Apparatus

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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 RYR9XH · 30,475 ft
Flights observed
588
Distinct callsigns
20
Country
IE
Last broadcast
6m 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
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
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
RYR3053 Ryanair 3 2026-06-03
RYR2AA Ryanair 3 2026-05-05
RYR29DB Ryanair 3 2026-05-05

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 RYR9XH - Jul 14, 10:35 UTCJul 14, 11:15 UTC40m
2026-07-14 RYR83BZ - Jul 14, 08:00 UTCJul 14, 09:50 UTC1h 50m
2026-07-14 RYR6FC - Jul 14, 04:50 UTCJul 14, 07:10 UTC2h 20m
2026-07-13 RYR3DE - Jul 13, 21:30 UTCJul 13, 22:30 UTC1h 0m
2026-07-13 RYR28ZB - Jul 13, 19:30 UTCJul 13, 20:35 UTC1h 5m
2026-07-13 RYR79FR ALC → BRI Jul 13, 16:50 UTCJul 13, 18:45 UTC1h 55m
2026-07-13 RYR5HH MRS → SNN Jul 13, 13:25 UTCJul 13, 15:50 UTC2h 25m
2026-07-13 RYR10TB - Jul 13, 11:05 UTCJul 13, 12:10 UTC1h 5m
2026-07-13 RYR5WR - Jul 13, 09:00 UTCJul 13, 10:15 UTC1h 15m
2026-07-13 RYR98ZY - Jul 13, 06:35 UTCJul 13, 08:05 UTC1h 30m
2026-07-13 RYR88JA - Jul 13, 03:55 UTCJul 13, 05:40 UTC1h 45m
2026-07-12 RYR9536 - Jul 12, 20:30 UTCJul 12, 21:55 UTC1h 25m
2026-07-12 RYR5KA - Jul 12, 18:20 UTCJul 12, 19:35 UTC1h 15m
2026-07-12 RYR36VA - Jul 12, 15:55 UTCJul 12, 17:10 UTC1h 15m
2026-07-12 RYR5PB BRI → MXP Jul 12, 13:15 UTCJul 12, 14:40 UTC1h 25m
2026-07-12 RYR3DE - Jul 12, 11:20 UTCJul 12, 12:15 UTC55m
2026-07-12 RYR28ZB - Jul 12, 09:15 UTCJul 12, 10:15 UTC1h 0m
2026-07-12 RYR7ZD - Jul 12, 06:55 UTCJul 12, 08:01 UTC1h 5m
2026-07-12 RYR9874 BRI → MLA Jul 12, 04:35 UTCJul 12, 05:35 UTC1h 0m
2026-07-11 RYR241F - Jul 11, 22:10 UTCJul 11, 22:55 UTC45m
2026-07-11 RYR408P - Jul 11, 20:30 UTCJul 11, 21:15 UTC45m
2026-07-11 RYR95AT - Jul 11, 18:45 UTCJul 11, 19:40 UTC55m
2026-07-11 RYR5ZL - Jul 11, 16:45 UTCJul 11, 17:40 UTC55m
2026-07-11 RYR2PK NUE → BRI Jul 11, 12:00 UTCJul 11, 13:30 UTC1h 30m
2026-07-11 RYR10ZJ BRI → NUE Jul 11, 09:25 UTCJul 11, 11:05 UTC1h 40m
2026-07-11 RYR9693 - Jul 11, 07:20 UTCJul 11, 07:50 UTC30m
2026-07-11 RYR5RT - Jul 11, 05:45 UTCJul 11, 06:05 UTC20m
2026-07-10 RYR36VA - Jul 10, 21:25 UTCJul 10, 22:40 UTC1h 15m
2026-07-10 RYR5PB BRI → MXP Jul 10, 19:05 UTCJul 10, 20:25 UTC1h 20m
2026-07-10 RYR1EV - Jul 10, 17:15 UTCJul 10, 17:55 UTC40m
2026-07-10 RYR77DM - Jul 10, 15:25 UTCJul 10, 16:10 UTC45m
2026-07-10 RYR28SK - Jul 10, 12:55 UTCJul 10, 13:50 UTC55m
2026-07-10 RYR5JK - Jul 10, 10:10 UTCJul 10, 11:20 UTC1h 10m
2026-07-10 RYR68QQ - Jul 10, 08:10 UTCJul 10, 09:10 UTC1h 0m
2026-07-10 RYR81BC - Jul 10, 06:00 UTCJul 10, 07:10 UTC1h 10m
2026-07-10 RYR8BF - Jul 10, 03:50 UTCJul 10, 05:00 UTC1h 10m
2026-07-09 RYR8QZ IBZ → BLQ Jul 9, 21:15 UTCJul 9, 22:50 UTC1h 35m
2026-07-09 RYR520K - Jul 9, 18:55 UTCJul 9, 20:20 UTC1h 25m
2026-07-09 RYR6017 ATH → BLQ Jul 9, 16:10 UTCJul 9, 18:05 UTC1h 55m
2026-07-09 RYR42HR - Jul 9, 13:25 UTCJul 9, 15:15 UTC1h 50m
2026-07-09 RYR2FL - Jul 9, 11:00 UTCJul 9, 12:15 UTC1h 15m
2026-07-09 RYR47YB - Jul 9, 08:45 UTCJul 9, 09:50 UTC1h 5m
2026-07-09 RYR17UZ BCN → BLQ Jul 9, 06:40 UTCJul 9, 08:00 UTC1h 20m
2026-07-09 RYR36HD - Jul 9, 03:55 UTCJul 9, 05:05 UTC1h 10m
2026-07-08 RYR5G SVQ → BLQ Jul 8, 20:30 UTCJul 8, 22:40 UTC2h 10m
2026-07-08 RYR13VP - Jul 8, 17:10 UTCJul 8, 19:20 UTC2h 10m
2026-07-08 RYR89EQ - Jul 8, 15:00 UTCJul 8, 15:55 UTC55m
2026-07-08 RYR62QT - Jul 8, 13:15 UTCJul 8, 14:10 UTC55m
2026-07-08 RYR25FL - Jul 8, 07:45 UTCJul 8, 10:00 UTC2h 15m
2026-07-08 RYR63DQ - Jul 8, 04:25 UTCJul 8, 06:45 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-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.