sensors Mode-S transponder

4CA961

ICAO 24-bit transponder address · allocated to Ireland

Currently assigned to EI-RZC · BOEING 737 MAX 8

Hex
4CA961
Octal
23124541
Decimal
5,024,097
Country
IE
Tail
EI-RZC
Type
B38M
No current signal · last broadcast 1h ago
Flights observed
58
Distinct callsigns
20
Country
IE
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S 4CA961.

Country allocation

The ICAO 24-bit address 4CA961 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
NOS1350 Neos 11 2026-05-11
NOS4357 Neos 7 2026-04-30
NOS5964 Neos 3 2026-05-29
NOS1446 Neos 3 2026-05-25
NOS6919 Neos 2 2026-05-23
NOS35EW - 2 2026-05-16
NOS2542 Neos 2 2026-05-26
NOS98AQ Neos 1 2026-05-08
NOS9806 Neos 1 2026-05-01
NOS9805 Neos 1 2026-05-01
NOS9802 - 1 2026-05-05
NOS9801 - 1 2026-05-05
NOS9457 - 1 2026-05-22
NOS8964 - 1 2026-05-29
NOS8807 - 1 2026-05-01
NOS8805 - 1 2026-05-01
NOS8802 - 1 2026-05-05
NOS8801 - 1 2026-05-05
NOS8458 - 1 2026-05-22
NOS8457 - 1 2026-05-22

