sensors Mode-S transponder

39ACA4

ICAO 24-bit transponder address · allocated to France

Currently assigned to F-HLFE · CESSNA 525B Citation CJ3

Hex
39ACA4
Octal
16326244
Decimal
3,779,748
Country
FR
Tail
F-HLFE
Type
C25B
No current signal · last broadcast 12d ago
Flights observed
37
Distinct callsigns
1
Country
FR
Last broadcast
12d ago

Last known position

Most recent position reported by Mode-S 39ACA4.

Country allocation

The ICAO 24-bit address 39ACA4 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
FHLFE - 37 2026-05-18

Recent flights last 37

DateFlightRouteTakeoffLandingDuration
2026-05-18 FHLFE - May 18, 06:20 UTCMay 18, 07:00 UTC40m
2026-05-17 FHLFE - May 17, 17:20 UTCMay 17, 17:30 UTC10m
2026-05-17 FHLFE - May 17, 14:55 UTCMay 17, 16:25 UTC1h 30m
2026-05-17 FHLFE - May 17, 08:55 UTCMay 17, 10:25 UTC1h 30m
2026-05-13 FHLFE - May 13, 16:00 UTCMay 13, 17:45 UTC1h 45m
2026-05-13 FHLFE - May 13, 13:31 UTCMay 13, 15:05 UTC1h 35m
2026-05-13 FHLFE - May 13, 11:15 UTCMay 13, 12:35 UTC1h 20m
2026-05-13 FHLFE - May 13, 10:35 UTCMay 13, 10:45 UTC10m
2026-05-11 FHLFE - May 11, 09:25 UTCMay 11, 11:10 UTC1h 45m
2026-05-11 FHLFE - May 11, 06:10 UTCMay 11, 07:55 UTC1h 45m
2026-05-06 FHLFE - May 6, 14:25 UTCMay 6, 14:35 UTC10m
2026-05-06 FHLFE BOD → LME May 6, 12:35 UTCMay 6, 13:25 UTC50m
2026-05-06 FHLFE - May 6, 05:40 UTCMay 6, 06:20 UTC40m
2026-05-05 FHLFE - May 5, 12:25 UTCMay 5, 15:15 UTC2h 50m
2026-05-04 FHLFE - May 4, 09:40 UTCMay 4, 09:55 UTC15m
2026-05-04 FHLFE - May 4, 06:05 UTCMay 4, 08:40 UTC2h 35m
2026-05-03 FHLFE - May 3, 15:05 UTCMay 3, 15:20 UTC15m
2026-05-01 FHLFE - May 1, 08:05 UTCMay 1, 09:55 UTC1h 50m
2026-04-30 FHLFE - Apr 30, 18:45 UTCApr 30, 20:25 UTC1h 40m
2026-04-29 FHLFE - Apr 29, 10:20 UTCApr 29, 12:10 UTC1h 50m
2026-04-29 FHLFE - Apr 29, 04:29 UTCApr 29, 06:10 UTC1h 40m
2026-04-26 FHLFE - Apr 26, 09:10 UTCApr 26, 10:45 UTC1h 35m
2026-04-23 FHLFE - Apr 23, 08:05 UTCApr 23, 09:35 UTC1h 30m
2026-04-22 FHLFE - Apr 22, 18:05 UTCApr 22, 18:30 UTC25m
2026-04-22 FHLFE - Apr 22, 17:05 UTCApr 22, 17:35 UTC30m
2026-04-22 FHLFE - Apr 22, 13:40 UTCApr 22, 16:20 UTC2h 40m
2026-04-20 FHLFE - Apr 20, 10:35 UTCApr 20, 12:55 UTC2h 20m
2026-04-17 FHLFE - Apr 17, 17:25 UTCApr 17, 18:10 UTC45m
2026-04-17 FHLFE - Apr 17, 15:40 UTCApr 17, 17:15 UTC1h 35m
2026-04-17 FHLFE - Apr 17, 05:20 UTCApr 17, 06:45 UTC1h 25m
2026-04-16 FHLFE - Apr 16, 14:50 UTCApr 16, 15:10 UTC20m
2026-04-16 FHLFE - Apr 16, 13:44 UTCApr 16, 14:05 UTC20m
2026-04-16 FHLFE - Apr 16, 06:40 UTCApr 16, 07:00 UTC20m
2026-04-14 FHLFE - Apr 14, 14:50 UTCApr 14, 16:05 UTC1h 15m
2026-04-14 FHLFE - Apr 14, 14:30 UTCApr 14, 14:45 UTC15m
2026-04-13 FHLFE - Apr 13, 11:55 UTCApr 13, 12:10 UTC15m
2026-04-13 FHLFE - Apr 13, 10:45 UTCApr 13, 12:10 UTC1h 25m

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

Mode-S 39ACA4 frequently asked

What is Mode-S code 39ACA4?
39ACA4 is an ICAO 24-bit transponder address. Allocated to France. Assigned to F-HLFE.
Where is Mode-S 39ACA4 registered?
Mode-S code 39ACA4 is allocated to France (FR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 39ACA4 broadcasting right now?
No active broadcast right now. Last signal was 12d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 39ACA4, octal 16326244, decimal 3,779,748.
What flights does 39ACA4 operate?
Mode-S 39ACA4 has broadcast 1 distinct callsign, including FHLFE.