sensors Mode-S transponder

3991E0

ICAO 24-bit transponder address · allocated to France

Currently assigned to F-HEPA · AIRBUS A-320

Hex
3991E0
Octal
16310740
Decimal
3,772,896
Country
FR
Tail
F-HEPA
Type
A320
Photo of F-HEPA
No current signal · last broadcast 12h ago
Flights observed
13
Distinct callsigns
11
Country
FR
Last broadcast
12h ago

Last known position

Most recent position reported by Mode-S 3991E0.

Country allocation

The ICAO 24-bit address 3991E0 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 11 distinct

Callsign Airline Flights Last seen
AFR97UB - 2 2026-04-13
AFR12HA - 2 2026-04-14
AFR96WQ - 1 2026-04-13
AFR79RD Air France 1 2026-04-13
AFR78DU Air France 1 2026-04-14
AFR53MJ - 1 2026-04-12
AFR38PA - 1 2026-04-13
AFR33NA - 1 2026-04-13
AFR24MF - 1 2026-04-12
AFR24JD - 1 2026-04-13
AFR1241 - 1 2026-04-13

Recent flights last 13

DateFlightRouteTakeoffLandingDuration
2026-04-14 AFR12HA - Apr 14, 09:10 UTCApr 14, 10:55 UTC1h 45m
2026-04-14 AFR12HA - Apr 14, 08:05 UTCApr 14, 09:05 UTC1h 0m
2026-04-14 AFR78DU FCO → CDG Apr 14, 05:15 UTCApr 14, 06:35 UTC1h 20m
2026-04-13 AFR97UB - Apr 13, 19:50 UTCApr 13, 21:00 UTC1h 10m
2026-04-13 AFR97UB - Apr 13, 19:30 UTCApr 13, 20:10 UTC40m
2026-04-13 AFR38PA - Apr 13, 16:55 UTCApr 13, 17:40 UTC45m
2026-04-13 AFR96WQ - Apr 13, 14:55 UTCApr 13, 15:35 UTC40m
2026-04-13 AFR33NA - Apr 13, 12:30 UTCApr 13, 13:30 UTC1h 0m
2026-04-13 AFR24JD - Apr 13, 10:40 UTCApr 13, 11:30 UTC50m
2026-04-13 AFR1241 - Apr 13, 08:25 UTCApr 13, 09:10 UTC45m
2026-04-13 AFR79RD CDG → AMS Apr 13, 05:35 UTCApr 13, 06:20 UTC45m
2026-04-12 AFR53MJ - Apr 12, 19:00 UTCApr 12, 20:15 UTC1h 15m
2026-04-12 AFR24MF - Apr 12, 17:15 UTCApr 12, 17:30 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-HEPA page for operator, model, and routing details .

Mode-S 3991E0 frequently asked

What is Mode-S code 3991E0?
3991E0 is an ICAO 24-bit transponder address. Allocated to France. Assigned to F-HEPA.
Where is Mode-S 3991E0 registered?
Mode-S code 3991E0 is allocated to France (FR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 3991E0 broadcasting right now?
No active broadcast right now. Last signal was 12h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 3991E0, octal 16310740, decimal 3,772,896.
What flights does 3991E0 operate?
Mode-S 3991E0 has broadcast 11 distinct callsigns, including AFR97UB, AFR12HA, AFR96WQ, AFR79RD, AFR78DU.