sensors Mode-S transponder

4CAA6A

ICAO 24-bit transponder address · allocated to Ireland

Hex
4CAA6A
Octal
23125152
Decimal
5,024,362
Country
IE
No current signal · last broadcast Jun 11, 14:50 UTC
Flights observed
1
Distinct callsigns
1
Country
IE
Last broadcast
Jun 11, 14:50 UTC

Last known position

Most recent position reported by Mode-S 4CAA6A.

Country allocation

The ICAO 24-bit address 4CAA6A falls within the block assigned to Ireland (IE) by ICAO Annex 10, Volume III. Every aircraft registered in Ireland 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
RYR18ZU Ryanair 1 2026-06-11

Recent flights last 1

DateFlightRouteTakeoffLandingDuration
2026-06-11 RYR18ZU PMI → BOH Jun 11, 14:40 UTCJun 11, 14:50 UTC10m

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.

Mode-S 4CAA6A frequently asked

What is Mode-S code 4CAA6A?
4CAA6A is an ICAO 24-bit transponder address. Allocated to Ireland.
Where is Mode-S 4CAA6A registered?
Mode-S code 4CAA6A is allocated to Ireland (IE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4CAA6A broadcasting right now?
No active broadcast right now. Last signal was Jun 11, 14:50 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4CAA6A, octal 23125152, decimal 5,024,362.
What flights does 4CAA6A operate?
Mode-S 4CAA6A has broadcast 1 distinct callsign, including RYR18ZU.