Apparatus

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sensors Mode-S transponder

4C01E1

ICAO 24-bit transponder address · allocated to Serbia

Currently assigned to YU-APB · AIRBUS A-319

Hex
4C01E1
Octal
23000741
Decimal
4,981,217
Country
RS
Tail
YU-APB
Type
A319
Broadcasting now · callsign ASL71G · 33,000 ft
Flights observed
170
Distinct callsigns
20
Country
RS
Last broadcast
3h ago

Current position

4C01E1 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 4C01E1 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
ASL95E - 5 2026-07-06
ASL86T - 5 2026-07-07
ASL58D Spurling Aviation 5 2026-07-03
ASL42A - 5 2026-06-18
ASL20K - 5 2026-06-18
ASL136 - 5 2026-07-01
ASL12X - 5 2026-07-03
ASL91K - 4 2026-07-07
ASL71G - 4 2026-06-27
ASL130 - 4 2026-07-05
ASL122 Spurling Aviation 4 2026-07-01
ASL94D - 3 2026-06-30
ASL81E Spurling Aviation 3 2026-06-21
ASL73B Spurling Aviation 3 2026-06-13
ASL54D - 3 2026-06-21
ASL19P - 3 2026-06-30
ASL124 Spurling Aviation 3 2026-06-12
ASL95T Spurling Aviation 2 2026-07-04
ASL91M - 2 2026-07-02
ASL86C - 2 2026-07-06

