sensors Mode-S transponder

399B0C

ICAO 24-bit transponder address · allocated to France

Currently assigned to F-HGYM · EMBRAER ERJ-145

Hex
399B0C
Octal
16315414
Decimal
3,775,244
Country
FR
Tail
F-HGYM
Type
E145
No current signal · last broadcast 2h ago
Flights observed
3
Distinct callsigns
3
Country
FR
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S 399B0C.

Country allocation

The ICAO 24-bit address 399B0C 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 3 distinct

Callsign Airline Flights Last seen
AEH242 - 1 2026-04-18
AEH241 Aviaexpress 1 2026-04-17
AEH028F - 1 2026-04-13

Recent flights last 3

DateFlightRouteTakeoffLandingDuration
2026-04-18 AEH242 CWL → LBG Apr 18, 19:25 UTCApr 18, 20:30 UTC1h 5m
2026-04-17 AEH241 WRT → WRT Apr 17, 09:20 UTCApr 17, 10:25 UTC1h 5m
2026-04-13 AEH028F - Apr 13, 09:20 UTCApr 13, 09:55 UTC35m

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

Mode-S 399B0C frequently asked

What is Mode-S code 399B0C?
399B0C is an ICAO 24-bit transponder address. Allocated to France. Assigned to F-HGYM.
Where is Mode-S 399B0C registered?
Mode-S code 399B0C is allocated to France (FR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 399B0C broadcasting right now?
No active broadcast right now. Last signal was 2h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 399B0C, octal 16315414, decimal 3,775,244.
What flights does 399B0C operate?
Mode-S 399B0C has broadcast 3 distinct callsigns, including AEH242, AEH241, AEH028F.