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sensors Mode-S transponder

4CAD51

ICAO 24-bit transponder address · allocated to Ireland

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

Hex
4CAD51
Octal
23126521
Decimal
5,025,105
Country
IE
Tail
EI-HDK
Type
AT76
No current signal · last broadcast Jul 26, 19:50 UTC
Flights observed
813
Distinct callsigns
20
Country
IE
Last broadcast
Jul 26, 19:50 UTC

Last known position

Most recent position reported by Mode-S 4CAD51.

Country allocation

The ICAO 24-bit address 4CAD51 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 20 distinct

Callsign Airline Flights Last seen
EAI73N - 17 2026-07-20
EAI09U - 17 2026-07-12
EAI8C Elite Air 16 2026-07-12
EAI69M Elite Air 15 2026-07-26
EAI53BS Elite Air 15 2026-07-23
EAI51C Elite Air 15 2026-07-18
EAI3RG Elite Air 15 2026-07-26
EAI38D Elite Air 15 2026-07-26
EAI93D Elite Air 14 2026-07-09
EAI50E - 14 2026-07-18
EAI42A Elite Air 14 2026-07-24
EAI37E - 14 2026-07-20
EAI95C Elite Air 13 2026-07-17
EAI8BR Elite Air 13 2026-07-25
EAI81A Elite Air 13 2026-07-25
EAI35C Elite Air 13 2026-07-26
EAI34N Elite Air 13 2026-07-24
EAI33S Elite Air 13 2026-07-06
EAI31Q Elite Air 13 2026-07-06
EAI25LG Elite Air 13 2026-07-26

