sensors Mode-S transponder

4CAEAF

ICAO 24-bit transponder address · allocated to Ireland

Currently assigned to EI-RZF · BOEING 737 MAX 8

Hex
4CAEAF
Octal
23127257
Decimal
5,025,455
Country
IE
Tail
EI-RZF
Type
B38M
Transponder active on ground
Flights observed
7
Distinct callsigns
3
Country
IE
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 4CAEAF.

Country allocation

The ICAO 24-bit address 4CAEAF 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
NOS1460 Neos 4 2026-04-13
NOS55FM - 2 2026-04-13
NOS24UA - 1 2026-04-12

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-13 NOS1460 FUE → MXP Apr 13, 16:50 UTCApr 13, 19:10 UTC2h 20m
2026-04-13 NOS1460 FUE → MXP Apr 13, 08:20 UTCApr 13, 10:25 UTC2h 5m
2026-04-13 NOS1460 FUE → MXP Apr 13, 07:55 UTCApr 13, 10:25 UTC2h 30m
2026-04-13 NOS1460 FUE → MXP Apr 13, 07:15 UTCApr 13, 08:15 UTC1h 0m
2026-04-13 NOS55FM - Apr 13, 00:20 UTCApr 13, 02:00 UTC1h 40m
2026-04-12 NOS55FM - Apr 12, 23:55 UTCApr 13, 02:00 UTC2h 5m
2026-04-12 NOS24UA - Apr 12, 17:15 UTCApr 12, 20:05 UTC2h 50m

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

Mode-S 4CAEAF frequently asked

What is Mode-S code 4CAEAF?
4CAEAF is an ICAO 24-bit transponder address. Allocated to Ireland. Assigned to EI-RZF.
Where is Mode-S 4CAEAF registered?
Mode-S code 4CAEAF is allocated to Ireland (IE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4CAEAF broadcasting right now?
Mode-S 4CAEAF is currently broadcasting from the ground.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4CAEAF, octal 23127257, decimal 5,025,455.
What flights does 4CAEAF operate?
Mode-S 4CAEAF has broadcast 3 distinct callsigns, including NOS1460, NOS55FM, NOS24UA.