sensors Mode-S transponder

4ACA66

ICAO 24-bit transponder address · allocated to Sweden

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

Hex
4ACA66
Octal
22545146
Decimal
4,901,478
Country
SE
Tail
SE-RSF
Type
A359
Photo of SE-RSF
No current signal · last broadcast 13h ago
Flights observed
11
Distinct callsigns
4
Country
SE
Last broadcast
13h ago

Last known position

Most recent position reported by Mode-S 4ACA66.

Country allocation

The ICAO 24-bit address 4ACA66 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 4 distinct

Callsign Airline Flights Last seen
SAS935 Scandinavian Airlines System 5 2026-04-13
SAS926 - 3 2026-04-13
SAS936 Scandinavian Airlines System 2 2026-04-14
SAS925 Scandinavian Airlines System 1 2026-04-12

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-14 SAS936 SFO → CPH Apr 14, 09:10 UTCApr 14, 10:15 UTC1h 5m
2026-04-14 SAS936 SFO → CPH Apr 14, 07:30 UTCApr 14, 08:05 UTC35m
2026-04-13 SAS935 CPH → SFO Apr 13, 19:50 UTCApr 13, 21:25 UTC1h 35m
2026-04-13 SAS935 CPH → SFO Apr 13, 18:55 UTCApr 13, 20:10 UTC1h 15m
2026-04-13 SAS935 CPH → SFO Apr 13, 12:20 UTCApr 13, 12:40 UTC20m
2026-04-13 SAS935 CPH → SFO Apr 13, 11:55 UTCApr 13, 12:40 UTC45m
2026-04-13 SAS935 CPH → SFO Apr 13, 11:40 UTCApr 13, 12:15 UTC35m
2026-04-13 SAS926 - Apr 13, 07:55 UTCApr 13, 08:20 UTC25m
2026-04-13 SAS926 IAD → CPH Apr 13, 06:30 UTCApr 13, 08:15 UTC1h 45m
2026-04-13 SAS926 IAD → CPH Apr 13, 01:00 UTCApr 13, 03:05 UTC2h 5m
2026-04-12 SAS925 CPH → IAD Apr 12, 19:10 UTCApr 12, 20:15 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 SE-RSF page for operator, model, and routing details .

Mode-S 4ACA66 frequently asked

What is Mode-S code 4ACA66?
4ACA66 is an ICAO 24-bit transponder address. Allocated to Sweden. Assigned to SE-RSF.
Where is Mode-S 4ACA66 registered?
Mode-S code 4ACA66 is allocated to Sweden (SE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4ACA66 broadcasting right now?
No active broadcast right now. Last signal was 13h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4ACA66, octal 22545146, decimal 4,901,478.
What flights does 4ACA66 operate?
Mode-S 4ACA66 has broadcast 4 distinct callsigns, including SAS935, SAS926, SAS936, SAS925.