sensors Mode-S transponder

4CA855

ICAO 24-bit transponder address · allocated to Ireland

Currently assigned to EI-EMM · BOEING 737-800

Hex
4CA855
Octal
23124125
Decimal
5,023,829
Country
IE
Tail
EI-EMM
Type
B738
Broadcasting now · callsign RYR2975 · 17,600 ft
Flights observed
300
Distinct callsigns
20
Country
IE
Last broadcast
2h ago

Current position

4CA855 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 4CA855 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
RYR886U Ryanair 3 2026-05-25
RYR743Z Ryanair 3 2026-04-27
RYR6B Ryanair 3 2026-05-25
RYR2AA Ryanair 3 2026-05-05
RYR29DB Ryanair 3 2026-05-05
RYR20SE - 3 2026-04-13
RYR9MV - 2 2026-04-13
RYR9CL Ryanair 2 2026-04-16
RYR98RD - 2 2026-04-15
RYR945 Ryanair 2 2026-04-18
RYR93BN Ryanair 2 2026-05-27
RYR91CV - 2 2026-04-15
RYR908 Ryanair 2 2026-05-27
RYR8GM Ryanair 2 2026-04-17
RYR8586 Ryanair 2 2026-05-25
RYR82FL - 2 2026-05-21
RYR80KA Ryanair 2 2026-05-23
RYR7LY Ryanair 2 2026-04-27
RYR7JZ Ryanair 2 2026-04-16
RYR7H Ryanair 2 2026-05-21

