sensors Mode-S transponder

4CA9E7

ICAO 24-bit transponder address · allocated to Ireland

Currently assigned to EI-NUA · BOEING 787-9 Dreamliner

Hex
4CA9E7
Octal
23124747
Decimal
5,024,231
Country
IE
Tail
EI-NUA
Type
B789
No current signal · last broadcast 21h ago
Flights observed
6
Distinct callsigns
2
Country
IE
Last broadcast
21h ago

Last known position

Most recent position reported by Mode-S 4CA9E7.

Country allocation

The ICAO 24-bit address 4CA9E7 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 2 distinct

Callsign Airline Flights Last seen
NOS126 Neos 4 2026-04-13
NOS127 - 2 2026-04-14

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-14 NOS127 - Apr 14, 07:50 UTCApr 14, 08:05 UTC15m
2026-04-14 NOS127 - Apr 14, 05:45 UTCApr 14, 06:20 UTC35m
2026-04-13 NOS126 BRQ → HKT Apr 13, 21:35 UTCApr 13, 23:35 UTC2h 0m
2026-04-13 NOS126 BRQ → HKT Apr 13, 16:15 UTCApr 13, 18:50 UTC2h 35m
2026-04-13 NOS126 BRQ → HKT Apr 13, 15:50 UTCApr 13, 18:50 UTC3h 0m
2026-04-13 NOS126 BRQ → HKT Apr 13, 15:10 UTCApr 13, 16:15 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-NUA page for operator, model, and routing details .

Mode-S 4CA9E7 frequently asked

What is Mode-S code 4CA9E7?
4CA9E7 is an ICAO 24-bit transponder address. Allocated to Ireland. Assigned to EI-NUA.
Where is Mode-S 4CA9E7 registered?
Mode-S code 4CA9E7 is allocated to Ireland (IE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4CA9E7 broadcasting right now?
No active broadcast right now. Last signal was 21h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4CA9E7, octal 23124747, decimal 5,024,231.
What flights does 4CA9E7 operate?
Mode-S 4CA9E7 has broadcast 2 distinct callsigns, including NOS126, NOS127.