sensors Mode-S transponder

300401

ICAO 24-bit transponder address · allocated to Italy

Currently assigned to I-NOST · AGUSTA AW-139

Hex
300401
Octal
14002001
Decimal
3,146,753
Country
IT
Tail
I-NOST
Type
A139
No current signal · last broadcast 1d ago
Flights observed
6
Distinct callsigns
1
Country
IT
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 300401.

Country allocation

The ICAO 24-bit address 300401 falls within the block assigned to Italy (IT) by ICAO Annex 10, Volume III. Every aircraft registered in Italy 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
INOST - 6 2026-04-13

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-13 INOST - Apr 13, 15:55 UTCApr 13, 16:00 UTC5m
2026-04-13 INOST - Apr 13, 15:30 UTCApr 13, 16:00 UTC30m
2026-04-13 INOST - Apr 13, 14:35 UTCApr 13, 14:55 UTC20m
2026-04-13 INOST - Apr 13, 09:35 UTCApr 13, 09:45 UTC10m
2026-04-12 INOST - Apr 12, 23:55 UTCApr 13, 00:05 UTC10m
2026-04-12 INOST - 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 I-NOST page for operator, model, and routing details .

Mode-S 300401 frequently asked

What is Mode-S code 300401?
300401 is an ICAO 24-bit transponder address. Allocated to Italy. Assigned to I-NOST.
Where is Mode-S 300401 registered?
Mode-S code 300401 is allocated to Italy (IT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 300401 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 300401, octal 14002001, decimal 3,146,753.
What flights does 300401 operate?
Mode-S 300401 has broadcast 1 distinct callsign, including INOST.