sensors Mode-S transponder

3942DC

ICAO 24-bit transponder address · allocated to France

Currently assigned to F-JYAC · BRM AERO NG-5/6 Bristell

Hex
3942DC
Octal
16241334
Decimal
3,752,668
Country
FR
Tail
F-JYAC
Type
NG5
No current signal · last broadcast Jul 9, 11:55 UTC
Flights observed
3
Distinct callsigns
1
Country
FR
Last broadcast
Jul 9, 11:55 UTC

Last known position

Most recent position reported by Mode-S 3942DC.

Country allocation

The ICAO 24-bit address 3942DC 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
FJYAC - 3 2026-07-09

Recent flights last 3

DateFlightRouteTakeoffLandingDuration
2026-07-09 FJYAC - Jul 9, 09:55 UTCJul 9, 11:55 UTC2h 0m
2026-04-26 FJYAC - Apr 26, 17:05 UTCApr 26, 17:45 UTC40m
2026-04-22 FJYAC - Apr 22, 13:20 UTCApr 22, 14:35 UTC1h 15m

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

Mode-S 3942DC frequently asked

What is Mode-S code 3942DC?
3942DC is an ICAO 24-bit transponder address. Allocated to France. Assigned to F-JYAC.
Where is Mode-S 3942DC registered?
Mode-S code 3942DC is allocated to France (FR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 3942DC broadcasting right now?
No active broadcast right now. Last signal was Jul 9, 11:55 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 3942DC, octal 16241334, decimal 3,752,668.
What flights does 3942DC operate?
Mode-S 3942DC has broadcast 1 distinct callsign, including FJYAC.