sensors Mode-S transponder

4C31E2

ICAO 24-bit transponder address · allocated to Serbia

Currently assigned to YU-MPC · CESSNA 525 Citation M2

Hex
4C31E2
Octal
23030742
Decimal
4,993,506
Country
RS
Tail
YU-MPC
Type
C25M
No current signal · last broadcast 1d ago
Flights observed
3
Distinct callsigns
1
Country
RS
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 4C31E2.

Country allocation

The ICAO 24-bit address 4C31E2 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 1 distinct

Callsign Airline Flights Last seen
MPC001 - 3 2026-04-13

Recent flights last 3

DateFlightRouteTakeoffLandingDuration
2026-04-13 MPC001 - Apr 13, 19:50 UTCApr 13, 20:50 UTC1h 0m
2026-04-13 MPC001 - Apr 13, 19:20 UTCApr 13, 20:10 UTC50m
2026-04-13 MPC001 ATH → BEG Apr 13, 08:30 UTCApr 13, 09:55 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-MPC page for operator, model, and routing details .

Mode-S 4C31E2 frequently asked

What is Mode-S code 4C31E2?
4C31E2 is an ICAO 24-bit transponder address. Allocated to Serbia. Assigned to YU-MPC.
Where is Mode-S 4C31E2 registered?
Mode-S code 4C31E2 is allocated to Serbia (RS). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4C31E2 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4C31E2, octal 23030742, decimal 4,993,506.
What flights does 4C31E2 operate?
Mode-S 4C31E2 has broadcast 1 distinct callsign, including MPC001.