sensors Mode-S transponder

4CAA54

ICAO 24-bit transponder address · allocated to Ireland

Currently assigned to EI-GPO · ATR-72-600

Hex
4CAA54
Octal
23125124
Decimal
5,024,340
Country
IE
Tail
EI-GPO
Type
AT76
No current signal · last broadcast 12h ago
Flights observed
18
Distinct callsigns
13
Country
IE
Last broadcast
12h ago

Last known position

Most recent position reported by Mode-S 4CAA54.

Country allocation

The ICAO 24-bit address 4CAA54 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 13 distinct

Callsign Airline Flights Last seen
EAI23C - 3 2026-04-13
EAI35C - 2 2026-04-13
EAI31F - 2 2026-04-14
EAI21HA - 2 2026-04-13
EAI3RG - 1 2026-04-13
EAI3HP Elite Air 1 2026-04-14
EAI33S - 1 2026-04-12
EAI31Q - 1 2026-04-12
EAI2GL - 1 2026-04-13
EAI25LG - 1 2026-04-13
EAI24CE - 1 2026-04-13
EAI22MW - 1 2026-04-13
EAI19L - 1 2026-04-14

Recent flights last 18

DateFlightRouteTakeoffLandingDuration
2026-04-14 EAI19L - Apr 14, 10:55 UTCApr 14, 11:05 UTC10m
2026-04-14 EAI31F - Apr 14, 09:10 UTCApr 14, 10:05 UTC55m
2026-04-14 EAI31F - Apr 14, 08:55 UTCApr 14, 09:05 UTC10m
2026-04-14 EAI3HP DUB → EDI Apr 14, 07:10 UTCApr 14, 07:55 UTC45m
2026-04-13 EAI3RG EDI → DUB Apr 13, 18:50 UTCApr 13, 19:45 UTC55m
2026-04-13 EAI35C DUB → EDI Apr 13, 17:05 UTCApr 13, 18:00 UTC55m
2026-04-13 EAI25LG GLA → DUB Apr 13, 15:00 UTCApr 13, 15:50 UTC50m
2026-04-13 EAI24CE - Apr 13, 13:20 UTCApr 13, 14:05 UTC45m
2026-04-13 EAI23C - Apr 13, 12:20 UTCApr 13, 12:40 UTC20m
2026-04-13 EAI23C - Apr 13, 11:55 UTCApr 13, 12:40 UTC45m
2026-04-13 EAI23C - Apr 13, 11:40 UTCApr 13, 12:15 UTC35m
2026-04-13 EAI22MW DUB → GLA Apr 13, 10:10 UTCApr 13, 10:55 UTC45m
2026-04-13 EAI21HA - Apr 13, 08:20 UTCApr 13, 08:50 UTC30m
2026-04-13 EAI21HA - Apr 13, 07:55 UTCApr 13, 08:15 UTC20m
2026-04-13 EAI2GL DUB → GLA Apr 13, 06:15 UTCApr 13, 07:00 UTC45m
2026-04-12 EAI35C - Apr 12, 19:55 UTCApr 12, 20:15 UTC20m
2026-04-12 EAI31Q - Apr 12, 18:20 UTCApr 12, 19:20 UTC1h 0m
2026-04-12 EAI33S - Apr 12, 17:15 UTCApr 12, 17:30 UTC15m

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

Mode-S 4CAA54 frequently asked

What is Mode-S code 4CAA54?
4CAA54 is an ICAO 24-bit transponder address. Allocated to Ireland. Assigned to EI-GPO.
Where is Mode-S 4CAA54 registered?
Mode-S code 4CAA54 is allocated to Ireland (IE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4CAA54 broadcasting right now?
No active broadcast right now. Last signal was 12h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4CAA54, octal 23125124, decimal 5,024,340.
What flights does 4CAA54 operate?
Mode-S 4CAA54 has broadcast 13 distinct callsigns, including EAI23C, EAI35C, EAI31F, EAI21HA, EAI3RG.