sensors Mode-S transponder

4CAC2B

ICAO 24-bit transponder address · allocated to Ireland

Currently assigned to EI-FGU

Hex
4CAC2B
Octal
23126053
Decimal
5,024,811
Country
IE
Tail
EI-FGU
Type
SKRA
No current signal · last broadcast 4h ago
Flights observed
5
Distinct callsigns
1
Country
IE
Last broadcast
4h ago

Last known position

Most recent position reported by Mode-S 4CAC2B.

Country allocation

The ICAO 24-bit address 4CAC2B 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
EIFGU - 5 2026-06-29

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-06-29 EIFGU - Jun 29, 17:19 UTCJun 29, 17:45 UTC25m
2026-06-29 EIFGU - Jun 29, 16:29 UTCJun 29, 16:39 UTC10m
2026-06-29 EIFGU - Jun 29, 13:09 UTCJun 29, 13:54 UTC45m
2026-06-28 EIFGU - Jun 28, 13:40 UTCJun 28, 14:14 UTC35m
2026-06-27 EIFGU - Jun 27, 16:59 UTCJun 27, 18:45 UTC1h 45m

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

Mode-S 4CAC2B frequently asked

What is Mode-S code 4CAC2B?
4CAC2B is an ICAO 24-bit transponder address. Allocated to Ireland. Assigned to EI-FGU.
Where is Mode-S 4CAC2B registered?
Mode-S code 4CAC2B is allocated to Ireland (IE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4CAC2B broadcasting right now?
No active broadcast right now. Last signal was 4h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4CAC2B, octal 23126053, decimal 5,024,811.
What flights does 4CAC2B operate?
Mode-S 4CAC2B has broadcast 1 distinct callsign, including EIFGU.