASL95E - Jul 16, 11:45 UTCJul 16, 13:05 UTC1h 20m
2026-07-16 ASL11A NCE → BEG Jul 16, 08:35 UTCJul 16, 10:04 UTC1h 30m
2026-07-16 ASL91M BEG → NCE Jul 16, 05:20 UTCJul 16, 07:10 UTC1h 50m
2026-07-15 ASL88B STR → BEG Jul 15, 20:35 UTCJul 15, 21:50 UTC1h 15m
2026-07-15 ASL99K BEG → STR Jul 15, 17:20 UTCJul 15, 18:50 UTC1h 30m
2026-07-14 ASL427 - Jul 14, 01:45 UTCJul 14, 03:00 UTC1h 15m
2026-07-13 ASL426 - Jul 13, 23:10 UTCJul 14, 00:20 UTC1h 10m
2026-07-13 ASL43N MXP → BEG Jul 13, 20:00 UTCJul 13, 21:15 UTC1h 15m
2026-07-13 ASL14G BEG → LHR Jul 13, 16:40 UTCJul 13, 18:05 UTC1h 25m
2026-07-13 ASL15A - Jul 13, 06:35 UTCJul 13, 07:01 UTC25m
2026-07-13 ASL57F - Jul 13, 05:05 UTCJul 13, 05:25 UTC20m
2026-07-13 ASL84J - Jul 13, 01:20 UTCJul 13, 03:45 UTC2h 25m
2026-07-12 ASL68F - Jul 12, 22:10 UTCJul 13, 00:15 UTC2h 5m
2026-07-12 ASL98C ZRH → BEG Jul 12, 19:10 UTCJul 12, 20:35 UTC1h 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-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?
Yes. Mode-S 4C01E4 is currently airborne.
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 20 distinct callsigns, including ASL12H, ASL10A, ASL95E, ASL82Y, ASL65W.