sensors Mode-S transponder

39AC17

ICAO 24-bit transponder address · allocated to France

Currently assigned to F-HLAX · AIRBUS HELICOPTERS EC-145

Hex
39AC17
Octal
16326027
Decimal
3,779,607
Country
FR
Tail
F-HLAX
Type
EC45
Broadcasting now · callsign SAMUIDF · 425 ft
Flights observed
9
Distinct callsigns
1
Country
FR
Last broadcast
3h ago

Current position

39AC17 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 39AC17 falls within the block assigned to France (FR) by ICAO Annex 10, Volume III. Every aircraft registered in France 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
SAMUIDF - 9 2026-07-03

Recent flights last 9

DateFlightRouteTakeoffLandingDuration
2026-07-03 SAMUIDF - Jul 3, 06:20 UTCJul 3, 07:00 UTC40m
2026-07-02 SAMUIDF - Jul 2, 17:05 UTCJul 2, 17:50 UTC45m
2026-07-02 SAMUIDF - Jul 2, 15:50 UTCJul 2, 16:30 UTC40m
2026-07-02 SAMUIDF - Jul 2, 08:00 UTCJul 2, 08:20 UTC20m
2026-07-02 SAMUIDF - Jul 2, 07:05 UTCJul 2, 07:15 UTC10m
2026-07-02 SAMUIDF - Jul 2, 05:40 UTCJul 2, 06:20 UTC40m
2026-06-26 SAMUIDF - Jun 26, 11:45 UTCJun 26, 12:34 UTC50m
2026-06-26 SAMUIDF - Jun 26, 08:34 UTCJun 26, 09:14 UTC40m
2026-06-25 SAMUIDF - Jun 25, 15:40 UTCJun 25, 16:55 UTC1h 15m

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 F-HLAX page for operator, model, and routing details .

Mode-S 39AC17 frequently asked

What is Mode-S code 39AC17?
39AC17 is an ICAO 24-bit transponder address. Allocated to France. Assigned to F-HLAX.
Where is Mode-S 39AC17 registered?
Mode-S code 39AC17 is allocated to France (FR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 39AC17 broadcasting right now?
Yes. Mode-S 39AC17 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 39AC17, octal 16326027, decimal 3,779,607.
What flights does 39AC17 operate?
Mode-S 39AC17 has broadcast 1 distinct callsign, including SAMUIDF.