Apparatus

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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
No current signal · last broadcast 8h ago
Flights observed
457
Distinct callsigns
20
Country
RS
Last broadcast
8h 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 20 distinct

Callsign Airline Flights Last seen
ASL12H - 15 2026-07-07
ASL10A Spurling Aviation 13 2026-07-07
ASL427 - 11 2026-07-14
ASL426 - 11 2026-07-13
ASL82Y - 10 2026-07-10
ASL65W - 10 2026-07-10
ASL15A - 10 2026-07-13
ASL95E - 9 2026-07-08
ASL57F - 9 2026-07-13
ASL41G - 9 2026-07-09
ASL14C - 9 2026-07-09
ASL96D - 8 2026-06-28
ASL91K - 8 2026-07-08
ASL64R - 8 2026-06-28
ASL71G - 7 2026-07-02
ASL49U - 7 2026-06-30
ASL48X - 7 2026-06-29
ASL45X Spurling Aviation 7 2026-06-30
ASL43N - 7 2026-07-13
ASL93X - 6 2026-06-30

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
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
2026-07-12 ASL90F BEG → ZRH Jul 12, 16:15 UTCJul 12, 17:50 UTC1h 35m
2026-07-12 ASL16C - Jul 12, 13:20 UTCJul 12, 14:55 UTC1h 35m
2026-07-12 ASL25H - Jul 12, 10:30 UTCJul 12, 12:01 UTC1h 30m
2026-07-12 ASL85D - Jul 12, 06:01 UTCJul 12, 07:10 UTC1h 10m
2026-07-12 ASL38F - Jul 12, 03:40 UTCJul 12, 04:55 UTC1h 15m
2026-07-11 ASL93N RHO → BEG Jul 11, 14:45 UTCJul 11, 16:30 UTC1h 45m
2026-07-11 ASL36V BEG → RHO Jul 11, 12:00 UTCJul 11, 13:40 UTC1h 40m
2026-07-11 ASL66K - Jul 11, 08:20 UTCJul 11, 10:00 UTC1h 40m
2026-07-11 ASL14B BEG → CPH Jul 11, 04:50 UTCJul 11, 06:55 UTC2h 5m
2026-07-10 ASL65W ARN → BEG Jul 10, 21:00 UTCJul 10, 23:10 UTC2h 10m
2026-07-10 ASL82Y BEG → ARN Jul 10, 16:50 UTCJul 10, 19:25 UTC2h 35m
2026-07-09 ASL14C LIS → BEG Jul 9, 22:40 UTCJul 10, 01:55 UTC3h 15m
2026-07-09 ASL41G BEG → LIS Jul 9, 17:45 UTCJul 9, 21:05 UTC3h 20m
2026-07-09 ASL423 - Jul 9, 14:30 UTCJul 9, 15:40 UTC1h 10m
2026-07-09 ASL422 - Jul 9, 11:40 UTCJul 9, 12:50 UTC1h 10m
2026-07-09 ASL16G MXP → BEG Jul 9, 07:40 UTCJul 9, 09:00 UTC1h 20m
2026-07-09 ASL58V BEG → MXP Jul 9, 04:55 UTCJul 9, 06:25 UTC1h 30m
2026-07-09 ASL84J - Jul 9, 01:20 UTCJul 9, 03:35 UTC2h 15m
2026-07-08 ASL68F - Jul 8, 22:00 UTCJul 9, 00:05 UTC2h 5m
2026-07-08 ASL27L DBV → BEG Jul 8, 16:30 UTCJul 8, 17:10 UTC40m
2026-07-08 ASL90A BEG → DBV Jul 8, 14:50 UTCJul 8, 15:25 UTC35m
2026-07-08 ASL91K TBS → BEG Jul 8, 10:40 UTCJul 8, 13:35 UTC2h 55m
2026-07-08 ASL95E - Jul 8, 09:05 UTCJul 8, 09:25 UTC20m
2026-07-08 ASL95E - Jul 8, 06:45 UTCJul 8, 07:55 UTC1h 10m
2026-07-07 ASL10A BEG → ZRH Jul 7, 12:50 UTCJul 7, 15:05 UTC2h 15m
2026-07-07 ASL12H BEG → LHR Jul 7, 09:05 UTCJul 7, 11:35 UTC2h 30m
2026-07-07 ASL43B BEG → HAM Jul 7, 06:40 UTCJul 7, 07:40 UTC1h 0m
2026-07-07 ASL60A - Jul 7, 04:15 UTCJul 7, 05:15 UTC1h 0m
2026-07-06 ASL11B BCN → BEG Jul 6, 19:40 UTCJul 6, 21:45 UTC2h 5m
2026-07-06 ASL73J BEG → BCN Jul 6, 16:00 UTCJul 6, 18:15 UTC2h 15m
2026-07-06 ASL86U - Jul 6, 14:05 UTCJul 6, 14:40 UTC35m
2026-07-06 ASL87A - Jul 6, 12:15 UTCJul 6, 12:50 UTC35m
2026-07-06 ASL38K AMS → BEG Jul 6, 09:05 UTCJul 6, 11:00 UTC1h 55m
2026-07-06 ASL26G BEG → AMS Jul 6, 05:05 UTCJul 6, 07:15 UTC2h 10m
2026-07-05 ASL57T VLC → BEG Jul 5, 19:35 UTCJul 5, 22:00 UTC2h 25m
2026-07-05 ASL67A ZAG → BEG Jul 5, 15:35 UTCJul 5, 18:15 UTC2h 40m
2026-07-05 ASL99L - Jul 5, 10:10 UTCJul 5, 10:35 UTC25m
2026-07-05 ASL52N BEG → TIV Jul 5, 08:25 UTCJul 5, 08:45 UTC20m
2026-07-05 ASL15A - Jul 5, 06:25 UTCJul 5, 06:50 UTC25m
2026-07-05 ASL57F - Jul 5, 04:45 UTCJul 5, 05:05 UTC20m
2026-07-04 ASL14C LIS → BEG Jul 4, 23:05 UTCJul 5, 02:20 UTC3h 15m

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 8h 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 20 distinct callsigns, including ASL12H, ASL10A, ASL427, ASL426, ASL82Y.