sensors Mode-S transponder

3475C9

ICAO 24-bit transponder address · allocated to Spain

Currently assigned to EC-OCT · AIRBUS A-321

Hex
3475C9
Octal
15072711
Decimal
3,438,025
Country
ES
Tail
EC-OCT
Type
A321
No current signal · last broadcast 1d ago
Flights observed
7
Distinct callsigns
6
Country
ES
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 3475C9.

Country allocation

The ICAO 24-bit address 3475C9 falls within the block assigned to Spain (ES) by ICAO Annex 10, Volume III. Every aircraft registered in Spain 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 6 distinct

Callsign Airline Flights Last seen
RZO171 - 2 2026-04-13
RZO174 - 1 2026-04-12
RZO173 - 1 2026-04-12
RZO172 - 1 2026-04-13
RZO0174 - 1 2026-04-13
RZO0173 - 1 2026-04-13

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-13 RZO0173 - Apr 13, 19:05 UTCApr 13, 19:40 UTC35m
2026-04-13 RZO0174 - Apr 13, 16:55 UTCApr 13, 17:30 UTC35m
2026-04-13 RZO171 - Apr 13, 14:10 UTCApr 13, 14:20 UTC10m
2026-04-13 RZO171 - Apr 13, 12:20 UTCApr 13, 12:50 UTC30m
2026-04-13 RZO172 - Apr 13, 09:55 UTCApr 13, 10:35 UTC40m
2026-04-12 RZO173 - Apr 12, 20:00 UTCApr 12, 20:15 UTC15m
2026-04-12 RZO174 - Apr 12, 17:40 UTCApr 12, 18:20 UTC40m

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 EC-OCT page for operator, model, and routing details .

Mode-S 3475C9 frequently asked

What is Mode-S code 3475C9?
3475C9 is an ICAO 24-bit transponder address. Allocated to Spain. Assigned to EC-OCT.
Where is Mode-S 3475C9 registered?
Mode-S code 3475C9 is allocated to Spain (ES). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 3475C9 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 3475C9, octal 15072711, decimal 3,438,025.
What flights does 3475C9 operate?
Mode-S 3475C9 has broadcast 6 distinct callsigns, including RZO171, RZO174, RZO173, RZO172, RZO0174.