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 RYR724W · 19,375 ft
Flights observed
670
Distinct callsigns
20
Country
IE
Last broadcast
Jul 26, 20:30 UTC

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
RYR908 Ryanair 6 2026-06-07
RYR95AT - 5 2026-07-11
RYR5ZL - 5 2026-07-11
RYR334K Ryanair 5 2026-06-03
RYR62PM Ryanair 4 2026-06-12
RYR97ZH Ryanair 3 2026-06-04
RYR93BN Ryanair 3 2026-06-03
RYR886U Ryanair 3 2026-05-25
RYR812 Ryanair 3 2026-07-26
RYR7QQ - 3 2026-07-21
RYR75LD - 3 2026-07-21
RYR743Z Ryanair 3 2026-04-27
RYR6B Ryanair 3 2026-05-25
RYR5TN Ryanair 3 2026-06-12
RYR5PB Ryanair 3 2026-07-12
RYR533D Ryanair 3 2026-06-04
RYR3H Ryanair 3 2026-06-06
RYR3DE - 3 2026-07-13
RYR36VA - 3 2026-07-12
RYR3054 Ryanair 3 2026-06-03

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 RYR812 DUB → EDI Jul 26, 19:50 UTCJul 26, 20:25 UTC35m
2026-07-26 RYR812 DUB → EDI Jul 26, 19:10 UTCJul 26, 19:35 UTC25m
2026-07-26 RYR7RB HHN → NDR Jul 26, 17:15 UTCJul 26, 19:00 UTC1h 45m
2026-07-26 RYR26VC DUB → HAM Jul 26, 14:45 UTCJul 26, 16:10 UTC1h 25m
2026-07-26 RYR2AJ BVA → FNC Jul 26, 13:05 UTCJul 26, 13:40 UTC35m
2026-07-26 RYR554 DUB → MAN Jul 26, 11:45 UTCJul 26, 12:20 UTC35m
2026-07-26 RYR47HU CGN → ACE Jul 26, 09:10 UTCJul 26, 10:40 UTC1h 30m
2026-07-26 RYR19WY DUB → AMS Jul 26, 06:10 UTCJul 26, 07:15 UTC1h 6m
2026-07-25 RYR669 BHX → DUB Jul 25, 20:55 UTCJul 25, 21:40 UTC45m
2026-07-25 RYR68BJ DUB → BHX Jul 25, 19:35 UTCJul 25, 20:15 UTC40m
2026-07-25 RYR96GG AGP → DUB Jul 25, 16:10 UTCJul 25, 18:50 UTC2h 40m
2026-07-25 RYR1TQ AGA → MAD Jul 25, 12:15 UTCJul 25, 14:55 UTC2h 40m
2026-07-25 RYR23BF EDI → DUB Jul 25, 10:05 UTCJul 25, 11:00 UTC55m
2026-07-25 RYR812 DUB → EDI Jul 25, 08:30 UTCJul 25, 09:20 UTC50m
2026-07-25 RYR1C CIY → PSA Jul 25, 06:35 UTCJul 25, 07:15 UTC40m
2026-07-25 RYR82ZE DUB → CWL Jul 25, 05:15 UTCJul 25, 05:50 UTC35m
2026-07-25 RYR82ZE DUB → CWL Jul 25, 05:05 UTCJul 25, 05:10 UTC5m
2026-07-24 RYR5TG CRL → ARN Jul 24, 21:30 UTCJul 24, 23:55 UTC2h 25m
2026-07-24 RYR7132 DUB → FAO Jul 24, 18:20 UTCJul 24, 20:40 UTC2h 20m
2026-07-24 RYR14RE - Jul 24, 16:35 UTCJul 24, 17:25 UTC50m
2026-07-24 RYR9HC - Jul 24, 14:25 UTCJul 24, 15:25 UTC1h 0m
2026-07-24 RYR76JC - Jul 24, 12:40 UTCJul 24, 13:35 UTC55m
2026-07-24 RYR39KL ZAD → STN Jul 24, 09:30 UTCJul 24, 11:35 UTC2h 5m
2026-07-24 RYR2VV BHX → ARN Jul 24, 06:45 UTCJul 24, 08:20 UTC1h 35m
2026-07-23 RYR9P LPA → HHN Jul 23, 19:35 UTCJul 23, 22:00 UTC2h 25m
2026-07-23 RYR2UX STN → SOF Jul 23, 16:30 UTCJul 23, 18:25 UTC1h 55m
2026-07-23 RYR6TX VRN → STN Jul 23, 13:50 UTCJul 23, 15:30 UTC1h 40m
2026-07-23 RYR35MN CLJ → BVA Jul 23, 11:20 UTCJul 23, 12:50 UTC1h 30m
2026-07-23 RYR7CQ BUD → CTA Jul 23, 08:55 UTCJul 23, 10:20 UTC1h 25m
2026-07-23 RYR11GQ STN → PRG Jul 23, 06:35 UTCJul 23, 08:05 UTC1h 30m
2026-07-22 RYR9CB TFS → MAN Jul 22, 19:30 UTCJul 22, 23:05 UTC3h 35m
2026-07-22 RYR63PD STN → ATH Jul 22, 15:10 UTCJul 22, 18:10 UTC3h 0m
2026-07-22 RYR65YK VLC → STN Jul 22, 04:15 UTCJul 22, 13:00 UTC8h 45m
2026-07-21 RYR7QQ MXP → VLC Jul 21, 17:15 UTCJul 21, 19:00 UTC1h 45m
2026-07-21 RYR75LD VLC → MXP Jul 21, 14:55 UTCJul 21, 16:20 UTC1h 25m
2026-07-21 RYR86TM BRS → VLC Jul 21, 12:10 UTCJul 21, 14:00 UTC1h 50m
2026-07-21 RYR849N VLC → BRS Jul 21, 09:15 UTCJul 21, 11:20 UTC2h 5m
2026-07-21 RYR3UF BNX → BER Jul 21, 06:15 UTCJul 21, 07:35 UTC1h 20m
2026-07-21 RYR9141 BHX → SNN Jul 21, 04:00 UTCJul 21, 05:20 UTC1h 20m
2026-07-20 RYR52RY - Jul 20, 19:45 UTCJul 20, 21:45 UTC2h 0m
2026-07-20 RYR65YK - Jul 20, 16:25 UTCJul 20, 18:30 UTC2h 5m
2026-07-20 RYR1699 IBZ → VLC Jul 20, 15:00 UTCJul 20, 15:25 UTC25m
2026-07-20 RYR418Z - Jul 20, 13:25 UTCJul 20, 13:55 UTC30m
2026-07-20 RYR50AM STN → VLC Jul 20, 09:55 UTCJul 20, 12:00 UTC2h 5m
2026-07-20 RYR6BN PMI → CGN Jul 20, 06:50 UTCJul 20, 09:00 UTC2h 10m
2026-07-20 RYR19KU IBZ → VLC Jul 20, 05:20 UTCJul 20, 05:45 UTC25m
2026-07-20 RYR615 VLC → IBZ Jul 20, 04:10 UTCJul 20, 04:35 UTC25m
2026-07-19 RYR19KL - Jul 19, 18:10 UTCJul 19, 20:30 UTC2h 20m
2026-07-19 RYR7202 - Jul 19, 14:15 UTCJul 19, 15:45 UTC1h 30m
2026-07-19 RYR19KU IBZ → VLC Jul 19, 12:40 UTCJul 19, 13:10 UTC30m

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 RYR908, RYR95AT, RYR5ZL, RYR334K, RYR62PM.