sensors Mode-S transponder

39CFDC

ICAO 24-bit transponder address · allocated to France

Currently assigned to F-JUCW · AEROSPOOL WT-9 Dynamic

Hex
39CFDC
Octal
16347734
Decimal
3,788,764
Country
FR
Tail
F-JUCW
Type
WT9
No current signal · last broadcast 23h ago
Flights observed
1
Distinct callsigns
1
Country
FR
Last broadcast
23h ago

Last known position

Most recent position reported by Mode-S 39CFDC.

Country allocation

The ICAO 24-bit address 39CFDC 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
FJUCW - 1 2026-04-14

Recent flights last 1

DateFlightRouteTakeoffLandingDuration
2026-04-14 FJUCW - Apr 14, 09:45 UTCApr 14, 10:00 UTC15m

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

Mode-S 39CFDC frequently asked

What is Mode-S code 39CFDC?
39CFDC is an ICAO 24-bit transponder address. Allocated to France. Assigned to F-JUCW.
Where is Mode-S 39CFDC registered?
Mode-S code 39CFDC is allocated to France (FR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 39CFDC broadcasting right now?
No active broadcast right now. Last signal was 23h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 39CFDC, octal 16347734, decimal 3,788,764.
What flights does 39CFDC operate?
Mode-S 39CFDC has broadcast 1 distinct callsign, including FJUCW.