sensors Mode-S transponder

4AC9EF

ICAO 24-bit transponder address · allocated to Sweden

Currently assigned to SE-ROO · AIRBUS A-320neo

Hex
4AC9EF
Octal
22544757
Decimal
4,901,359
Country
SE
Tail
SE-ROO
Type
A20N
Photo of SE-ROO
No current signal · last broadcast 13h ago
Flights observed
18
Distinct callsigns
12
Country
SE
Last broadcast
13h ago

Last known position

Most recent position reported by Mode-S 4AC9EF.

Country allocation

The ICAO 24-bit address 4AC9EF 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 12 distinct

Callsign Airline Flights Last seen
SAS56H Scandinavian Airlines System 3 2026-04-13
SAS87Y - 2 2026-04-13
SAS792 Scandinavian Airlines System 2 2026-04-14
SAS28K - 2 2026-04-13
SAS1415 - 2 2026-04-13
SAS791 Scandinavian Airlines System 1 2026-04-14
SAS62L - 1 2026-04-13
SAS62F - 1 2026-04-12
SAS42R - 1 2026-04-13
SAS2864 Scandinavian Airlines System 1 2026-04-14
SAS2551 - 1 2026-04-13
SAS2034 - 1 2026-04-12

Recent flights last 18

DateFlightRouteTakeoffLandingDuration
2026-04-14 SAS2864 CPH → BGO Apr 14, 10:50 UTCApr 14, 11:05 UTC15m
2026-04-14 SAS792 CPH → NCE Apr 14, 09:10 UTCApr 14, 09:20 UTC10m
2026-04-14 SAS792 CPH → NCE Apr 14, 07:25 UTCApr 14, 09:05 UTC1h 40m
2026-04-14 SAS791 NCE → CPH Apr 14, 05:15 UTCApr 14, 06:25 UTC1h 10m
2026-04-13 SAS28K - Apr 13, 19:50 UTCApr 13, 20:10 UTC20m
2026-04-13 SAS28K - Apr 13, 18:30 UTCApr 13, 20:10 UTC1h 40m
2026-04-13 SAS56H CPH → GVA Apr 13, 16:15 UTCApr 13, 17:25 UTC1h 10m
2026-04-13 SAS56H CPH → GVA Apr 13, 15:50 UTCApr 13, 17:25 UTC1h 35m
2026-04-13 SAS56H CPH → GVA Apr 13, 15:40 UTCApr 13, 16:15 UTC35m
2026-04-13 SAS42R - Apr 13, 13:35 UTCApr 13, 14:35 UTC1h 0m
2026-04-13 SAS87Y - Apr 13, 11:55 UTCApr 13, 12:05 UTC10m
2026-04-13 SAS87Y CPH → AMS Apr 13, 10:55 UTCApr 13, 12:05 UTC1h 10m
2026-04-13 SAS62L - Apr 13, 08:50 UTCApr 13, 09:55 UTC1h 5m
2026-04-13 SAS2551 - Apr 13, 06:30 UTCApr 13, 07:35 UTC1h 5m
2026-04-13 SAS1415 - Apr 13, 04:20 UTCApr 13, 05:10 UTC50m
2026-04-13 SAS1415 - Apr 13, 04:10 UTCApr 13, 04:15 UTC5m
2026-04-12 SAS2034 - Apr 12, 18:50 UTCApr 12, 19:20 UTC30m
2026-04-12 SAS62F - Apr 12, 17:15 UTCApr 12, 18:00 UTC45m

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

Mode-S 4AC9EF frequently asked

What is Mode-S code 4AC9EF?
4AC9EF is an ICAO 24-bit transponder address. Allocated to Sweden. Assigned to SE-ROO.
Where is Mode-S 4AC9EF registered?
Mode-S code 4AC9EF is allocated to Sweden (SE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4AC9EF 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 4AC9EF, octal 22544757, decimal 4,901,359.
What flights does 4AC9EF operate?
Mode-S 4AC9EF has broadcast 12 distinct callsigns, including SAS56H, SAS87Y, SAS792, SAS28K, SAS1415.