sensors Mode-S transponder

4AD959

ICAO 24-bit transponder address · allocated to Sweden

Currently assigned to SE-VJY · ROTORSPORT MTOSport

Hex
4AD959
Octal
22554531
Decimal
4,905,305
Country
SE
Tail
SE-VJY
Type
MT
No current signal · last broadcast 2h ago
Flights observed
5
Distinct callsigns
1
Country
SE
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S 4AD959.

Country allocation

The ICAO 24-bit address 4AD959 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
SEVJY - 5 2026-07-16

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-07-16 SEVJY - Jul 16, 19:05 UTCJul 16, 19:14 UTC10m
2026-06-28 SEVJY - Jun 28, 16:49 UTCJun 28, 17:19 UTC30m
2026-06-28 SEVJY - Jun 28, 15:34 UTCJun 28, 15:49 UTC15m
2026-06-25 SEVJY - Jun 25, 18:24 UTCJun 25, 18:34 UTC10m
2026-04-20 SEVJY - Apr 20, 17:40 UTCApr 20, 17:50 UTC10m

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

Mode-S 4AD959 frequently asked

What is Mode-S code 4AD959?
4AD959 is an ICAO 24-bit transponder address. Allocated to Sweden. Assigned to SE-VJY.
Where is Mode-S 4AD959 registered?
Mode-S code 4AD959 is allocated to Sweden (SE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4AD959 broadcasting right now?
No active broadcast right now. Last signal was 2h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4AD959, octal 22554531, decimal 4,905,305.
What flights does 4AD959 operate?
Mode-S 4AD959 has broadcast 1 distinct callsign, including SEVJY.