sensors Mode-S transponder

4AC9A1

ICAO 24-bit transponder address · allocated to Sweden

Currently assigned to SE-RMA · BOMBARDIER BD-100 Challenger 300

Hex
4AC9A1
Octal
22544641
Decimal
4,901,281
Country
SE
Tail
SE-RMA
Type
CL30
No current signal · last broadcast 1d ago
Flights observed
29
Distinct callsigns
2
Country
SE
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 4AC9A1.

Country allocation

The ICAO 24-bit address 4AC9A1 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
HCR10 - 27 2026-06-08
HCR010 - 2 2026-05-14

Recent flights last 29

DateFlightRouteTakeoffLandingDuration
2026-06-08 HCR10 - Jun 8, 15:15 UTCJun 8, 15:50 UTC35m
2026-06-08 HCR10 DBV → RMI Jun 8, 10:35 UTCJun 8, 11:20 UTC45m
2026-06-08 HCR10 - Jun 8, 08:20 UTCJun 8, 09:45 UTC1h 25m
2026-06-07 HCR10 ZRH → FRA Jun 7, 14:15 UTCJun 7, 14:50 UTC35m
2026-06-07 HCR10 BMA → ZRH Jun 7, 11:00 UTCJun 7, 12:55 UTC1h 55m
2026-06-07 HCR10 - Jun 7, 08:50 UTCJun 7, 10:20 UTC1h 30m
2026-06-07 HCR10 - Jun 7, 07:00 UTCJun 7, 07:50 UTC50m
2026-06-06 HCR10 - Jun 6, 11:25 UTCJun 6, 11:49 UTC25m
2026-06-04 HCR10 TNG → LBG Jun 4, 06:10 UTCJun 4, 08:25 UTC2h 15m
2026-06-03 HCR10 - Jun 3, 13:55 UTCJun 3, 14:35 UTC40m
2026-06-03 HCR10 - Jun 3, 08:25 UTCJun 3, 10:55 UTC2h 30m
2026-06-02 HCR10 - Jun 2, 18:25 UTCJun 2, 19:50 UTC1h 25m
2026-05-23 HCR10 - May 23, 10:10 UTCMay 23, 11:20 UTC1h 10m
2026-05-18 HCR10 - May 18, 12:40 UTCMay 18, 13:25 UTC45m
2026-05-18 HCR10 - May 18, 08:25 UTCMay 18, 10:05 UTC1h 40m
2026-05-18 HCR10 RKE → BRU May 18, 06:10 UTCMay 18, 07:25 UTC1h 15m
2026-05-17 HCR10 - May 17, 10:20 UTCMay 17, 12:25 UTC2h 5m
2026-05-17 HCR10 - May 17, 06:20 UTCMay 17, 07:35 UTC1h 15m
2026-05-15 HCR10 IBZ → CEQ May 15, 11:15 UTCMay 15, 12:30 UTC1h 15m
2026-05-14 HCR010 ATH → IBZ May 14, 14:05 UTCMay 14, 17:10 UTC3h 5m
2026-05-13 HCR10 - May 13, 12:25 UTCMay 13, 15:30 UTC3h 5m
2026-05-12 HCR010 IBZ → GCI May 12, 12:00 UTCMay 12, 13:40 UTC1h 40m
2026-05-10 HCR10 - May 10, 12:10 UTCMay 10, 14:09 UTC2h 0m
2026-05-03 HCR10 - May 3, 12:15 UTCMay 3, 14:10 UTC1h 55m
2026-04-25 HCR10 - Apr 25, 09:55 UTCApr 25, 11:25 UTC1h 30m
2026-04-19 HCR10 - Apr 19, 10:35 UTCApr 19, 11:50 UTC1h 15m
2026-04-13 HCR10 - Apr 13, 16:15 UTCApr 13, 16:30 UTC15m
2026-04-13 HCR10 - Apr 13, 15:50 UTCApr 13, 16:30 UTC40m
2026-04-13 HCR10 - Apr 13, 15:35 UTCApr 13, 16:15 UTC40m

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

Mode-S 4AC9A1 frequently asked

What is Mode-S code 4AC9A1?
4AC9A1 is an ICAO 24-bit transponder address. Allocated to Sweden. Assigned to SE-RMA.
Where is Mode-S 4AC9A1 registered?
Mode-S code 4AC9A1 is allocated to Sweden (SE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4AC9A1 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 4AC9A1, octal 22544641, decimal 4,901,281.
What flights does 4AC9A1 operate?
Mode-S 4AC9A1 has broadcast 2 distinct callsigns, including HCR10, HCR010.