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 NOS5973 SSH → MXP May 29, 15:55 UTCMay 30, 00:15 UTC8h 20m
2026-05-29 NOS5964 MXP → KGS May 29, 12:05 UTCMay 29, 14:45 UTC2h 40m
2026-05-29 NOS5964 MXP → KGS May 29, 10:50 UTCMay 29, 11:00 UTC10m
2026-05-29 NOS5964 MXP → KGS May 29, 07:15 UTCMay 29, 09:25 UTC2h 10m
2026-05-29 NOS8964 - May 29, 05:05 UTCMay 29, 05:45 UTC40m
2026-05-26 NOS2542 BLQ → RMF May 26, 06:14 UTCMay 26, 16:30 UTC10h 15m
2026-05-25 NOS1446 BLQ → FUE May 25, 20:09 UTCMay 25, 23:54 UTC3h 45m
2026-05-25 NOS1446 BLQ → FUE May 25, 13:25 UTCMay 25, 15:50 UTC2h 25m
2026-05-24 NOS23UR BLQ → RMF May 24, 14:45 UTCMay 24, 23:35 UTC8h 50m
2026-05-23 NOS33GL - May 23, 16:50 UTCMay 24, 01:40 UTC8h 51m
2026-05-23 NOS6919 SSH → BLQ May 23, 05:05 UTCMay 23, 14:00 UTC8h 55m
2026-05-22 NOS8458 ATH → BLQ May 22, 13:55 UTCMay 22, 15:50 UTC1h 55m
2026-05-22 NOS9457 - May 22, 09:00 UTCMay 22, 12:15 UTC3h 15m
2026-05-22 NOS8457 - May 22, 04:50 UTCMay 22, 06:40 UTC1h 50m
2026-05-19 NOS2542 BLQ → RMF May 19, 06:15 UTCMay 19, 16:50 UTC10h 35m
2026-05-18 NOS1446 BLQ → FUE May 18, 13:00 UTCMay 18, 23:40 UTC10h 39m
2026-05-17 NOS7619 RMF → BLQ May 17, 14:55 UTCMay 17, 23:50 UTC8h 55m
2026-05-16 NOS6589 RMF → BLQ May 16, 17:05 UTCMay 17, 01:55 UTC8h 50m
2026-05-16 NOS6919 SSH → BLQ May 16, 11:55 UTCMay 16, 15:50 UTC3h 55m
2026-05-16 NOS35EW - May 16, 06:45 UTCMay 16, 09:35 UTC2h 50m
2026-05-14 NOS4508 VRN → RMF May 14, 11:10 UTCMay 14, 22:05 UTC10h 55m
2026-05-11 NOS1350 LPA → MXP May 11, 06:15 UTCMay 11, 16:45 UTC10h 30m
2026-05-10 NOS7929 SSH → VRN May 10, 17:40 UTCMay 11, 01:50 UTC8h 10m
2026-05-10 NOS7629 SSH → BLQ May 10, 15:29 UTCMay 10, 16:04 UTC35m
2026-05-10 NOS80AM VRN → SSH May 10, 05:34 UTCMay 10, 14:20 UTC8h 45m
2026-05-09 NOS18JZ SSH → VRN May 9, 07:15 UTCMay 9, 15:55 UTC8h 40m
2026-05-08 NOS403 CUN → MXP May 8, 12:04 UTCMay 8, 12:39 UTC35m
2026-05-08 NOS98AQ VRN → FCO May 8, 09:30 UTCMay 8, 10:14 UTC45m
2026-05-07 NOS4723 SID → VRN May 7, 09:20 UTCMay 7, 22:35 UTC13h 15m
2026-05-05 NOS9802 - May 5, 14:25 UTCMay 5, 15:35 UTC1h 10m
2026-05-05 NOS8802 - May 5, 11:00 UTCMay 5, 12:15 UTC1h 15m
2026-05-05 NOS9801 LDE → BLQ May 5, 08:20 UTCMay 5, 09:35 UTC1h 15m
2026-05-05 NOS8801 - May 5, 04:40 UTCMay 5, 06:00 UTC1h 20m
2026-05-04 NOS1350 LPA → MXP May 4, 13:20 UTCMay 4, 16:30 UTC3h 10m
2026-05-04 NOS1350 LPA → MXP May 4, 06:00 UTCMay 4, 10:15 UTC4h 15m
2026-05-02 NOS35EW - May 2, 05:30 UTCMay 2, 14:10 UTC8h 40m
2026-05-01 NOS8807 - May 1, 18:30 UTCMay 1, 19:40 UTC1h 10m
2026-05-01 NOS9806 BLQ → LDE May 1, 16:10 UTCMay 1, 17:35 UTC1h 25m
2026-05-01 NOS8805 LDE → BLQ May 1, 13:15 UTCMay 1, 14:35 UTC1h 20m
2026-05-01 NOS9805 VRN → LDE May 1, 10:45 UTCMay 1, 12:05 UTC1h 20m
2026-04-30 NOS4357 VRN → RMF Apr 30, 07:45 UTCApr 30, 18:20 UTC10h 35m
2026-04-27 NOS1350 LPA → MXP Apr 27, 13:15 UTCApr 27, 16:45 UTC3h 30m
2026-04-27 NOS1350 LPA → MXP Apr 27, 06:00 UTCApr 27, 09:40 UTC3h 40m
2026-04-25 NOS47YJ - Apr 25, 06:10 UTCApr 25, 15:10 UTC9h 0m
2026-04-23 NOS42VW - Apr 23, 17:15 UTCApr 24, 02:10 UTC8h 55m
2026-04-23 NOS4357 VRN → RMF Apr 23, 05:10 UTCApr 23, 15:50 UTC10h 40m
2026-04-20 NOS69SQ VRN → FUE Apr 20, 06:35 UTCApr 20, 16:10 UTC9h 35m
2026-04-16 NOS4357 VRN → RMF Apr 16, 17:40 UTCApr 16, 19:10 UTC1h 30m
2026-04-16 NOS4357 VRN → RMF Apr 16, 15:45 UTCApr 16, 17:05 UTC1h 20m
2026-04-16 NOS4357 VRN → RMF Apr 16, 11:09 UTCApr 16, 11:20 UTC10m

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

Mode-S 4CA961 frequently asked

What is Mode-S code 4CA961?
4CA961 is an ICAO 24-bit transponder address. Allocated to Ireland. Assigned to EI-RZC.
Where is Mode-S 4CA961 registered?
Mode-S code 4CA961 is allocated to Ireland (IE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4CA961 broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4CA961, octal 23124541, decimal 5,024,097.
What flights does 4CA961 operate?
Mode-S 4CA961 has broadcast 20 distinct callsigns, including NOS1350, NOS4357, NOS5964, NOS1446, NOS6919.