sensors Mode-S transponder

398D46

ICAO 24-bit transponder address · allocated to France

Currently assigned to F-HDKG · DIAMOND DA-40 Club Star

Hex
398D46
Octal
16306506
Decimal
3,771,718
Country
FR
Tail
F-HDKG
Type
DA40
No current signal · last broadcast 23h ago
Flights observed
1
Distinct callsigns
1
Country
FR
Last broadcast
23h ago

Last known position

Most recent position reported by Mode-S 398D46.

Country allocation

The ICAO 24-bit address 398D46 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
FHDKG - 1 2026-04-14

Recent flights last 1

DateFlightRouteTakeoffLandingDuration
2026-04-14 FHDKG - Apr 14, 09:15 UTCApr 14, 10:25 UTC1h 10m

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

Mode-S 398D46 frequently asked

What is Mode-S code 398D46?
398D46 is an ICAO 24-bit transponder address. Allocated to France. Assigned to F-HDKG.
Where is Mode-S 398D46 registered?
Mode-S code 398D46 is allocated to France (FR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 398D46 broadcasting right now?
No active broadcast right now. Last signal was 23h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 398D46, octal 16306506, decimal 3,771,718.
What flights does 398D46 operate?
Mode-S 398D46 has broadcast 1 distinct callsign, including FHDKG.