sensors Mode-S transponder

4CAC23

ICAO 24-bit transponder address · allocated to Ireland

Currently assigned to EI-HGL · BOEING 737 MAX 8

Hex
4CAC23
Octal
23126043
Decimal
5,024,803
Country
IE
Tail
EI-HGL
Type
B38M
Broadcasting now · callsign RYR6JA · 40,000 ft
Flights observed
302
Distinct callsigns
20
Country
IE
Last broadcast
40m ago

Current position

4CAC23 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 4CAC23 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
RYR9JT Ryanair 4 2026-05-15
RYR52SL Ryanair 4 2026-05-15
RYR7EE - 3 2026-04-15
RYR7668 Ryanair 3 2026-05-16
RYR50UT Ryanair 3 2026-05-06
RYR506G - 3 2026-04-13
RYR439L Ryanair 3 2026-05-24
RYR314U Ryanair 3 2026-05-16
RYR22LN - 3 2026-04-15
RYR20FV - 3 2026-04-13
RYR1YJ Ryanair 3 2026-05-06
RYR1UB Ryanair 3 2026-05-16
RYR9YF Ryanair 2 2026-05-02
RYR99RH Ryanair 2 2026-04-14
RYR98ST Ryanair 2 2026-05-13
RYR97DM Ryanair 2 2026-05-13
RYR96XP Ryanair 2 2026-04-30
RYR89HU Ryanair 2 2026-05-24
RYR88FE - 2 2026-04-14
RYR863C Ryanair 2 2026-04-16

