sensors Mode-S transponder

4ACA65

ICAO 24-bit transponder address · allocated to Sweden

Currently assigned to SE-RSE · AIRBUS A-350-900

Hex
4ACA65
Octal
22545145
Decimal
4,901,477
Country
SE
Tail
SE-RSE
Type
A359
Photo of SE-RSE
Broadcasting now · callsign SAS987 · 37,000 ft
Flights observed
5
Distinct callsigns
2
Country
SE
Last broadcast
14h ago

Current position

4ACA65 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 4ACA65 falls within the block assigned to Sweden (SE) by ICAO Annex 10, Volume III. Every aircraft registered in Sweden 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
SAS983 Scandinavian Airlines System 4 2026-04-13
SAS984 Scandinavian Airlines System 1 2026-04-14

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-14 SAS984 HND → CPH Apr 14, 07:50 UTCApr 14, 08:35 UTC45m
2026-04-13 SAS983 CPH → NRT Apr 13, 21:35 UTCApr 13, 23:15 UTC1h 40m
2026-04-13 SAS983 CPH → NRT Apr 13, 12:20 UTCApr 13, 14:45 UTC2h 25m
2026-04-13 SAS983 CPH → NRT Apr 13, 11:55 UTCApr 13, 14:45 UTC2h 50m
2026-04-13 SAS983 CPH → NRT Apr 13, 11:05 UTCApr 13, 12:15 UTC1h 10m

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 SE-RSE page for operator, model, and routing details .

Mode-S 4ACA65 frequently asked

What is Mode-S code 4ACA65?
4ACA65 is an ICAO 24-bit transponder address. Allocated to Sweden. Assigned to SE-RSE.
Where is Mode-S 4ACA65 registered?
Mode-S code 4ACA65 is allocated to Sweden (SE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4ACA65 broadcasting right now?
Yes. Mode-S 4ACA65 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4ACA65, octal 22545145, decimal 4,901,477.
What flights does 4ACA65 operate?
Mode-S 4ACA65 has broadcast 2 distinct callsigns, including SAS983, SAS984.