sensors Mode-S transponder

4A35B6

ICAO 24-bit transponder address · allocated to Romania

Currently assigned to 337 · AIRBUS HELICOPTERS EC-135/635

Hex
4A35B6
Octal
22432666
Decimal
4,863,414
Country
RO
Tail
337
Type
EC35
No current signal · last broadcast 1h ago
Flights observed
7
Distinct callsigns
2
Country
RO
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S 4A35B6.

Country allocation

The ICAO 24-bit address 4A35B6 falls within the block assigned to Romania (RO) by ICAO Annex 10, Volume III. Every aircraft registered in Romania 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 2 distinct

Callsign Airline Flights Last seen
RDF43 - 5 2026-05-19
MAI337 - 2 2026-05-20

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-05-20 MAI337 - May 20, 18:40 UTCMay 20, 19:30 UTC50m
2026-05-19 MAI337 - May 19, 10:10 UTCMay 19, 10:20 UTC10m
2026-05-19 RDF43 - May 19, 08:50 UTCMay 19, 09:20 UTC30m
2026-05-19 RDF43 - May 19, 08:20 UTCMay 19, 08:40 UTC20m
2026-05-19 RDF43 - May 19, 07:55 UTCMay 19, 08:10 UTC15m
2026-05-11 RDF43 - May 11, 11:40 UTCMay 11, 11:55 UTC15m
2026-05-11 RDF43 - May 11, 11:15 UTCMay 11, 11:30 UTC15m

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 337 page for operator, model, and routing details .

Mode-S 4A35B6 frequently asked

What is Mode-S code 4A35B6?
4A35B6 is an ICAO 24-bit transponder address. Allocated to Romania. Assigned to 337.
Where is Mode-S 4A35B6 registered?
Mode-S code 4A35B6 is allocated to Romania (RO). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4A35B6 broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4A35B6, octal 22432666, decimal 4,863,414.
What flights does 4A35B6 operate?
Mode-S 4A35B6 has broadcast 2 distinct callsigns, including RDF43, MAI337.