sensors Mode-S transponder

4ACA63

ICAO 24-bit transponder address · allocated to Sweden

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

Hex
4ACA63
Octal
22545143
Decimal
4,901,475
Country
SE
Tail
SE-RSC
Type
A359
Photo of SE-RSC
Broadcasting now · callsign SAS983 · 20,550 ft
Flights observed
5
Distinct callsigns
2
Country
SE
Last broadcast
23h ago

Current position

4ACA63 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 4ACA63 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
SAS987 - 3 2026-04-13
SAS988 - 2 2026-04-13

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-13 SAS988 - Apr 13, 20:15 UTCApr 13, 23:40 UTC3h 25m
2026-04-13 SAS988 ICN → CPH Apr 13, 14:55 UTCApr 13, 15:15 UTC20m
2026-04-13 SAS987 - Apr 13, 09:00 UTCApr 13, 09:15 UTC15m
2026-04-13 SAS987 - Apr 13, 00:20 UTCApr 13, 01:55 UTC1h 35m
2026-04-12 SAS987 - Apr 12, 23:55 UTCApr 13, 01:55 UTC2h 0m

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

Mode-S 4ACA63 frequently asked

What is Mode-S code 4ACA63?
4ACA63 is an ICAO 24-bit transponder address. Allocated to Sweden. Assigned to SE-RSC.
Where is Mode-S 4ACA63 registered?
Mode-S code 4ACA63 is allocated to Sweden (SE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4ACA63 broadcasting right now?
Yes. Mode-S 4ACA63 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4ACA63, octal 22545143, decimal 4,901,475.
What flights does 4ACA63 operate?
Mode-S 4ACA63 has broadcast 2 distinct callsigns, including SAS987, SAS988.