Apparatus

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sensors Mode-S transponder

4ACA81

ICAO 24-bit transponder address · allocated to Sweden

Currently assigned to SE-RTA · BOEING 737 MAX 8

Hex
4ACA81
Octal
22545201
Decimal
4,901,505
Country
SE
Tail
SE-RTA
Type
B38M
Broadcasting now · callsign NSZ4317 · 37,000 ft
Flights observed
520
Distinct callsigns
20
Country
SE
Last broadcast
Jul 26, 21:40 UTC

Current position

4ACA81 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 4ACA81 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 20 distinct

Callsign Airline Flights Last seen
NSZ4508 Norwegian Air Sweden AOC 7 2026-07-26
NSZ4507 Norwegian Air Sweden AOC 7 2026-07-26
NSZ2616 Norwegian Air Sweden AOC 7 2026-05-03
NSZ6RD Norwegian Air Sweden AOC 6 2026-07-26
NSZ5NE Norwegian Air Sweden AOC 6 2026-07-23
NSZ56J Norwegian Air Sweden AOC 6 2026-07-23
NSZ2ES Norwegian Air Sweden AOC 6 2026-07-22
NSZ2767 Norwegian Air Sweden AOC 6 2026-07-24
NSZ2766 Norwegian Air Sweden AOC 6 2026-07-24
NSZ2613 Norwegian Air Sweden AOC 6 2026-07-23
NSZ8YC Norwegian Air Sweden AOC 5 2026-05-03
NSZ6LA - 5 2026-07-09
NSZ5WU - 5 2026-07-09
NSZ51M Norwegian Air Sweden AOC 5 2026-07-20
NSZ4354 Norwegian Air Sweden AOC 5 2026-07-20
NSZ4353 Norwegian Air Sweden AOC 5 2026-07-20
NSZ2TH Norwegian Air Sweden AOC 5 2026-05-03
NSZ2913 Norwegian Air Sweden AOC 5 2026-05-20
NSZ2615 Norwegian Air Sweden AOC 5 2026-07-24
NSZ9WP Norwegian Air Sweden AOC 4 2026-05-20