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 RYR6JA MAD → TFS May 30, 07:15 UTCMay 30, 08:45 UTC1h 30m
2026-05-30 RYR5976 ARN → DBV May 30, 04:00 UTCMay 30, 06:25 UTC2h 25m
2026-05-29 RYR8FE OUD → MRS May 29, 18:00 UTCMay 29, 21:50 UTC3h 50m
2026-05-29 RYR5UB LGW → DUB May 29, 13:25 UTCMay 29, 15:40 UTC2h 15m
2026-05-29 RYR5YV GRO → DUB May 29, 10:10 UTCMay 29, 12:35 UTC2h 25m
2026-05-29 RYR3AD BRS → RIX May 29, 08:20 UTCMay 29, 09:15 UTC55m
2026-05-29 RYR27YZ ORK → PMI May 29, 06:40 UTCMay 29, 07:30 UTC50m
2026-05-28 RYR57BR GDN → AGP May 28, 19:20 UTCMay 28, 22:40 UTC3h 20m
2026-05-28 RYR52WA PMO → CGN May 28, 14:50 UTCMay 28, 18:20 UTC3h 30m
2026-05-28 RYR83LD CPH → AGP May 28, 09:55 UTCMay 28, 13:05 UTC3h 10m
2026-05-28 RYR26RY AGP → CPH May 28, 05:40 UTCMay 28, 08:50 UTC3h 10m
2026-05-27 RYR9JW LPL → ALC May 27, 16:30 UTCMay 27, 19:00 UTC2h 30m
2026-05-27 RYR4KR AGP → EIN May 27, 13:15 UTCMay 27, 15:40 UTC2h 25m
2026-05-27 RYR4GZ STN → PSR May 27, 09:10 UTCMay 27, 11:30 UTC2h 20m
2026-05-27 RYR21VJ AGP → TSF May 27, 05:55 UTCMay 27, 08:15 UTC2h 20m
2026-05-26 RYR4SZ KRK → CPH May 26, 21:14 UTCMay 26, 21:59 UTC45m
2026-05-26 RYR4RL AGP → LIS May 26, 19:20 UTCMay 26, 20:20 UTC1h 0m
2026-05-26 RYR5UB LGW → DUB May 26, 15:54 UTCMay 26, 18:14 UTC2h 20m
2026-05-26 RYR768F SVQ → CRL May 26, 12:35 UTCMay 26, 14:45 UTC2h 10m
2026-05-26 RYR126H VLC → BRS May 26, 09:15 UTCMay 26, 11:39 UTC2h 25m
2026-05-26 RYR8YU EDI → OTP May 26, 07:05 UTCMay 26, 08:24 UTC1h 20m
2026-05-26 RYR10VU CRL → MRS May 26, 04:50 UTCMay 26, 06:14 UTC1h 25m
2026-05-25 RYR3ZM RHO → CRL May 25, 15:25 UTCMay 25, 18:35 UTC3h 10m
2026-05-25 RYR69WR CRL → RHO May 25, 11:15 UTCMay 25, 14:35 UTC3h 20m
2026-05-25 RYR85HE EDI → CRL May 25, 08:25 UTCMay 25, 09:40 UTC1h 15m
2026-05-25 RYR1HF STN → BZG May 25, 06:15 UTCMay 25, 07:30 UTC1h 15m
2026-05-24 RYR84KK LEI → CRL May 24, 21:10 UTCMay 24, 23:30 UTC2h 20m
2026-05-24 RYR9898 CPH → VIE May 24, 20:00 UTCMay 24, 20:25 UTC25m
2026-05-24 RYR439L BRS → AGP May 24, 16:30 UTCMay 24, 18:40 UTC2h 10m
2026-05-24 RYR89HU AGP → BRS May 24, 13:10 UTCMay 24, 15:25 UTC2h 15m
2026-05-24 RYR1RM BUD → AGP May 24, 08:05 UTCMay 24, 11:05 UTC3h 0m
2026-05-24 RYR3BQ AGP → BUD May 24, 04:00 UTCMay 24, 07:15 UTC3h 15m
2026-05-23 RYR88WN LIS → AGP May 23, 20:55 UTCMay 23, 21:40 UTC45m
2026-05-23 RYR6626 AGP → LIS May 23, 18:55 UTCMay 23, 19:55 UTC1h 0m
2026-05-23 RYR77TG ALC → LTN May 23, 15:25 UTCMay 23, 17:50 UTC2h 25m
2026-05-23 RYR87CG AGP → SNN May 23, 12:05 UTCMay 23, 14:25 UTC2h 20m
2026-05-23 RYR1YL ZAD → BUD May 23, 07:30 UTCMay 23, 09:45 UTC2h 15m
2026-05-23 RYR117J AGP → BOH May 23, 04:10 UTCMay 23, 06:20 UTC2h 10m
2026-05-22 RYR4242 VIT → AGP May 22, 21:10 UTCMay 22, 22:15 UTC1h 5m
2026-05-22 RYR49XN AGP → VIT May 22, 19:15 UTCMay 22, 20:10 UTC55m
2026-05-22 RYR9RL FEZ → NTE May 22, 15:45 UTCMay 22, 18:05 UTC2h 20m
2026-05-22 RYR618X AGP → CWL May 22, 12:40 UTCMay 22, 14:55 UTC2h 15m
2026-05-22 RYR2YA DUB → PRG May 22, 08:20 UTCMay 22, 10:50 UTC2h 30m
2026-05-22 RYR4UU AGA → FEZ May 22, 04:20 UTCMay 22, 06:45 UTC2h 25m
2026-05-21 RYR86QT CTA → FCO May 21, 19:25 UTCMay 21, 22:10 UTC2h 45m
2026-05-21 RYR63GU - May 21, 16:01 UTCMay 21, 18:30 UTC2h 30m
2026-05-21 RYR439L BRS → AGP May 21, 12:15 UTCMay 21, 14:30 UTC2h 15m
2026-05-21 RYR3TU MRS → NAP May 21, 08:50 UTCMay 21, 11:25 UTC2h 35m
2026-05-21 RYR8681 BRS → KUN May 21, 05:45 UTCMay 21, 08:05 UTC2h 20m
2026-05-20 RYR70LT IBZ → BRS May 20, 22:50 UTCMay 21, 00:55 UTC2h 5m

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

Mode-S 4CAC23 frequently asked

What is Mode-S code 4CAC23?
4CAC23 is an ICAO 24-bit transponder address. Allocated to Ireland. Assigned to EI-HGL.
Where is Mode-S 4CAC23 registered?
Mode-S code 4CAC23 is allocated to Ireland (IE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4CAC23 broadcasting right now?
Yes. Mode-S 4CAC23 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4CAC23, octal 23126043, decimal 5,024,803.
What flights does 4CAC23 operate?
Mode-S 4CAC23 has broadcast 20 distinct callsigns, including RYR9JT, RYR52SL, RYR7EE, RYR7668, RYR50UT.