Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

4C0243

ICAO 24-bit transponder address · allocated to Serbia

Currently assigned to YU-ASD · ATR-72-600

Hex
4C0243
Octal
23001103
Decimal
4,981,315
Country
RS
Tail
YU-ASD
Type
AT76
No current signal · last broadcast 20m ago
Flights observed
478
Distinct callsigns
20
Country
RS
Last broadcast
20m ago

Last known position

Most recent position reported by Mode-S 4C0243.

Country allocation

The ICAO 24-bit address 4C0243 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
ASL72L Spurling Aviation 15 2026-07-13
ASL10N Spurling Aviation 15 2026-07-13
ASL45T Spurling Aviation 14 2026-07-06
ASL37Z - 14 2026-07-06
ASL31Q - 13 2026-07-12
ASL81C Spurling Aviation 12 2026-07-07
ASL80A - 12 2026-07-07
ASL49H Spurling Aviation 12 2026-07-07
ASL44Q - 12 2026-07-07
ASL77L - 10 2026-07-12
ASL79Y Spurling Aviation 9 2026-06-30
ASL47P Spurling Aviation 9 2026-06-23
ASL26X Spurling Aviation 9 2026-06-23
ASL74K - 8 2026-07-08
ASL70Z - 8 2026-07-12
ASL52D - 8 2026-07-13
ASL40Y - 8 2026-07-08
ASL33K Spurling Aviation 8 2026-06-30
ASL96B - 7 2026-07-09
ASL78U - 7 2026-07-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 ASL72Q - Jul 14, 11:40 UTCJul 14, 12:40 UTC1h 0m
2026-07-13 ASL10N LJU → BEG Jul 13, 18:55 UTCJul 13, 20:00 UTC1h 5m
2026-07-13 ASL72L BEG → TIA Jul 13, 16:50 UTCJul 13, 18:15 UTC1h 25m
2026-07-13 ASL88A FRA → BEG Jul 13, 13:40 UTCJul 13, 14:50 UTC1h 10m
2026-07-13 ASL16F INI → CGN Jul 13, 11:25 UTCJul 13, 12:15 UTC50m
2026-07-13 ASL78U - Jul 13, 07:45 UTCJul 13, 09:35 UTC1h 50m
2026-07-13 ASL18R BEG → PRG Jul 13, 04:55 UTCJul 13, 06:45 UTC1h 50m
2026-07-13 ASL52D - Jul 13, 01:25 UTCJul 13, 02:55 UTC1h 30m
2026-07-12 ASL70Z - Jul 12, 23:05 UTCJul 13, 00:25 UTC1h 20m
2026-07-12 ASL77J - Jul 12, 19:15 UTCJul 12, 21:10 UTC1h 55m
2026-07-12 ASL48D LIS → BEG Jul 12, 16:25 UTCJul 12, 18:15 UTC1h 50m
2026-07-12 ASL51D ZAG → BEG Jul 12, 13:15 UTCJul 12, 14:10 UTC55m
2026-07-12 ASL30J BEG → ZAG Jul 12, 11:25 UTCJul 12, 12:20 UTC55m
2026-07-12 ASL31Q - Jul 12, 07:20 UTCJul 12, 08:25 UTC1h 5m
2026-07-12 ASL77L - Jul 12, 05:25 UTCJul 12, 06:35 UTC1h 10m
2026-07-12 ASL33J - Jul 12, 02:01 UTCJul 12, 02:35 UTC35m
2026-07-11 ASL47G - Jul 11, 23:10 UTCJul 11, 23:50 UTC40m
2026-07-11 ASL61J BEG → TIV Jul 11, 13:05 UTCJul 11, 14:05 UTC1h 0m
2026-07-11 ASL77B BEG → VIE Jul 11, 10:55 UTCJul 11, 12:15 UTC1h 20m
2026-07-11 ASL78U PRG → BEG Jul 11, 07:55 UTCJul 11, 09:30 UTC1h 35m