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 NSZ4508 BER → ARN Jul 26, 20:15 UTCJul 26, 21:35 UTC1h 20m
2026-07-26 NSZ4507 ARN → BER Jul 26, 18:05 UTCJul 26, 19:20 UTC1h 15m
2026-07-26 NSZ4502 MUC → ARN Jul 26, 15:35 UTCJul 26, 17:15 UTC1h 40m
2026-07-26 NSZ4501 ARN → MUC Jul 26, 12:35 UTCJul 26, 14:30 UTC1h 55m
2026-07-26 NSZ2633 KRK → ARN Jul 26, 09:45 UTCJul 26, 11:20 UTC1h 35m
2026-07-26 NSZ2632 ARN → KRK Jul 26, 07:10 UTCJul 26, 08:50 UTC1h 40m
2026-07-26 NSZ6RD HEL → ARN Jul 26, 05:15 UTCJul 26, 06:00 UTC45m
2026-07-25 NSZ2911 ALC → HEL Jul 25, 19:40 UTCJul 25, 23:20 UTC3h 40m
2026-07-25 NSZ2910 HEL → ALC Jul 25, 14:20 UTCJul 25, 18:30 UTC4h 10m
2026-07-25 NSZ2829 TIV → HEL Jul 25, 04:35 UTCJul 25, 13:00 UTC8h 25m
2026-07-24 NSZ2529 RVN → HEL Jul 24, 18:15 UTCJul 24, 19:05 UTC50m
2026-07-24 NSZ2528 HEL → RVN Jul 24, 16:00 UTCJul 24, 16:45 UTC45m
2026-07-24 NSZ2615 ARN → HEL Jul 24, 14:30 UTCJul 24, 15:10 UTC40m
2026-07-24 NSZ4BP HEL → ARN Jul 24, 12:55 UTCJul 24, 13:40 UTC45m
2026-07-24 NSZ2767 LGW → HEL Jul 24, 09:15 UTCJul 24, 11:45 UTC2h 30m
2026-07-24 NSZ2766 HEL → LGW Jul 24, 05:20 UTCJul 24, 08:00 UTC2h 40m
2026-07-23 NSZ2941 BGY → HEL Jul 23, 18:30 UTCJul 23, 21:15 UTC2h 45m
2026-07-23 NSZ2940 HEL → BGY Jul 23, 15:10 UTCJul 23, 17:35 UTC2h 25m
2026-07-23 NSZ2613 ARN → HEL Jul 23, 13:15 UTCJul 23, 14:00 UTC45m
2026-07-23 NSZ56J FCO → ARN Jul 23, 09:30 UTCJul 23, 12:10 UTC2h 40m
2026-07-23 NSZ5NE ARN → FCO Jul 23, 05:10 UTCJul 23, 07:40 UTC2h 30m
2026-07-22 NSZ4382 RHO → ARN Jul 22, 23:25 UTCJul 22, 23:40 UTC15m
2026-07-22 NSZ4382 RHO → ARN Jul 22, 20:00 UTCJul 22, 22:25 UTC2h 25m
2026-07-22 NSZ4381 ARN → RHO Jul 22, 14:15 UTCJul 22, 17:50 UTC3h 35m
2026-07-22 NSZ2ES LGW → ARN Jul 22, 11:10 UTCJul 22, 12:50 UTC1h 40m
2026-07-21 NSZ4344 SJJ → ARN Jul 21, 20:30 UTCJul 21, 22:55 UTC2h 25m
2026-07-21 NSZ4343 ARN → SJJ Jul 21, 16:55 UTCJul 21, 19:05 UTC2h 10m
2026-07-21 NSZ4556 VNO → ARN Jul 21, 14:45 UTCJul 21, 15:55 UTC1h 10m
2026-07-21 NSZ4555 ARN → VNO Jul 21, 12:45 UTCJul 21, 13:50 UTC1h 5m
2026-07-21 NSZ6YF SPU → ARN Jul 21, 09:25 UTCJul 21, 11:50 UTC2h 25m
2026-07-21 NSZ5PK ARN → SPU Jul 21, 05:40 UTCJul 21, 08:00 UTC2h 20m
2026-07-20 NSZ4354 AMS → ARN Jul 20, 20:20 UTCJul 20, 21:55 UTC1h 35m
2026-07-20 NSZ4353 ARN → AMS Jul 20, 17:25 UTCJul 20, 19:05 UTC1h 40m
2026-07-20 NSZ44L - Jul 20, 15:25 UTCJul 20, 16:30 UTC1h 5m
2026-07-20 NSZ43E - Jul 20, 13:40 UTCJul 20, 14:35 UTC55m
2026-07-20 NSZ2ES LGW → ARN Jul 20, 10:25 UTCJul 20, 12:30 UTC2h 5m
2026-07-20 NSZ51M ARN → LGW Jul 20, 07:10 UTCJul 20, 09:20 UTC2h 10m
2026-07-19 NSZ4508 - Jul 19, 20:40 UTCJul 19, 21:55 UTC1h 15m
2026-07-19 NSZ4507 ARN → BER Jul 19, 18:40 UTCJul 19, 19:55 UTC1h 15m
2026-07-19 NSZ5DM - Jul 19, 13:25 UTCJul 19, 17:15 UTC3h 50m
2026-07-19 NSZ5071 - Jul 19, 08:50 UTCJul 19, 12:05 UTC3h 15m
2026-07-19 NSZ5070 AGP → CPH Jul 19, 04:35 UTCJul 19, 07:40 UTC3h 5m
2026-07-18 NSZ5123 HEL → AGP Jul 18, 19:00 UTCJul 18, 23:35 UTC4h 35m
2026-07-18 NSZ9ED AGP → HEL Jul 18, 13:45 UTCJul 18, 17:50 UTC4h 5m
2026-07-18 NSZ5071 - Jul 18, 08:40 UTCJul 18, 12:05 UTC3h 25m
2026-07-18 NSZ5070 AGP → CPH Jul 18, 04:25 UTCJul 18, 07:30 UTC3h 5m
2026-07-17 NSZ9YB - Jul 17, 19:40 UTCJul 17, 23:00 UTC3h 20m
2026-07-17 NSZ5074 - Jul 17, 15:05 UTCJul 17, 18:19 UTC3h 15m
2026-07-17 NSZ5051 - Jul 17, 09:50 UTCJul 17, 14:00 UTC4h 10m
2026-07-17 NSZ38K - Jul 17, 07:14 UTCJul 17, 08:15 UTC1h 0m

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

Mode-S 4ACA81 frequently asked

What is Mode-S code 4ACA81?
4ACA81 is an ICAO 24-bit transponder address. Allocated to Sweden. Assigned to SE-RTA.
Where is Mode-S 4ACA81 registered?
Mode-S code 4ACA81 is allocated to Sweden (SE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4ACA81 broadcasting right now?
Yes. Mode-S 4ACA81 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4ACA81, octal 22545201, decimal 4,901,505.
What flights does 4ACA81 operate?
Mode-S 4ACA81 has broadcast 20 distinct callsigns, including NSZ4508, NSZ4507, NSZ2616, NSZ6RD, NSZ5NE.