sensors Mode-S transponder

506CDB

ICAO 24-bit transponder address · allocated to Slovenia

Currently assigned to S5-CNN · CESSNA 501 Citation 1SP

Hex
506CDB
Octal
24066333
Decimal
5,270,747
Country
SI
Tail
S5-CNN
Type
C501
No current signal · last broadcast 2d ago
Flights observed
1
Distinct callsigns
1
Country
SI
Last broadcast
2d ago

Last known position

Most recent position reported by Mode-S 506CDB.

Country allocation

The ICAO 24-bit address 506CDB falls within the block assigned to Slovenia (SI) by ICAO Annex 10, Volume III. Every aircraft registered in Slovenia 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
S5CNN - 1 2026-04-12

Recent flights last 1

DateFlightRouteTakeoffLandingDuration
2026-04-12 S5CNN - Apr 12, 17:15 UTCApr 12, 18:20 UTC1h 5m

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 S5-CNN page for operator, model, and routing details .

Mode-S 506CDB frequently asked

What is Mode-S code 506CDB?
506CDB is an ICAO 24-bit transponder address. Allocated to Slovenia. Assigned to S5-CNN.
Where is Mode-S 506CDB registered?
Mode-S code 506CDB is allocated to Slovenia (SI). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 506CDB broadcasting right now?
No active broadcast right now. Last signal was 2d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 506CDB, octal 24066333, decimal 5,270,747.
What flights does 506CDB operate?
Mode-S 506CDB has broadcast 1 distinct callsign, including S5CNN.