sensors Mode-S transponder

4CAD91

ICAO 24-bit transponder address · allocated to Ireland

Currently assigned to EI-SCA · AIRBUS A-320neo

Hex
4CAD91
Octal
23126621
Decimal
5,025,169
Country
IE
Tail
EI-SCA
Type
A20N
No current signal · last broadcast 15h ago
Flights observed
14
Distinct callsigns
9
Country
IE
Last broadcast
15h ago

Last known position

Most recent position reported by Mode-S 4CAD91.

Country allocation

The ICAO 24-bit address 4CAD91 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 9 distinct

Callsign Airline Flights Last seen
SAS51D - 3 2026-04-13
SAS31B Scandinavian Airlines System 3 2026-04-13
SAS1555 - 2 2026-04-13
SAS7934 - 1 2026-04-12
SAS77A - 1 2026-04-14
SAS589 - 1 2026-04-14
SAS187 - 1 2026-04-13
SAS1556 - 1 2026-04-13
SAS128 - 1 2026-04-13

Recent flights last 14

DateFlightRouteTakeoffLandingDuration
2026-04-14 SAS77A - Apr 14, 09:50 UTCApr 14, 11:05 UTC1h 15m
2026-04-14 SAS589 - Apr 14, 07:00 UTCApr 14, 07:10 UTC10m
2026-04-13 SAS187 - Apr 13, 20:05 UTCApr 13, 20:10 UTC5m
2026-04-13 SAS1556 - Apr 13, 17:35 UTCApr 13, 19:05 UTC1h 30m
2026-04-13 SAS1555 - Apr 13, 15:50 UTCApr 13, 16:10 UTC20m
2026-04-13 SAS1555 ARN → AMS Apr 13, 14:20 UTCApr 13, 16:10 UTC1h 50m
2026-04-13 SAS51D - Apr 13, 12:20 UTCApr 13, 13:10 UTC50m
2026-04-13 SAS51D - Apr 13, 11:55 UTCApr 13, 13:10 UTC1h 15m
2026-04-13 SAS51D - Apr 13, 11:00 UTCApr 13, 12:15 UTC1h 15m
2026-04-13 SAS31B ARN → DUB Apr 13, 08:20 UTCApr 13, 09:45 UTC1h 25m
2026-04-13 SAS31B ARN → DUB Apr 13, 07:55 UTCApr 13, 09:45 UTC1h 50m
2026-04-13 SAS31B ARN → DUB Apr 13, 07:20 UTCApr 13, 08:15 UTC55m
2026-04-13 SAS128 - Apr 13, 05:10 UTCApr 13, 06:05 UTC55m
2026-04-12 SAS7934 - Apr 12, 17:15 UTCApr 12, 19:55 UTC2h 40m

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

Mode-S 4CAD91 frequently asked

What is Mode-S code 4CAD91?
4CAD91 is an ICAO 24-bit transponder address. Allocated to Ireland. Assigned to EI-SCA.
Where is Mode-S 4CAD91 registered?
Mode-S code 4CAD91 is allocated to Ireland (IE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4CAD91 broadcasting right now?
No active broadcast right now. Last signal was 15h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4CAD91, octal 23126621, decimal 5,025,169.
What flights does 4CAD91 operate?
Mode-S 4CAD91 has broadcast 9 distinct callsigns, including SAS51D, SAS31B, SAS1555, SAS7934, SAS77A.