Apparatus

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sensors Mode-S transponder

4B1B9D

ICAO 24-bit transponder address · allocated to Switzerland

Currently assigned to HB-KLX · ROBIN DR-400

Hex
4B1B9D
Octal
22615635
Decimal
4,922,269
Country
CH
Tail
HB-KLX
Type
DR40
No current signal · last broadcast 20h ago
Flights observed
176
Distinct callsigns
1
Country
CH
Last broadcast
20h ago

Last known position

Most recent position reported by Mode-S 4B1B9D.

Country allocation

The ICAO 24-bit address 4B1B9D 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
HBKLX - 176 2026-07-17

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-17 HBKLX - Jul 17, 09:40 UTCJul 17, 10:10 UTC30m
2026-07-16 HBKLX - Jul 16, 10:35 UTCJul 16, 10:59 UTC25m
2026-07-16 HBKLX - Jul 16, 07:35 UTCJul 16, 08:35 UTC1h 0m
2026-07-15 HBKLX - Jul 15, 15:55 UTCJul 15, 17:05 UTC1h 10m
2026-07-14 HBKLX - Jul 14, 16:35 UTCJul 14, 16:50 UTC15m
2026-07-14 HBKLX - Jul 14, 15:55 UTCJul 14, 16:05 UTC10m
2026-07-14 HBKLX - Jul 14, 08:30 UTCJul 14, 10:05 UTC1h 35m
2026-07-13 HBKLX - Jul 13, 15:55 UTCJul 13, 16:40 UTC45m
2026-07-13 HBKLX - Jul 13, 09:30 UTCJul 13, 10:00 UTC30m
2026-07-12 HBKLX - Jul 12, 19:20 UTCJul 12, 19:50 UTC30m
2026-07-11 HBKLX - Jul 11, 09:50 UTCJul 11, 10:20 UTC30m
2026-07-11 HBKLX - Jul 11, 07:30 UTCJul 11, 08:30 UTC1h 0m
2026-07-10 HBKLX - Jul 10, 14:10 UTCJul 10, 14:55 UTC45m
2026-07-10 HBKLX - Jul 10, 06:05 UTCJul 10, 07:30 UTC1h 25m
2026-07-09 HBKLX - Jul 9, 18:35 UTCJul 9, 19:00 UTC25m
2026-07-09 HBKLX - Jul 9, 16:40 UTCJul 9, 17:20 UTC40m
2026-07-09 HBKLX - Jul 9, 12:30 UTCJul 9, 14:00 UTC1h 30m
2026-07-09 HBKLX - Jul 9, 09:10 UTCJul 9, 09:25 UTC15m
2026-07-09 HBKLX - Jul 9, 07:35 UTCJul 9, 08:20 UTC45m
2026-07-08 HBKLX - Jul 8, 16:10 UTCJul 8, 16:50 UTC40m
2026-07-08 HBKLX - Jul 8, 09:30 UTCJul 8, 09:45 UTC15m
2026-07-07 HBKLX - Jul 7, 17:50 UTCJul 7, 18:20 UTC30m
2026-07-03 HBKLX - Jul 3, 12:35 UTCJul 3, 12:55 UTC20m
2026-07-02 HBKLX - Jul 2, 14:00 UTCJul 2, 14:15 UTC15m
2026-07-02 HBKLX - Jul 2, 13:20 UTCJul 2, 13:40 UTC20m
2026-07-02 HBKLX - Jul 2, 12:40 UTCJul 2, 13:00 UTC20m
2026-07-01 HBKLX - Jul 1, 15:30 UTCJul 1, 16:40 UTC1h 10m
2026-06-30 HBKLX - Jun 30, 17:30 UTCJun 30, 17:55 UTC25m
2026-06-29 HBKLX - Jun 29, 16:44 UTCJun 29, 16:50 UTC5m
2026-06-27 HBKLX - Jun 27, 08:29 UTCJun 27, 09:15 UTC45m
2026-06-26 HBKLX - Jun 26, 19:20 UTCJun 26, 19:35 UTC15m
2026-06-26 HBKLX - Jun 26, 09:35 UTCJun 26, 10:20 UTC45m
2026-06-23 HBKLX - Jun 23, 05:45 UTCJun 23, 07:25 UTC1h 40m
2026-06-22 HBKLX - Jun 22, 15:05 UTCJun 22, 15:35 UTC30m
2026-06-22 HBKLX - Jun 22, 09:10 UTCJun 22, 09:54 UTC45m
2026-06-22 HBKLX - Jun 22, 08:04 UTCJun 22, 08:29 UTC25m
2026-06-21 HBKLX - Jun 21, 15:15 UTCJun 21, 15:49 UTC35m
2026-06-21 HBKLX - Jun 21, 14:10 UTCJun 21, 14:40 UTC30m
2026-06-21 HBKLX - Jun 21, 12:35 UTCJun 21, 13:09 UTC35m
2026-06-21 HBKLX - Jun 21, 10:25 UTCJun 21, 11:49 UTC1h 25m
2026-06-19 HBKLX - Jun 19, 08:29 UTCJun 19, 09:59 UTC1h 30m
2026-06-19 HBKLX - Jun 19, 06:54 UTCJun 19, 07:39 UTC45m
2026-06-18 HBKLX - Jun 18, 14:35 UTCJun 18, 15:45 UTC1h 10m
2026-06-13 HBKLX - Jun 13, 09:30 UTCJun 13, 10:20 UTC50m
2026-06-13 HBKLX - Jun 13, 07:40 UTCJun 13, 08:40 UTC1h 0m
2026-06-12 HBKLX - Jun 12, 16:00 UTCJun 12, 16:35 UTC35m
2026-06-12 HBKLX - Jun 12, 14:10 UTCJun 12, 14:45 UTC35m
2026-06-12 HBKLX - Jun 12, 13:15 UTCJun 12, 13:35 UTC20m
2026-06-11 HBKLX - Jun 11, 16:15 UTCJun 11, 16:20 UTC5m
2026-06-11 HBKLX - Jun 11, 15:35 UTCJun 11, 16:10 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-KLX page for operator, model, and routing details .

Mode-S 4B1B9D frequently asked

What is Mode-S code 4B1B9D?
4B1B9D is an ICAO 24-bit transponder address. Allocated to Switzerland. Assigned to HB-KLX.
Where is Mode-S 4B1B9D registered?
Mode-S code 4B1B9D is allocated to Switzerland (CH). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4B1B9D broadcasting right now?
No active broadcast right now. Last signal was 20h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4B1B9D, octal 22615635, decimal 4,922,269.
What flights does 4B1B9D operate?
Mode-S 4B1B9D has broadcast 1 distinct callsign, including HBKLX.