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 RYR2976 ORK → CRL May 30, 05:30 UTCMay 30, 06:50 UTC1h 20m
2026-05-29 RYR62HT WRO → CIA May 29, 20:20 UTCMay 29, 21:10 UTC50m
2026-05-29 RYR9CA MAN → MLA May 29, 18:55 UTCMay 29, 19:40 UTC45m
2026-05-29 RYR77KA BRS → GRO May 29, 15:45 UTCMay 29, 18:00 UTC2h 15m
2026-05-29 RYR78EA EIN → PMI May 29, 12:20 UTCMay 29, 14:25 UTC2h 5m
2026-05-29 RYR737X AGP → ORK May 29, 08:20 UTCMay 29, 10:45 UTC2h 25m
2026-05-29 RYR74XJ ORK → AGP May 29, 04:40 UTCMay 29, 06:55 UTC2h 15m
2026-05-28 RYR533D STN → CLJ May 28, 20:20 UTCMay 28, 21:20 UTC1h 0m
2026-05-28 RYR97ZH ORK → LGW May 28, 18:20 UTCMay 28, 19:20 UTC1h 0m
2026-05-28 RYR89DJ REU → ORK May 28, 15:20 UTCMay 28, 17:25 UTC2h 5m
2026-05-28 RYR7VV PSR → TPS May 28, 11:55 UTCMay 28, 13:45 UTC1h 50m
2026-05-28 RYR8DY TLS → LIS May 28, 08:00 UTCMay 28, 10:10 UTC2h 10m
2026-05-28 RYR54LC ORK → FAO May 28, 04:50 UTCMay 28, 07:05 UTC2h 15m
2026-05-27 RYR3H KRK → BCN May 27, 22:15 UTCMay 27, 23:05 UTC50m
2026-05-27 RYR26UL BRI → TRN May 27, 20:25 UTCMay 27, 21:25 UTC1h 0m
2026-05-27 RYR334K STN → ORK May 27, 18:35 UTCMay 27, 19:30 UTC55m
2026-05-27 RYR908 ORK → STN May 27, 16:40 UTCMay 27, 17:45 UTC1h 5m
2026-05-27 RYR93BN GRO → ORK May 27, 14:00 UTCMay 27, 15:40 UTC1h 40m
2026-05-27 RYR93BN GRO → ORK May 27, 13:45 UTCMay 27, 13:55 UTC10m
2026-05-27 RYR919G CRL → TSF May 27, 10:55 UTCMay 27, 12:50 UTC1h 55m
2026-05-27 RYR3053 EDI → BVA May 27, 08:35 UTCMay 27, 09:45 UTC1h 10m
2026-05-27 RYR3054 BVA → EDI May 27, 06:25 UTCMay 27, 07:35 UTC1h 10m
2026-05-26 RYR334K STN → ORK May 26, 19:55 UTCMay 26, 20:54 UTC1h 0m
2026-05-26 RYR908 ORK → STN May 26, 17:44 UTCMay 26, 18:50 UTC1h 5m
2026-05-26 RYR9GG AHO → ORK May 26, 14:00 UTCMay 26, 16:24 UTC2h 25m
2026-05-26 RYR38WV ORK → AHO May 26, 10:29 UTCMay 26, 13:04 UTC2h 35m
2026-05-26 RYR2975 CRL → ORK May 26, 04:54 UTCMay 26, 06:14 UTC1h 20m
2026-05-25 RYR53TJ AGP → TFS May 25, 19:30 UTCMay 25, 20:45 UTC1h 15m
2026-05-25 RYR8586 CRL → TLS May 25, 17:30 UTCMay 25, 18:40 UTC1h 10m
2026-05-25 RYR33QC ALC → BRS May 25, 15:10 UTCMay 25, 16:35 UTC1h 25m
2026-05-25 RYR5WZ FMM → STN May 25, 12:00 UTCMay 25, 13:25 UTC1h 25m
2026-05-25 RYR6B STN → BUD May 25, 09:05 UTCMay 25, 11:20 UTC2h 15m
2026-05-25 RYR886U CRL → CTA May 25, 05:30 UTCMay 25, 07:45 UTC2h 15m
2026-05-24 RYR37FE GOA → CRL May 24, 19:05 UTCMay 24, 20:15 UTC1h 10m
2026-05-24 RYR4964 CRL → GOA May 24, 16:55 UTCMay 24, 18:10 UTC1h 15m
2026-05-24 RYR3689 QSR → CRL May 24, 13:55 UTCMay 24, 15:55 UTC2h 0m
2026-05-24 RYR3688 CRL → QSR May 24, 11:05 UTCMay 24, 12:50 UTC1h 45m
2026-05-24 RYR35NN ALC → CRL May 24, 08:05 UTCMay 24, 10:05 UTC2h 0m
2026-05-24 RYR12WW LIS → STN May 24, 04:50 UTCMay 24, 06:40 UTC1h 50m
2026-05-23 RYR1VK ZAD → BRE May 23, 19:05 UTCMay 23, 20:55 UTC1h 50m
2026-05-23 RYR5463 CRL → MAD May 23, 16:00 UTCMay 23, 17:45 UTC1h 45m
2026-05-23 RYR4796 CDT → CRL May 23, 12:55 UTCMay 23, 14:45 UTC1h 50m
2026-05-23 RYR10KU CRL → CDT May 23, 10:05 UTCMay 23, 11:45 UTC1h 40m
2026-05-23 RYR80KA PSR → CRL May 23, 07:15 UTCMay 23, 08:55 UTC1h 40m
2026-05-23 RYR10UK CRL → PSR May 23, 04:45 UTCMay 23, 06:20 UTC1h 35m
2026-05-22 RYR62RA STN → ORK May 22, 16:45 UTCMay 22, 18:55 UTC2h 10m
2026-05-22 RYR1EA BVA → DUB May 22, 13:45 UTCMay 22, 15:50 UTC2h 5m
2026-05-22 RYR6B STN → BUD May 22, 09:30 UTCMay 22, 11:50 UTC2h 20m
2026-05-22 RYR886U CRL → CTA May 22, 06:00 UTCMay 22, 08:10 UTC2h 10m
2026-05-21 RYR7H GOT → GDN May 21, 19:00 UTCMay 21, 20:05 UTC1h 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-EMM page for operator, model, and routing details .

Mode-S 4CA855 frequently asked

What is Mode-S code 4CA855?
4CA855 is an ICAO 24-bit transponder address. Allocated to Ireland. Assigned to EI-EMM.
Where is Mode-S 4CA855 registered?
Mode-S code 4CA855 is allocated to Ireland (IE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4CA855 broadcasting right now?
Yes. Mode-S 4CA855 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4CA855, octal 23124125, decimal 5,023,829.
What flights does 4CA855 operate?
Mode-S 4CA855 has broadcast 20 distinct callsigns, including RYR886U, RYR743Z, RYR6B, RYR2AA, RYR29DB.