sensors Mode-S transponder

4C01E7

ICAO 24-bit transponder address · allocated to Serbia

Currently assigned to YU-APH · AIRBUS A-320

Hex
4C01E7
Octal
23000747
Decimal
4,981,223
Country
RS
Tail
YU-APH
Type
A320
Photo of YU-APH
No current signal · last broadcast 23h ago
Flights observed
6
Distinct callsigns
6
Country
RS
Last broadcast
23h ago

Last known position

Most recent position reported by Mode-S 4C01E7.

Country allocation

The ICAO 24-bit address 4C01E7 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 6 distinct

Callsign Airline Flights Last seen
ASL86T - 1 2026-04-13
ASL81E - 1 2026-04-12
ASL71G Spurling Aviation 1 2026-04-13
ASL54D - 1 2026-04-12
ASL135 - 1 2026-04-13
ASL134 - 1 2026-04-13

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-13 ASL135 - Apr 13, 22:25 UTCApr 13, 23:40 UTC1h 15m
2026-04-13 ASL134 - Apr 13, 17:00 UTCApr 13, 19:20 UTC2h 20m
2026-04-13 ASL71G CDG → BEG Apr 13, 08:45 UTCApr 13, 10:50 UTC2h 5m
2026-04-13 ASL86T - Apr 13, 04:55 UTCApr 13, 06:55 UTC2h 0m
2026-04-12 ASL54D - Apr 12, 19:05 UTCApr 12, 20:10 UTC1h 5m
2026-04-12 ASL81E - Apr 12, 17:15 UTCApr 12, 17:45 UTC30m

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

Mode-S 4C01E7 frequently asked

What is Mode-S code 4C01E7?
4C01E7 is an ICAO 24-bit transponder address. Allocated to Serbia. Assigned to YU-APH.
Where is Mode-S 4C01E7 registered?
Mode-S code 4C01E7 is allocated to Serbia (RS). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4C01E7 broadcasting right now?
No active broadcast right now. Last signal was 23h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4C01E7, octal 23000747, decimal 4,981,223.
What flights does 4C01E7 operate?
Mode-S 4C01E7 has broadcast 6 distinct callsigns, including ASL86T, ASL81E, ASL71G, ASL54D, ASL135.