sensors Mode-S transponder

39ACE2

ICAO 24-bit transponder address · allocated to France

Currently assigned to F-HLHC · TECNAM Twenty-Ten

Hex
39ACE2
Octal
16326342
Decimal
3,779,810
Country
FR
Tail
F-HLHC
Type
TWEN
No current signal · last broadcast 14h ago
Flights observed
6
Distinct callsigns
1
Country
FR
Last broadcast
14h ago

Last known position

Most recent position reported by Mode-S 39ACE2.

Country allocation

The ICAO 24-bit address 39ACE2 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
FHLHC - 6 2026-04-14

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-14 FHLHC - Apr 14, 07:25 UTCApr 14, 08:45 UTC1h 20m
2026-04-13 FHLHC - Apr 13, 15:50 UTCApr 13, 16:10 UTC20m
2026-04-13 FHLHC - Apr 13, 15:40 UTCApr 13, 16:10 UTC30m
2026-04-13 FHLHC - Apr 13, 14:25 UTCApr 13, 14:50 UTC25m
2026-04-13 FHLHC - Apr 13, 12:40 UTCApr 13, 13:10 UTC30m
2026-04-13 FHLHC LAI → TNF Apr 13, 09:20 UTCApr 13, 11:45 UTC2h 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-HLHC page for operator, model, and routing details .

Mode-S 39ACE2 frequently asked

What is Mode-S code 39ACE2?
39ACE2 is an ICAO 24-bit transponder address. Allocated to France. Assigned to F-HLHC.
Where is Mode-S 39ACE2 registered?
Mode-S code 39ACE2 is allocated to France (FR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 39ACE2 broadcasting right now?
No active broadcast right now. Last signal was 14h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 39ACE2, octal 16326342, decimal 3,779,810.
What flights does 39ACE2 operate?
Mode-S 39ACE2 has broadcast 1 distinct callsign, including FHLHC.