sensors Mode-S transponder

399043

ICAO 24-bit transponder address · allocated to France

Currently assigned to F-HECD · DASSAULT Falcon 7X

Hex
399043
Octal
16310103
Decimal
3,772,483
Country
FR
Tail
F-HECD
Type
FA7X
Photo of F-HECD
No current signal · last broadcast 16h ago
Flights observed
5
Distinct callsigns
1
Country
FR
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S 399043.

Country allocation

The ICAO 24-bit address 399043 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
LEA036D - 5 2026-04-14

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-14 LEA036D - Apr 14, 05:15 UTCApr 14, 06:20 UTC1h 5m
2026-04-13 LEA036D - Apr 13, 23:15 UTCApr 13, 23:40 UTC25m
2026-04-13 LEA036D - Apr 13, 00:20 UTCApr 13, 02:10 UTC1h 50m
2026-04-13 LEA036D - Apr 13, 00:05 UTCApr 13, 02:10 UTC2h 5m
2026-04-12 LEA036D - Apr 12, 18:20 UTCApr 12, 19:55 UTC1h 35m

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

Mode-S 399043 frequently asked

What is Mode-S code 399043?
399043 is an ICAO 24-bit transponder address. Allocated to France. Assigned to F-HECD.
Where is Mode-S 399043 registered?
Mode-S code 399043 is allocated to France (FR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 399043 broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 399043, octal 16310103, decimal 3,772,483.
What flights does 399043 operate?
Mode-S 399043 has broadcast 1 distinct callsign, including LEA036D.