sensors Mode-S transponder

399503

ICAO 24-bit transponder address · allocated to France

Hex
399503
Octal
16312403
Decimal
3,773,699
Country
FR
No current signal · last broadcast 7d ago
Flights observed
25
Distinct callsigns
1
Country
FR
Last broadcast
7d ago

Last known position

Most recent position reported by Mode-S 399503.

Country allocation

The ICAO 24-bit address 399503 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
EVFHFID - 25 2026-05-27

Recent flights last 25

DateFlightRouteTakeoffLandingDuration
2026-05-27 EVFHFID - May 27, 09:20 UTCMay 27, 10:20 UTC1h 0m
2026-05-27 EVFHFID - May 27, 07:45 UTCMay 27, 07:55 UTC10m
2026-05-25 EVFHFID - May 25, 16:10 UTCMay 25, 16:20 UTC10m
2026-05-25 EVFHFID - May 25, 13:00 UTCMay 25, 13:10 UTC10m
2026-05-23 EVFHFID - May 23, 07:50 UTCMay 23, 08:00 UTC10m
2026-05-14 EVFHFID - May 14, 16:00 UTCMay 14, 16:10 UTC10m
2026-05-14 EVFHFID - May 14, 15:01 UTCMay 14, 15:20 UTC20m
2026-05-12 EVFHFID - May 12, 13:15 UTCMay 12, 13:25 UTC10m
2026-05-12 EVFHFID - May 12, 12:20 UTCMay 12, 12:30 UTC10m
2026-05-09 EVFHFID - May 9, 15:55 UTCMay 9, 16:05 UTC10m
2026-05-04 EVFHFID - May 4, 12:30 UTCMay 4, 12:45 UTC15m
2026-05-01 EVFHFID - May 1, 08:50 UTCMay 1, 09:45 UTC55m
2026-04-30 EVFHFID - Apr 30, 11:35 UTCApr 30, 11:45 UTC10m
2026-04-30 EVFHFID - Apr 30, 10:45 UTCApr 30, 11:30 UTC45m
2026-04-25 EVFHFID - Apr 25, 16:30 UTCApr 25, 16:45 UTC15m
2026-04-25 EVFHFID - Apr 25, 15:20 UTCApr 25, 15:40 UTC20m
2026-04-25 EVFHFID - Apr 25, 13:05 UTCApr 25, 13:50 UTC45m
2026-04-20 EVFHFID - Apr 20, 16:35 UTCApr 20, 17:00 UTC25m
2026-04-20 EVFHFID - Apr 20, 09:30 UTCApr 20, 09:55 UTC25m
2026-04-19 EVFHFID - Apr 19, 15:10 UTCApr 19, 15:20 UTC10m
2026-04-19 EVFHFID - Apr 19, 14:25 UTCApr 19, 14:40 UTC15m
2026-04-19 EVFHFID - Apr 19, 09:50 UTCApr 19, 10:00 UTC10m
2026-04-19 EVFHFID - Apr 19, 08:30 UTCApr 19, 08:40 UTC10m
2026-04-14 EVFHFID - Apr 14, 14:55 UTCApr 14, 15:05 UTC10m
2026-04-14 EVFHFID - Apr 14, 14:00 UTCApr 14, 14:10 UTC10m

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.

Mode-S 399503 frequently asked

What is Mode-S code 399503?
399503 is an ICAO 24-bit transponder address. Allocated to France.
Where is Mode-S 399503 registered?
Mode-S code 399503 is allocated to France (FR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 399503 broadcasting right now?
No active broadcast right now. Last signal was 7d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 399503, octal 16312403, decimal 3,773,699.
What flights does 399503 operate?
Mode-S 399503 has broadcast 1 distinct callsign, including EVFHFID.