sensors Mode-S transponder

4CAC65

ICAO 24-bit transponder address · allocated to Ireland

Currently assigned to EI-AZD · BOEING 737-800

Hex
4CAC65
Octal
23126145
Decimal
5,024,869
Country
IE
Tail
EI-AZD
Type
B738
No current signal · last broadcast 1d ago
Flights observed
5
Distinct callsigns
3
Country
IE
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 4CAC65.

Country allocation

The ICAO 24-bit address 4CAC65 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 3 distinct

Callsign Airline Flights Last seen
BCS95W - 2 2026-04-13
BCS32B - 2 2026-04-13
BCS21Q European Air Transport 1 2026-04-13

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-13 BCS21Q CDG → BOD Apr 13, 22:00 UTCApr 13, 22:35 UTC35m
2026-04-13 BCS32B - Apr 13, 19:50 UTCApr 13, 20:10 UTC20m
2026-04-13 BCS32B - Apr 13, 19:10 UTCApr 13, 20:10 UTC1h 0m
2026-04-13 BCS95W - Apr 13, 00:20 UTCApr 13, 01:55 UTC1h 35m
2026-04-13 BCS95W LEJ → BOD Apr 13, 00:00 UTCApr 13, 01:55 UTC1h 55m

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 EI-AZD page for operator, model, and routing details .

Mode-S 4CAC65 frequently asked

What is Mode-S code 4CAC65?
4CAC65 is an ICAO 24-bit transponder address. Allocated to Ireland. Assigned to EI-AZD.
Where is Mode-S 4CAC65 registered?
Mode-S code 4CAC65 is allocated to Ireland (IE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4CAC65 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 4CAC65, octal 23126145, decimal 5,024,869.
What flights does 4CAC65 operate?
Mode-S 4CAC65 has broadcast 3 distinct callsigns, including BCS95W, BCS32B, BCS21Q.