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
Transponder active on ground
Flights observed
612
Distinct callsigns
20
Country
IE
Last broadcast
Jul 26, 22:45 UTC

Last known position

Most recent position reported by Mode-S 4CAC23.

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
RYR9ET - 5 2026-07-16
RYR55HB - 5 2026-07-16
RYR9JT Ryanair 4 2026-05-15
RYR98ST Ryanair 4 2026-07-23
RYR6TX - 4 2026-07-17
RYR62HD Ryanair 4 2026-07-23
RYR52SL Ryanair 4 2026-05-15
RYR7EE - 3 2026-04-15
RYR7668 Ryanair 3 2026-05-16
RYR74WC - 3 2026-06-18
RYR63UE - 3 2026-07-18
RYR50UT Ryanair 3 2026-05-06
RYR506G - 3 2026-04-13
RYR439L Ryanair 3 2026-05-24
RYR35MN - 3 2026-07-17
RYR314U Ryanair 3 2026-05-16
RYR22LN - 3 2026-04-15
RYR20RR - 3 2026-07-18
RYR20FV - 3 2026-04-13
RYR1YJ Ryanair 3 2026-05-06

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 RYR990N LIS → EDI Jul 26, 21:10 UTCJul 26, 22:45 UTC1h 35m
2026-07-26 RYR668T BCN → BGY Jul 26, 16:35 UTCJul 26, 19:20 UTC2h 45m
2026-07-26 RYR8UL AGP → OPO Jul 26, 14:45 UTCJul 26, 15:35 UTC50m
2026-07-26 RYR86GY EDI → DUB Jul 26, 13:05 UTCJul 26, 13:50 UTC45m
2026-07-26 RYR3GQ STN → CDT Jul 26, 09:40 UTCJul 26, 12:05 UTC2h 25m
2026-07-26 RYR6TG NAP → BGY Jul 26, 06:30 UTCJul 26, 08:35 UTC2h 6m
2026-07-25 RYR8CX BLL → MAD Jul 25, 21:15 UTCJul 25, 23:40 UTC2h 25m
2026-07-25 RYR77SY VLC → NTE Jul 25, 16:50 UTCJul 25, 19:05 UTC2h 15m
2026-07-25 RYR8UL AGP → OPO Jul 25, 15:05 UTCJul 25, 15:45 UTC40m
2026-07-25 RYR86GY EDI → DUB Jul 25, 13:20 UTCJul 25, 14:00 UTC40m
2026-07-25 RYR73KY BCN → EDI Jul 25, 09:45 UTCJul 25, 12:10 UTC2h 25m
2026-07-25 RYR36PL EDI → BCN Jul 25, 05:40 UTCJul 25, 08:00 UTC2h 20m
2026-07-24 RYR74EM BER → EDI Jul 24, 21:05 UTCJul 24, 22:50 UTC1h 45m
2026-07-24 RYR3U - Jul 24, 15:20 UTCJul 24, 18:25 UTC3h 5m
2026-07-24 RYR31KN BER → HER Jul 24, 10:40 UTCJul 24, 13:10 UTC2h 30m
2026-07-24 RYR3WY TGD → BER Jul 24, 07:15 UTCJul 24, 09:00 UTC1h 45m
2026-07-24 RYR3PL PSA → WMI Jul 24, 04:45 UTCJul 24, 06:05 UTC1h 20m
2026-07-23 RYR12AV TRS → BER Jul 23, 19:25 UTCJul 23, 20:40 UTC1h 15m
2026-07-23 RYR7BW AMS → DUB Jul 23, 17:30 UTCJul 23, 18:35 UTC1h 5m
2026-07-23 RYR4359 - Jul 23, 14:00 UTCJul 23, 16:45 UTC2h 45m