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 EAI3RG EDI → DUB Jul 26, 18:50 UTCJul 26, 19:45 UTC55m
2026-07-26 EAI35C DUB → EDI Jul 26, 17:05 UTCJul 26, 18:00 UTC55m
2026-07-26 EAI25LG GLA → DUB Jul 26, 15:25 UTCJul 26, 16:15 UTC50m
2026-07-26 EAI24CE DUB → GLA Jul 26, 13:25 UTCJul 26, 14:25 UTC1h 0m
2026-07-26 EAI38D MAN → DUB Jul 26, 11:45 UTCJul 26, 12:35 UTC50m
2026-07-26 EAI69M DUB → MAN Jul 26, 09:55 UTCJul 26, 10:45 UTC50m
2026-07-26 EAI91M LBA → LBA Jul 26, 07:55 UTCJul 26, 09:05 UTC1h 10m
2026-07-26 EAI9L DUB → LBA Jul 26, 06:30 UTCJul 26, 07:15 UTC46m
2026-07-25 EAI79BX - Jul 25, 18:40 UTCJul 25, 19:40 UTC1h 0m
2026-07-25 EAI78BX - Jul 25, 16:55 UTCJul 25, 17:40 UTC45m
2026-07-25 EAI83Z BRS → DUB Jul 25, 15:20 UTCJul 25, 16:15 UTC55m
2026-07-25 EAI32B DUB → BRS Jul 25, 13:30 UTCJul 25, 14:35 UTC1h 5m
2026-07-25 EAI32B DUB → BRS Jul 25, 13:20 UTCJul 25, 13:25 UTC5m
2026-07-25 EAI81A BRS → DUB Jul 25, 11:30 UTCJul 25, 12:30 UTC1h 0m
2026-07-25 EAI4RA ORK → BRS Jul 25, 09:30 UTCJul 25, 10:30 UTC1h 0m
2026-07-25 EAI84LP BRS → BRS Jul 25, 07:40 UTCJul 25, 08:45 UTC1h 5m
2026-07-25 EAI8BR DUB → BRS Jul 25, 06:05 UTCJul 25, 07:05 UTC1h 0m
2026-07-24 EAI11M MAN → DUB Jul 24, 20:05 UTCJul 24, 20:50 UTC45m
2026-07-24 EAI3BM DUB → MAN Jul 24, 18:25 UTCJul 24, 19:15 UTC50m
2026-07-24 EAI71G NQY → DUB Jul 24, 16:45 UTCJul 24, 17:45 UTC1h 0m
2026-07-24 EAI62N DUB → NQY Jul 24, 15:15 UTCJul 24, 16:15 UTC1h 0m
2026-07-24 EAI55YA - Jul 24, 13:20 UTCJul 24, 14:20 UTC1h 0m
2026-07-24 EAI4WD DUB → EDI Jul 24, 11:25 UTCJul 24, 12:30 UTC1h 5m
2026-07-24 EAI34N ABZ → DUB Jul 24, 09:05 UTCJul 24, 10:30 UTC1h 25m
2026-07-24 EAI42A DUB → ABZ Jul 24, 06:55 UTCJul 24, 08:05 UTC1h 10m
2026-07-23 EAI3RG EDI → DUB Jul 23, 19:50 UTCJul 23, 20:40 UTC50m
2026-07-23 EAI35C DUB → EDI Jul 23, 17:45 UTCJul 23, 18:45 UTC1h 0m
2026-07-23 EAI89W NCL → DUB Jul 23, 16:00 UTCJul 23, 17:00 UTC1h 0m
2026-07-23 EAI79D DUB → NCL Jul 23, 14:10 UTCJul 23, 15:00 UTC50m
2026-07-23 EAI53BS EDI → DUB Jul 23, 11:35 UTCJul 23, 12:30 UTC55m
2026-07-23 EAI52NE DUB → EDI Jul 23, 09:30 UTCJul 23, 10:30 UTC1h 0m
2026-07-23 EAI21HA - Jul 23, 07:50 UTCJul 23, 08:40 UTC50m
2026-07-23 EAI2GL DUB → GLA Jul 23, 06:15 UTCJul 23, 07:05 UTC50m
2026-07-22 EAI89DF BRS → DUB Jul 22, 19:30 UTCJul 22, 20:25 UTC55m
2026-07-22 EAI17C ORK → BRS Jul 22, 17:40 UTCJul 22, 18:50 UTC1h 10m
2026-07-22 EAI18K BRS → ORK Jul 22, 15:55 UTCJul 22, 17:00 UTC1h 5m
2026-07-22 EAI86W DUB → BRS Jul 22, 13:50 UTCJul 22, 14:50 UTC1h 0m
2026-07-22 EAI53BS EDI → DUB Jul 22, 11:40 UTCJul 22, 12:40 UTC1h 0m
2026-07-21 EAI3RG EDI → DUB Jul 21, 18:40 UTCJul 21, 19:35 UTC55m
2026-07-21 EAI35C DUB → EDI Jul 21, 17:00 UTCJul 21, 18:00 UTC1h 0m
2026-07-21 EAI57K EDI → DUB Jul 21, 15:05 UTCJul 21, 16:00 UTC55m
2026-07-21 EAI6RC DUB → GLA Jul 21, 13:10 UTCJul 21, 14:10 UTC1h 0m
2026-07-21 EAI23C - Jul 21, 11:10 UTCJul 21, 11:55 UTC45m
2026-07-21 EAI22MW DUB → GLA Jul 21, 09:35 UTCJul 21, 10:25 UTC50m
2026-07-21 EAI81A BRS → DUB Jul 21, 07:35 UTCJul 21, 08:30 UTC55m
2026-07-21 EAI8BR DUB → BRS Jul 21, 05:55 UTCJul 21, 06:45 UTC50m
2026-07-20 EAI89DF BRS → DUB Jul 20, 19:40 UTCJul 20, 20:40 UTC1h 0m
2026-07-20 EAI17C ORK → BRS Jul 20, 17:40 UTCJul 20, 18:50 UTC1h 10m
2026-07-20 EAI18K BRS → ORK Jul 20, 15:50 UTCJul 20, 16:50 UTC1h 0m
2026-07-20 EAI86W DUB → BRS Jul 20, 14:05 UTCJul 20, 15:05 UTC1h 0m

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

Mode-S 4CAD51 frequently asked

What is Mode-S code 4CAD51?
4CAD51 is an ICAO 24-bit transponder address. Allocated to Ireland. Assigned to EI-HDK.
Where is Mode-S 4CAD51 registered?
Mode-S code 4CAD51 is allocated to Ireland (IE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4CAD51 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 19:50 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4CAD51, octal 23126521, decimal 5,025,105.
What flights does 4CAD51 operate?
Mode-S 4CAD51 has broadcast 20 distinct callsigns, including EAI73N, EAI09U, EAI8C, EAI69M, EAI53BS.