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-07 ASL86T BEG → CDG Jul 7, 04:55 UTCJul 7, 07:10 UTC2h 15m
2026-07-07 ASL91K TBS → BEG Jul 7, 00:00 UTCJul 7, 02:50 UTC2h 50m
2026-07-06 ASL95E - Jul 6, 11:55 UTCJul 6, 14:30 UTC2h 35m
2026-07-06 ASL86C - Jul 6, 07:50 UTCJul 6, 09:25 UTC1h 35m
2026-07-06 ASL64F - Jul 6, 04:55 UTCJul 6, 06:20 UTC1h 25m
2026-07-05 ASL44H - Jul 5, 18:45 UTCJul 5, 20:10 UTC1h 25m
2026-07-05 ASL86W BEG → BER Jul 5, 16:05 UTCJul 5, 17:35 UTC1h 30m
2026-07-05 ASL130 BEG → BEG Jul 5, 04:05 UTCJul 5, 10:50 UTC6h 45m
2026-07-04 ASL10P BEG → AMS Jul 4, 19:15 UTCJul 4, 20:45 UTC1h 30m
2026-07-04 ASL24E BEG → AHO Jul 4, 16:40 UTCJul 4, 18:10 UTC1h 30m
2026-07-04 ASL95T PMO → BEG Jul 4, 14:00 UTCJul 4, 15:20 UTC1h 20m
2026-07-04 ASL15F BEG → PMO Jul 4, 11:10 UTCJul 4, 12:30 UTC1h 20m
2026-07-04 ASL84J - Jul 4, 01:15 UTCJul 4, 03:35 UTC2h 20m
2026-07-03 ASL68F - Jul 3, 22:00 UTCJul 4, 00:00 UTC2h 0m
2026-07-03 ASL12X - Jul 3, 16:15 UTCJul 3, 17:05 UTC50m
2026-07-03 ASL58D INI → CGN Jul 3, 13:55 UTCJul 3, 14:30 UTC35m
2026-07-03 ASL18A DUS → BEG Jul 3, 07:50 UTCJul 3, 09:30 UTC1h 40m
2026-07-03 ASL54C BEG → DUS Jul 3, 04:40 UTCJul 3, 06:35 UTC1h 55m
2026-07-02 ASL188 BEG → KZN Jul 2, 18:45 UTCJul 3, 03:15 UTC8h 30m
2026-07-02 ASL12X - Jul 2, 14:20 UTCJul 2, 15:10 UTC50m
2026-07-02 ASL58D INI → CGN Jul 2, 11:35 UTCJul 2, 12:15 UTC40m
2026-07-02 ASL11A NCE → BEG Jul 2, 08:50 UTCJul 2, 10:25 UTC1h 35m
2026-07-02 ASL91M BEG → NCE Jul 2, 05:45 UTCJul 2, 07:20 UTC1h 35m
2026-07-01 ASL136 - Jul 1, 20:55 UTCJul 1, 22:55 UTC2h 0m
2026-07-01 ASL123 LED → BEG Jul 1, 15:55 UTCJul 1, 17:45 UTC1h 50m
2026-07-01 ASL122 BEG → LED Jul 1, 12:20 UTCJul 1, 14:45 UTC2h 25m
2026-07-01 ASL130 BEG → BEG Jul 1, 03:55 UTCJul 1, 11:05 UTC7h 10m
2026-06-30 ASL17H - Jun 30, 16:05 UTCJun 30, 19:35 UTC3h 30m
2026-06-30 ASL53X BEG → LIS Jun 30, 10:55 UTCJun 30, 14:15 UTC3h 20m
2026-06-30 ASL19P BER → BEG Jun 30, 07:35 UTCJun 30, 09:10 UTC1h 35m
2026-06-30 ASL94D BEG → BER Jun 30, 05:05 UTCJun 30, 06:25 UTC1h 20m
2026-06-29 ASL91K TBS → BEG Jun 29, 23:44 UTCJun 30, 02:20 UTC2h 36m
2026-06-29 ASL95E TBS → TBS Jun 29, 14:34 UTCJun 29, 14:39 UTC5m
2026-06-29 ASL95E - Jun 29, 11:55 UTCJun 29, 13:14 UTC1h 20m
2026-06-29 ASL19P BER → BEG Jun 29, 08:19 UTCJun 29, 09:50 UTC1h 30m
2026-06-29 ASL94D BEG → BER Jun 29, 05:15 UTCJun 29, 06:34 UTC1h 20m
2026-06-28 ASL16C - Jun 28, 14:34 UTCJun 28, 16:05 UTC1h 30m
2026-06-28 ASL25H BEG → JMK Jun 28, 10:55 UTCJun 28, 12:19 UTC1h 25m
2026-06-27 ASL136 BEG → BEG Jun 27, 20:09 UTCJun 28, 02:44 UTC6h 35m
2026-06-27 ASL122 BEG → LED Jun 27, 12:34 UTCJun 27, 18:24 UTC5h 50m
2026-06-27 ASL71G - Jun 27, 08:20 UTCJun 27, 10:14 UTC1h 55m
2026-06-27 ASL86T - Jun 27, 04:49 UTCJun 27, 06:54 UTC2h 5m
2026-06-26 ASL17H LIS → BEG Jun 26, 15:34 UTCJun 26, 18:44 UTC3h 10m
2026-06-26 ASL53X BEG → LIS Jun 26, 10:50 UTCJun 26, 14:15 UTC3h 25m
2026-06-26 ASL18A DUS → BEG Jun 26, 07:39 UTCJun 26, 09:20 UTC1h 40m
2026-06-26 ASL54C BEG → DUS Jun 26, 04:45 UTCJun 26, 06:35 UTC1h 50m
2026-06-25 ASL14C LIS → BEG Jun 25, 22:39 UTCJun 26, 02:05 UTC3h 25m
2026-06-25 ASL41G BEG → LIS Jun 25, 18:04 UTCJun 25, 21:35 UTC3h 30m
2026-06-25 ASL12X - Jun 25, 14:09 UTCJun 25, 14:55 UTC45m
2026-06-25 ASL58D INI → CGN Jun 25, 11:39 UTCJun 25, 12:30 UTC50m

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

Mode-S 4C01E1 frequently asked

What is Mode-S code 4C01E1?
4C01E1 is an ICAO 24-bit transponder address. Allocated to Serbia. Assigned to YU-APB.
Where is Mode-S 4C01E1 registered?
Mode-S code 4C01E1 is allocated to Serbia (RS). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4C01E1 broadcasting right now?
Yes. Mode-S 4C01E1 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4C01E1, octal 23000741, decimal 4,981,217.
What flights does 4C01E1 operate?
Mode-S 4C01E1 has broadcast 20 distinct callsigns, including ASL95E, ASL86T, ASL58D, ASL42A, ASL20K.