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sensors Mode-S transponder

4CA857

ICAO 24-bit transponder address · allocated to Ireland

Currently assigned to EI-EMO · BOEING 737-800

Hex
4CA857
Octal
23124127
Decimal
5,023,831
Country
IE
Tail
EI-EMO
Type
B738
Transponder active on ground
Flights observed
651
Distinct callsigns
20
Country
IE
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S 4CA857.

Country allocation

The ICAO 24-bit address 4CA857 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
RYR71LM Ryanair 6 2026-06-03
RYR1FF Ryanair 6 2026-06-03
RYR7209 Ryanair 5 2026-06-02
RYR6HR Ryanair 5 2026-06-02
RYR8UC Ryanair 4 2026-05-01
RYR8RB - 4 2026-06-16
RYR8HX Ryanair 4 2026-05-30
RYR615 Ryanair 4 2026-06-02
RYR611A Ryanair 4 2026-05-30
RYR5AD Ryanair 4 2026-06-15
RYR4PN - 4 2026-07-13
RYR3UR - 4 2026-07-13
RYR292Q - 4 2026-06-16
RYR28SP Ryanair 4 2026-06-15
RYR19KU Ryanair 4 2026-06-02
RYR13KA Ryanair 4 2026-05-01
RYR97BR Ryanair 3 2026-04-15
RYR91KF Ryanair 3 2026-05-16
RYR9141 Ryanair 3 2026-05-27
RYR79QE Ryanair 3 2026-04-18