2026-07-23 RYR2GL BER → KGS Jul 23, 10:20 UTCJul 23, 13:00 UTC2h 40m
2026-07-23 RYR62HD SKG → BER Jul 23, 07:05 UTCJul 23, 09:15 UTC2h 10m
2026-07-23 RYR98ST BER → SKG Jul 23, 04:10 UTCJul 23, 06:15 UTC2h 5m
2026-07-22 RYR8WT BGY → SDR Jul 22, 19:35 UTCJul 22, 20:55 UTC1h 20m
2026-07-22 RYR3NJ LTN → BZG Jul 22, 17:25 UTCJul 22, 18:35 UTC1h 10m
2026-07-22 RYR3LF - Jul 22, 14:50 UTCJul 22, 16:40 UTC1h 50m
2026-07-22 RYR44BG - Jul 22, 12:15 UTCJul 22, 13:55 UTC1h 40m
2026-07-22 RYR33BL BER → RHO Jul 22, 04:20 UTCJul 22, 11:30 UTC7h 10m
2026-07-21 RYR8YY - Jul 21, 19:25 UTCJul 21, 20:50 UTC1h 25m
2026-07-21 RYR77CN BER → STN Jul 21, 17:10 UTCJul 21, 18:35 UTC1h 25m
2026-07-21 RYR9PG - Jul 21, 15:00 UTCJul 21, 16:25 UTC1h 25m
2026-07-21 RYR5XX BER → PSA Jul 21, 12:25 UTCJul 21, 14:05 UTC1h 40m
2026-07-21 RYR3QE PMO → BGY Jul 21, 08:50 UTCJul 21, 11:20 UTC2h 30m
2026-07-21 RYR4JQ EDI → BUD Jul 21, 04:30 UTCJul 21, 07:20 UTC2h 50m
2026-07-20 RYR3U - Jul 20, 15:35 UTCJul 20, 18:15 UTC2h 40m
2026-07-20 RYR31KN - Jul 20, 11:15 UTCJul 20, 13:50 UTC2h 35m
2026-07-20 RYR50PQ - Jul 20, 08:15 UTCJul 20, 09:55 UTC1h 40m
2026-07-20 RYR50PQ - Jul 20, 07:45 UTCJul 20, 08:10 UTC25m
2026-07-20 RYR63VQ CRL → MRS Jul 20, 04:00 UTCJul 20, 06:10 UTC2h 10m
2026-07-19 RYR1VD BUD → BER Jul 19, 19:50 UTCJul 19, 20:55 UTC1h 5m
2026-07-19 RYR37YC BER → BUD Jul 19, 17:40 UTCJul 19, 18:45 UTC1h 5m
2026-07-19 RYR62HD SKG → BER Jul 19, 14:15 UTCJul 19, 16:20 UTC2h 5m
2026-07-19 RYR98ST - Jul 19, 11:15 UTCJul 19, 13:20 UTC2h 5m
2026-07-19 RYR61NG BCN → BER Jul 19, 08:10 UTCJul 19, 10:10 UTC2h 0m
2026-07-19 RYR2YR BER → BCN Jul 19, 04:25 UTCJul 19, 06:55 UTC2h 30m
2026-07-18 RYR8YY - Jul 18, 19:35 UTCJul 18, 20:50 UTC1h 15m
2026-07-18 RYR63UE - Jul 18, 15:55 UTCJul 18, 18:40 UTC2h 45m
2026-07-18 RYR20RR - Jul 18, 12:40 UTCJul 18, 15:05 UTC2h 25m
2026-07-18 RYR35SH - Jul 18, 08:45 UTCJul 18, 11:10 UTC2h 25m
2026-07-18 RYR9PJ - Jul 18, 05:20 UTCJul 18, 07:40 UTC2h 20m

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?
Mode-S 4CAC23 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 4CAC23, octal 23126043, decimal 5,024,803.
What flights does 4CAC23 operate?
Mode-S 4CAC23 has broadcast 20 distinct callsigns, including RYR9ET, RYR55HB, RYR9JT, RYR98ST, RYR6TX.