sensors Mode-S transponder

3949E8

ICAO 24-bit transponder address · allocated to France

Currently assigned to F-GSPI · BOEING 777-200

Hex
3949E8
Octal
16244750
Decimal
3,754,472
Country
FR
Tail
F-GSPI
Type
B772
Photo of F-GSPI
No current signal · last broadcast 1d ago
Flights observed
5
Distinct callsigns
3
Country
FR
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 3949E8.

Country allocation

The ICAO 24-bit address 3949E8 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 3 distinct

Callsign Airline Flights Last seen
AFR187 Air France 3 2026-04-13
AFR930 - 1 2026-04-13
AFR186 Air France 1 2026-04-12

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-13 AFR930 - Apr 13, 20:40 UTCApr 13, 22:55 UTC2h 15m
2026-04-13 AFR187 CDG → LAS Apr 13, 12:50 UTCApr 13, 14:40 UTC1h 50m
2026-04-13 AFR187 CDG → LAS Apr 13, 05:20 UTCApr 13, 06:15 UTC55m
2026-04-13 AFR187 CDG → LAS Apr 13, 00:20 UTCApr 13, 00:55 UTC35m
2026-04-12 AFR186 LAS → CDG Apr 12, 19:00 UTCApr 12, 20:15 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-GSPI page for operator, model, and routing details .

Mode-S 3949E8 frequently asked

What is Mode-S code 3949E8?
3949E8 is an ICAO 24-bit transponder address. Allocated to France. Assigned to F-GSPI.
Where is Mode-S 3949E8 registered?
Mode-S code 3949E8 is allocated to France (FR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 3949E8 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 3949E8, octal 16244750, decimal 3,754,472.
What flights does 3949E8 operate?
Mode-S 3949E8 has broadcast 3 distinct callsigns, including AFR187, AFR930, AFR186.