sensors Mode-S transponder

398E49

ICAO 24-bit transponder address · allocated to France

Currently assigned to F-HDSJ · AIRBUS A-319

Hex
398E49
Octal
16307111
Decimal
3,771,977
Country
FR
Tail
F-HDSJ
Type
A319
No current signal · last broadcast 3h ago
Flights observed
5
Distinct callsigns
4
Country
FR
Last broadcast
3h ago

Last known position

Most recent position reported by Mode-S 398E49.

Country allocation

The ICAO 24-bit address 398E49 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 4 distinct

Callsign Airline Flights Last seen
AIA491 - 2 2026-07-12
FHDSJ - 1 2026-07-10
AIA491F - 1 2026-07-12
AIA490F - 1 2026-07-11

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-07-12 AIA491F - Jul 12, 14:35 UTCJul 12, 16:20 UTC1h 45m
2026-07-12 AIA491 - Jul 12, 08:50 UTCJul 12, 13:10 UTC4h 20m
2026-07-11 AIA491 - Jul 11, 10:20 UTCJul 12, 10:15 UTC23h 55m
2026-07-11 AIA490F - Jul 11, 07:20 UTCJul 11, 11:40 UTC4h 20m
2026-07-10 FHDSJ - Jul 10, 14:00 UTCJul 10, 14:35 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-HDSJ page for operator, model, and routing details .

Mode-S 398E49 frequently asked

What is Mode-S code 398E49?
398E49 is an ICAO 24-bit transponder address. Allocated to France. Assigned to F-HDSJ.
Where is Mode-S 398E49 registered?
Mode-S code 398E49 is allocated to France (FR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 398E49 broadcasting right now?
No active broadcast right now. Last signal was 3h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 398E49, octal 16307111, decimal 3,771,977.
What flights does 398E49 operate?
Mode-S 398E49 has broadcast 4 distinct callsigns, including AIA491, FHDSJ, AIA491F, AIA490F.