sensors Mode-S transponder

4ACB23

ICAO 24-bit transponder address · allocated to Sweden

Currently assigned to SE-RYC · BOEING 737 MAX 8

Hex
4ACB23
Octal
22545443
Decimal
4,901,667
Country
SE
Tail
SE-RYC
Type
B38M
No current signal · last broadcast 16h ago
Flights observed
12
Distinct callsigns
8
Country
SE
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S 4ACB23.

Country allocation

The ICAO 24-bit address 4ACB23 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 8 distinct

Callsign Airline Flights Last seen
NSZ3KQ - 3 2026-04-13
NSZ8UK - 2 2026-04-13
NSZ8KC Norwegian Air Sweden AOC 2 2026-04-14
NSZ5075 - 1 2026-04-12
NSZ5074 - 1 2026-04-12
NSZ5071 Norwegian Air Sweden AOC 1 2026-04-13
NSZ5070 - 1 2026-04-13
NSZ5051 Norwegian Air Sweden AOC 1 2026-04-14

Recent flights last 12

DateFlightRouteTakeoffLandingDuration
2026-04-14 NSZ5051 ARN → AGP Apr 14, 09:50 UTCApr 14, 11:05 UTC1h 15m
2026-04-14 NSZ8KC AGP → ARN Apr 14, 07:10 UTCApr 14, 08:45 UTC1h 35m
2026-04-14 NSZ8KC AGP → ARN Apr 14, 05:15 UTCApr 14, 07:10 UTC1h 55m
2026-04-13 NSZ8UK - Apr 13, 19:50 UTCApr 13, 21:30 UTC1h 40m
2026-04-13 NSZ8UK - Apr 13, 17:45 UTCApr 13, 20:10 UTC2h 25m
2026-04-13 NSZ3KQ - Apr 13, 16:15 UTCApr 13, 16:45 UTC30m
2026-04-13 NSZ3KQ - Apr 13, 15:50 UTCApr 13, 16:45 UTC55m
2026-04-13 NSZ3KQ - Apr 13, 13:20 UTCApr 13, 16:15 UTC2h 55m
2026-04-13 NSZ5071 CPH → AGP Apr 13, 08:50 UTCApr 13, 12:00 UTC3h 10m
2026-04-13 NSZ5070 - Apr 13, 04:25 UTCApr 13, 07:35 UTC3h 10m
2026-04-12 NSZ5075 - Apr 12, 18:25 UTCApr 12, 20:15 UTC1h 50m
2026-04-12 NSZ5074 - Apr 12, 17:15 UTCApr 12, 17:35 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-RYC page for operator, model, and routing details .

Mode-S 4ACB23 frequently asked

What is Mode-S code 4ACB23?
4ACB23 is an ICAO 24-bit transponder address. Allocated to Sweden. Assigned to SE-RYC.
Where is Mode-S 4ACB23 registered?
Mode-S code 4ACB23 is allocated to Sweden (SE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4ACB23 broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4ACB23, octal 22545443, decimal 4,901,667.
What flights does 4ACB23 operate?
Mode-S 4ACB23 has broadcast 8 distinct callsigns, including NSZ3KQ, NSZ8UK, NSZ8KC, NSZ5075, NSZ5074.