Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

4B3021

ICAO 24-bit transponder address · allocated to Switzerland

Currently assigned to HB-SFX · AQUILA A-210

Hex
4B3021
Octal
22630041
Decimal
4,927,521
Country
CH
Tail
HB-SFX
Type
A210
No current signal · last broadcast 19h ago
Flights observed
103
Distinct callsigns
1
Country
CH
Last broadcast
19h ago

Last known position

Most recent position reported by Mode-S 4B3021.

Country allocation

The ICAO 24-bit address 4B3021 falls within the block assigned to Switzerland (CH) by ICAO Annex 10, Volume III. Every aircraft registered in Switzerland 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
HBSFX - 103 2026-07-17

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-17 HBSFX - Jul 17, 06:10 UTCJul 17, 07:14 UTC1h 5m
2026-07-16 HBSFX - Jul 16, 06:15 UTCJul 16, 07:00 UTC45m
2026-07-11 HBSFX - Jul 11, 12:10 UTCJul 11, 12:50 UTC40m
2026-07-10 HBSFX - Jul 10, 10:40 UTCJul 10, 11:30 UTC50m
2026-07-10 HBSFX - Jul 10, 09:10 UTCJul 10, 09:25 UTC15m
2026-07-10 HBSFX - Jul 10, 07:45 UTCJul 10, 08:25 UTC40m
2026-07-08 HBSFX - Jul 8, 11:25 UTCJul 8, 11:55 UTC30m
2026-07-08 HBSFX - Jul 8, 08:50 UTCJul 8, 09:55 UTC1h 5m
2026-07-08 HBSFX - Jul 8, 07:20 UTCJul 8, 07:55 UTC35m
2026-07-07 HBSFX - Jul 7, 17:15 UTCJul 7, 18:20 UTC1h 5m
2026-07-07 HBSFX - Jul 7, 13:40 UTCJul 7, 15:00 UTC1h 20m
2026-07-07 HBSFX - Jul 7, 11:15 UTCJul 7, 11:45 UTC30m
2026-07-07 HBSFX - Jul 7, 06:10 UTCJul 7, 07:10 UTC1h 0m
2026-07-06 HBSFX - Jul 6, 08:35 UTCJul 6, 09:45 UTC1h 10m
2026-07-06 HBSFX - Jul 6, 07:00 UTCJul 6, 07:55 UTC55m
2026-07-04 HBSFX - Jul 4, 14:10 UTCJul 4, 14:35 UTC25m
2026-07-04 HBSFX - Jul 4, 12:30 UTCJul 4, 13:05 UTC35m
2026-07-04 HBSFX - Jul 4, 06:15 UTCJul 4, 06:35 UTC20m
2026-07-03 HBSFX - Jul 3, 14:55 UTCJul 3, 15:45 UTC50m
2026-07-03 HBSFX - Jul 3, 12:30 UTCJul 3, 13:20 UTC50m
2026-07-03 HBSFX - Jul 3, 08:55 UTCJul 3, 09:45 UTC50m
2026-07-03 HBSFX - Jul 3, 08:05 UTCJul 3, 08:20 UTC15m
2026-07-03 HBSFX - Jul 3, 06:35 UTCJul 3, 07:30 UTC55m
2026-07-02 HBSFX - Jul 2, 14:30 UTCJul 2, 15:05 UTC35m
2026-07-02 HBSFX - Jul 2, 12:30 UTCJul 2, 13:40 UTC1h 10m
2026-06-30 HBSFX - Jun 30, 06:35 UTCJun 30, 07:55 UTC1h 20m
2026-06-29 HBSFX - Jun 29, 15:14 UTCJun 29, 15:49 UTC35m
2026-06-28 HBSFX - Jun 28, 09:30 UTCJun 28, 10:44 UTC1h 15m
2026-06-27 HBSFX - Jun 27, 12:15 UTCJun 27, 13:15 UTC1h 0m
2026-06-27 HBSFX - Jun 27, 10:25 UTCJun 27, 11:20 UTC55m
2026-06-27 HBSFX - Jun 27, 08:39 UTCJun 27, 09:40 UTC1h 0m
2026-06-27 HBSFX - Jun 27, 06:50 UTCJun 27, 07:55 UTC1h 5m
2026-06-26 HBSFX - Jun 26, 07:30 UTCJun 26, 07:50 UTC20m
2026-06-26 HBSFX - Jun 26, 06:25 UTCJun 26, 06:45 UTC20m
2026-06-25 HBSFX - Jun 25, 08:04 UTCJun 25, 08:55 UTC50m
2026-06-25 HBSFX - Jun 25, 05:29 UTCJun 25, 06:09 UTC40m
2026-06-24 HBSFX - Jun 24, 12:34 UTCJun 24, 13:05 UTC30m
2026-06-24 HBSFX - Jun 24, 10:45 UTCJun 24, 11:29 UTC45m
2026-06-24 HBSFX - Jun 24, 08:20 UTCJun 24, 10:04 UTC1h 45m
2026-06-24 HBSFX - Jun 24, 06:59 UTCJun 24, 07:34 UTC35m
2026-06-23 HBSFX - Jun 23, 13:24 UTCJun 23, 14:15 UTC50m
2026-06-23 HBSFX - Jun 23, 12:15 UTCJun 23, 12:49 UTC35m
2026-06-23 HBSFX - Jun 23, 10:44 UTCJun 23, 11:24 UTC40m
2026-06-23 HBSFX - Jun 23, 09:20 UTCJun 23, 10:04 UTC45m
2026-06-23 HBSFX - Jun 23, 07:05 UTCJun 23, 08:45 UTC1h 40m
2026-06-20 HBSFX - Jun 20, 13:44 UTCJun 20, 14:14 UTC30m
2026-06-20 HBSFX - Jun 20, 12:24 UTCJun 20, 12:50 UTC25m
2026-06-20 HBSFX - Jun 20, 08:59 UTCJun 20, 09:59 UTC1h 0m
2026-06-18 HBSFX - Jun 18, 08:15 UTCJun 18, 09:00 UTC45m
2026-06-18 HBSFX - Jun 18, 06:50 UTCJun 18, 07:25 UTC35m

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 HB-SFX page for operator, model, and routing details .

Mode-S 4B3021 frequently asked

What is Mode-S code 4B3021?
4B3021 is an ICAO 24-bit transponder address. Allocated to Switzerland. Assigned to HB-SFX.
Where is Mode-S 4B3021 registered?
Mode-S code 4B3021 is allocated to Switzerland (CH). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4B3021 broadcasting right now?
No active broadcast right now. Last signal was 19h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4B3021, octal 22630041, decimal 4,927,521.
What flights does 4B3021 operate?
Mode-S 4B3021 has broadcast 1 distinct callsign, including HBSFX.