sensors Mode-S transponder

4ACA12

ICAO 24-bit transponder address · allocated to Sweden

Currently assigned to SE-RPR · BOEING 737-800

Hex
4ACA12
Octal
22545022
Decimal
4,901,394
Country
SE
Tail
SE-RPR
Type
B738
No current signal · last broadcast 12h ago
Flights observed
11
Distinct callsigns
9
Country
SE
Last broadcast
12h ago

Last known position

Most recent position reported by Mode-S 4ACA12.

Country allocation

The ICAO 24-bit address 4ACA12 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 9 distinct

Callsign Airline Flights Last seen
NSZ3944 Norwegian Air Sweden AOC 2 2026-04-14
NSZ3084 Norwegian Air Sweden AOC 2 2026-04-13
NSZ8YZ - 1 2026-04-13
NSZ4508 - 1 2026-04-12
NSZ3629 - 1 2026-04-13
NSZ3628 - 1 2026-04-13
NSZ3093 - 1 2026-04-13
NSZ3089 - 1 2026-04-13
NSZ2NZ - 1 2026-04-13

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-14 NSZ3944 AAL → FNC Apr 14, 09:10 UTCApr 14, 10:35 UTC1h 25m
2026-04-14 NSZ3944 AAL → FNC Apr 14, 07:10 UTCApr 14, 09:05 UTC1h 55m
2026-04-13 NSZ2NZ - Apr 13, 17:15 UTCApr 13, 17:40 UTC25m
2026-04-13 NSZ3093 - Apr 13, 15:50 UTCApr 13, 16:15 UTC25m
2026-04-13 NSZ8YZ - Apr 13, 14:45 UTCApr 13, 15:15 UTC30m
2026-04-13 NSZ3089 - Apr 13, 13:30 UTCApr 13, 14:00 UTC30m
2026-04-13 NSZ3084 CPH → AAL Apr 13, 12:20 UTCApr 13, 12:35 UTC15m
2026-04-13 NSZ3084 CPH → AAL Apr 13, 12:05 UTCApr 13, 12:15 UTC10m
2026-04-13 NSZ3629 - Apr 13, 09:15 UTCApr 13, 11:10 UTC1h 55m
2026-04-13 NSZ3628 - Apr 13, 05:50 UTCApr 13, 07:55 UTC2h 5m
2026-04-12 NSZ4508 BER → ARN Apr 12, 18:10 UTCApr 12, 19:25 UTC1h 15m

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

Mode-S 4ACA12 frequently asked

What is Mode-S code 4ACA12?
4ACA12 is an ICAO 24-bit transponder address. Allocated to Sweden. Assigned to SE-RPR.
Where is Mode-S 4ACA12 registered?
Mode-S code 4ACA12 is allocated to Sweden (SE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4ACA12 broadcasting right now?
No active broadcast right now. Last signal was 12h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4ACA12, octal 22545022, decimal 4,901,394.
What flights does 4ACA12 operate?
Mode-S 4ACA12 has broadcast 9 distinct callsigns, including NSZ3944, NSZ3084, NSZ8YZ, NSZ4508, NSZ3629.