2026-07-11 ASL18R BEG → PRG Jul 11, 04:55 UTCJul 11, 06:50 UTC1h 55m
2026-07-11 ASL52D - Jul 11, 01:20 UTCJul 11, 02:50 UTC1h 30m
2026-07-10 ASL70Z - Jul 10, 22:45 UTCJul 11, 00:00 UTC1h 15m
2026-07-10 ASL51D ZAG → BEG Jul 10, 14:10 UTCJul 10, 15:05 UTC55m
2026-07-10 ASL30J BEG → ZAG Jul 10, 12:20 UTCJul 10, 13:15 UTC55m
2026-07-10 ASL19N - Jul 10, 08:10 UTCJul 10, 08:45 UTC35m
2026-07-10 ASL23K - Jul 10, 06:05 UTCJul 10, 06:35 UTC30m
2026-07-10 ASL52D - Jul 10, 01:20 UTCJul 10, 02:55 UTC1h 35m
2026-07-09 ASL70Z - Jul 9, 22:45 UTCJul 10, 00:05 UTC1h 20m
2026-07-09 ASL97E BUD → BEG Jul 9, 13:55 UTCJul 9, 14:50 UTC55m
2026-07-09 ASL72Q BEG → BUD Jul 9, 12:15 UTCJul 9, 13:05 UTC50m
2026-07-09 ASL10Q BUD → BEG Jul 9, 10:05 UTCJul 9, 10:55 UTC50m
2026-07-09 ASL34H BEG → BUD Jul 9, 08:05 UTCJul 9, 08:55 UTC50m
2026-07-09 ASL96B - Jul 9, 02:20 UTCJul 9, 03:05 UTC45m
2026-07-08 ASL59D - Jul 8, 23:30 UTCJul 9, 00:10 UTC40m
2026-07-08 ASL40Y - Jul 8, 13:00 UTCJul 8, 14:10 UTC1h 10m
2026-07-08 ASL74K - Jul 8, 10:35 UTCJul 8, 11:55 UTC1h 20m
2026-07-08 ASL31Q - Jul 8, 07:30 UTCJul 8, 08:40 UTC1h 10m
2026-07-08 ASL77L BEG → LJU Jul 8, 05:20 UTCJul 8, 06:40 UTC1h 20m
2026-07-08 ASL33J - Jul 8, 02:10 UTCJul 8, 02:40 UTC30m
2026-07-07 ASL47G - Jul 7, 22:55 UTCJul 7, 23:30 UTC35m
2026-07-07 ASL49H ZRH → BEG Jul 7, 13:15 UTCJul 7, 13:45 UTC30m
2026-07-07 ASL81C BEG → SJJ Jul 7, 11:50 UTCJul 7, 12:25 UTC35m
2026-07-07 ASL44Q - Jul 7, 07:30 UTCJul 7, 08:30 UTC1h 0m
2026-07-07 ASL80A BEG → VIE Jul 7, 05:30 UTCJul 7, 06:40 UTC1h 10m
2026-07-06 ASL37Z VIE → BEG Jul 6, 18:55 UTCJul 6, 19:55 UTC1h 0m
2026-07-06 ASL45T BEG → VIE Jul 6, 16:45 UTCJul 6, 17:55 UTC1h 10m
2026-07-06 ASL32P BEG → LCA Jul 6, 14:35 UTCJul 6, 15:10 UTC35m
2026-07-06 ASL38Y - Jul 6, 12:05 UTCJul 6, 12:40 UTC35m
2026-07-06 ASL341 - Jul 6, 08:35 UTCJul 6, 10:25 UTC1h 50m

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

Mode-S 4C0243 frequently asked

What is Mode-S code 4C0243?
4C0243 is an ICAO 24-bit transponder address. Allocated to Serbia. Assigned to YU-ASD.
Where is Mode-S 4C0243 registered?
Mode-S code 4C0243 is allocated to Serbia (RS). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4C0243 broadcasting right now?
No active broadcast right now. Last signal was 20m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4C0243, octal 23001103, decimal 4,981,315.
What flights does 4C0243 operate?
Mode-S 4C0243 has broadcast 20 distinct callsigns, including ASL72L, ASL10N, ASL45T, ASL37Z, ASL31Q.