sensors Mode-S transponder

4AC9AB

ICAO 24-bit transponder address · allocated to Sweden

Currently assigned to SE-RMK · BOMBARDIER BD-700 Global 6000/6500

Hex
4AC9AB
Octal
22544653
Decimal
4,901,291
Country
SE
Tail
SE-RMK
Type
GLEX
No current signal · last broadcast 1d ago
Flights observed
34
Distinct callsigns
1
Country
SE
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 4AC9AB.

Country allocation

The ICAO 24-bit address 4AC9AB 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 1 distinct

Callsign Airline Flights Last seen
SERMK - 34 2026-06-01

Recent flights last 34

DateFlightRouteTakeoffLandingDuration
2026-06-01 SERMK - Jun 1, 03:10 UTCJun 1, 05:30 UTC2h 20m
2026-05-30 SERMK - May 30, 15:10 UTCMay 31, 00:55 UTC9h 45m
2026-05-28 SERMK - May 28, 17:00 UTCMay 29, 03:00 UTC10h 0m
2026-05-28 SERMK - May 28, 13:40 UTCMay 28, 15:45 UTC2h 5m
2026-05-27 SERMK - May 27, 22:25 UTCMay 28, 05:00 UTC6h 35m
2026-05-26 SERMK - May 26, 16:55 UTCMay 27, 00:10 UTC7h 15m
2026-05-26 SERMK - May 26, 14:20 UTCMay 26, 14:45 UTC25m
2026-05-21 SERMK - May 21, 22:00 UTCMay 21, 22:25 UTC25m
2026-05-21 SERMK - May 21, 19:50 UTCMay 21, 21:20 UTC1h 30m
2026-05-20 SERMK LPI → PRG May 20, 15:20 UTCMay 20, 16:40 UTC1h 20m
2026-05-20 SERMK - May 20, 12:00 UTCMay 20, 12:25 UTC25m
2026-05-20 SERMK - May 20, 09:55 UTCMay 20, 10:15 UTC20m
2026-05-18 SERMK - May 18, 16:10 UTCMay 18, 16:35 UTC25m
2026-05-18 SERMK GOT → BMA May 18, 14:55 UTCMay 18, 15:35 UTC40m
2026-05-17 SERMK - May 17, 22:15 UTCMay 17, 22:55 UTC40m
2026-05-17 SERMK - May 17, 21:01 UTCMay 17, 21:40 UTC40m
2026-05-16 SERMK - May 16, 13:01 UTCMay 16, 13:41 UTC40m
2026-05-16 SERMK LPI → BMA May 16, 11:21 UTCMay 16, 11:51 UTC30m
2026-05-12 SERMK - May 12, 17:55 UTCMay 12, 18:15 UTC20m
2026-05-12 SERMK BRU → BMA May 12, 15:25 UTCMay 12, 17:05 UTC1h 40m
2026-05-12 SERMK - May 12, 08:55 UTCMay 12, 10:40 UTC1h 45m
2026-05-11 SERMK - May 11, 12:50 UTCMay 11, 16:05 UTC3h 15m
2026-05-11 SERMK - May 11, 11:10 UTCMay 11, 11:35 UTC25m
2026-04-30 SERMK - Apr 30, 07:30 UTCApr 30, 08:45 UTC1h 15m
2026-04-21 SERMK - Apr 21, 11:35 UTCApr 21, 12:01 UTC25m
2026-04-17 SERMK - Apr 17, 13:25 UTCApr 17, 14:20 UTC55m
2026-04-17 SERMK - Apr 17, 11:25 UTCApr 17, 12:40 UTC1h 15m
2026-04-17 SERMK - Apr 17, 07:20 UTCApr 17, 07:40 UTC20m
2026-04-17 SERMK - Apr 17, 05:35 UTCApr 17, 07:15 UTC1h 40m
2026-04-16 SERMK - Apr 16, 17:15 UTCApr 16, 17:25 UTC10m
2026-04-16 SERMK - Apr 16, 15:55 UTCApr 16, 17:10 UTC1h 15m
2026-04-16 SERMK - Apr 16, 11:09 UTCApr 16, 12:05 UTC55m
2026-04-16 SERMK - Apr 16, 10:34 UTCApr 16, 11:04 UTC30m
2026-04-16 SERMK - Apr 16, 09:10 UTCApr 16, 09:29 UTC20m

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

Mode-S 4AC9AB frequently asked

What is Mode-S code 4AC9AB?
4AC9AB is an ICAO 24-bit transponder address. Allocated to Sweden. Assigned to SE-RMK.
Where is Mode-S 4AC9AB registered?
Mode-S code 4AC9AB is allocated to Sweden (SE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4AC9AB broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4AC9AB, octal 22544653, decimal 4,901,291.
What flights does 4AC9AB operate?
Mode-S 4AC9AB has broadcast 1 distinct callsign, including SERMK.