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 RYR70QN - Jul 14, 13:15 UTCJul 14, 13:45 UTC30m
2026-07-14 RYR9RA - Jul 14, 11:20 UTCJul 14, 12:10 UTC50m
2026-07-14 RYR39ED - Jul 14, 09:30 UTCJul 14, 10:20 UTC50m
2026-07-14 RYR17PY - Jul 14, 07:25 UTCJul 14, 08:50 UTC1h 25m
2026-07-14 RYR89NK - Jul 14, 04:55 UTCJul 14, 06:10 UTC1h 15m
2026-07-13 RYR3UR - Jul 13, 20:20 UTCJul 13, 21:35 UTC1h 15m
2026-07-13 RYR4PN - Jul 13, 18:15 UTCJul 13, 19:20 UTC1h 5m
2026-07-13 RYR78ZG - Jul 13, 16:25 UTCJul 13, 17:35 UTC1h 10m
2026-07-13 RYR4WD - Jul 13, 14:00 UTCJul 13, 15:05 UTC1h 5m
2026-07-13 RYR907P - Jul 13, 12:05 UTCJul 13, 13:10 UTC1h 5m
2026-07-13 RYR5649 - Jul 13, 09:40 UTCJul 13, 10:25 UTC45m
2026-07-13 RYR48ZK - Jul 13, 06:50 UTCJul 13, 08:40 UTC1h 50m
2026-07-13 RYR33EL TRS → VLC Jul 13, 04:10 UTCJul 13, 06:05 UTC1h 55m
2026-07-12 RYR1ZW - Jul 12, 20:10 UTCJul 12, 21:30 UTC1h 20m
2026-07-12 RYR5427 - Jul 12, 17:50 UTCJul 12, 19:05 UTC1h 15m
2026-07-12 RYR60PR - Jul 12, 16:10 UTCJul 12, 17:10 UTC1h 0m
2026-07-12 RYR6HL - Jul 12, 14:25 UTCJul 12, 15:20 UTC55m
2026-07-12 RYR6HL TRS → TRS Jul 12, 14:10 UTCJul 12, 14:15 UTC5m
2026-07-12 RYR3UR - Jul 12, 12:05 UTCJul 12, 13:20 UTC1h 15m
2026-07-12 RYR4PN - Jul 12, 10:10 UTCJul 12, 11:15 UTC1h 5m
2026-07-12 RYR78ZG - Jul 12, 08:25 UTCJul 12, 09:30 UTC1h 5m
2026-07-12 RYR4WD - Jul 12, 05:55 UTCJul 12, 06:55 UTC1h 0m
2026-07-11 RYR2426 - Jul 11, 19:00 UTCJul 11, 21:40 UTC2h 40m
2026-07-11 RYR2427 TRS → SVQ Jul 11, 15:25 UTCJul 11, 18:05 UTC2h 40m
2026-07-11 RYR3UR - Jul 11, 13:30 UTCJul 11, 14:45 UTC1h 15m
2026-07-11 RYR4PN - Jul 11, 11:20 UTCJul 11, 12:20 UTC1h 0m
2026-07-11 RYR8742 ARN → TRS Jul 11, 08:10 UTCJul 11, 10:10 UTC2h 0m
2026-07-11 RYR8743 TRS → ARN Jul 11, 05:20 UTCJul 11, 07:30 UTC2h 10m
2026-07-10 RYR83SL OLB → TRS Jul 10, 21:05 UTCJul 10, 22:00 UTC55m
2026-07-10 RYR70QN TRS → OLB Jul 10, 19:15 UTCJul 10, 20:20 UTC1h 5m
2026-07-10 RYR78HC BCN → TRS Jul 10, 17:10 UTCJul 10, 18:35 UTC1h 25m
2026-07-10 RYR94VL TRS → BCN Jul 10, 14:05 UTCJul 10, 15:45 UTC1h 40m
2026-07-10 RYR96ZJ CAG → TRS Jul 10, 11:20 UTCJul 10, 12:35 UTC1h 15m
2026-07-10 RYR97YQ - Jul 10, 09:15 UTCJul 10, 10:20 UTC1h 5m
2026-07-10 RYR17PY - Jul 10, 06:45 UTCJul 10, 08:10 UTC1h 25m
2026-07-10 RYR89NK - Jul 10, 04:35 UTCJul 10, 05:55 UTC1h 20m
2026-07-09 RYR99ZG - Jul 9, 20:15 UTCJul 9, 21:50 UTC1h 35m
2026-07-09 RYR27JN - Jul 9, 17:35 UTCJul 9, 19:25 UTC1h 50m
2026-07-09 RYR3UR - Jul 9, 15:35 UTCJul 9, 16:50 UTC1h 15m
2026-07-09 RYR4PN - Jul 9, 13:25 UTCJul 9, 14:30 UTC1h 5m
2026-07-09 RYR9RA - Jul 9, 11:40 UTCJul 9, 12:35 UTC55m
2026-07-09 RYR39ED - Jul 9, 09:15 UTCJul 9, 10:25 UTC1h 10m
2026-07-09 RYR358T MLA → TRS Jul 9, 06:55 UTCJul 9, 08:40 UTC1h 45m
2026-07-09 RYR3695 TRS → MLA Jul 9, 04:30 UTCJul 9, 06:05 UTC1h 35m
2026-07-08 RYR83SL - Jul 8, 21:25 UTCJul 8, 22:25 UTC1h 0m
2026-07-08 RYR70QN TRS → OLB Jul 8, 19:20 UTCJul 8, 20:20 UTC1h 0m
2026-07-08 RYR99ZG - Jul 8, 16:30 UTCJul 8, 18:10 UTC1h 40m
2026-07-08 RYR7LU - Jul 8, 13:10 UTCJul 8, 15:20 UTC2h 10m
2026-07-08 RYR27LQ - Jul 8, 09:35 UTCJul 8, 11:40 UTC2h 5m
2026-07-08 RYR4GC - Jul 8, 07:50 UTCJul 8, 08:35 UTC45m

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

Mode-S 4CA857 frequently asked

What is Mode-S code 4CA857?
4CA857 is an ICAO 24-bit transponder address. Allocated to Ireland. Assigned to EI-EMO.
Where is Mode-S 4CA857 registered?
Mode-S code 4CA857 is allocated to Ireland (IE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4CA857 broadcasting right now?
Mode-S 4CA857 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 4CA857, octal 23124127, decimal 5,023,831.
What flights does 4CA857 operate?
Mode-S 4CA857 has broadcast 20 distinct callsigns, including RYR71LM, RYR1FF, RYR7209, RYR6HR, RYR8UC.