sensors Mode-S transponder

4B1939

ICAO 24-bit transponder address · allocated to Switzerland

Currently assigned to HB-JOJ · AIRBUS A-319

Hex
4B1939
Octal
22614471
Decimal
4,921,657
Country
CH
Tail
HB-JOJ
Type
A319
Broadcasting now · callsign CSW606 · 35,050 ft
Flights observed
325
Distinct callsigns
20
Country
CH
Last broadcast
Jul 26, 19:15 UTC

Current position

4B1939 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 4B1939 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 20 distinct

Callsign Airline Flights Last seen
CSW8GJ - 54 2026-07-25
CSW8HE - 53 2026-07-25
CSW802 - 21 2026-07-24
CSW805 Worldwide Air Charter Systems 20 2026-07-26
CSW803 Worldwide Air Charter Systems 20 2026-07-24
CSW804 Worldwide Air Charter Systems 19 2026-07-26
CSW630 - 14 2026-07-26
CSW631 - 13 2026-07-26
CSW638 - 11 2026-06-25
CSW890 - 9 2026-05-02
CSW639 Worldwide Air Charter Systems 9 2026-06-25
CSW606 Worldwide Air Charter Systems 7 2026-07-25
CSW604 Worldwide Air Charter Systems 7 2026-07-22
CSW891 - 6 2026-05-02
CSW607 Worldwide Air Charter Systems 6 2026-07-18
CSW1PM - 6 2026-07-02
CSW177 - 6 2026-07-22
CSW605 Worldwide Air Charter Systems 5 2026-07-22
CSW1EP - 5 2026-07-02
CSW176 - 5 2026-07-20

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 CSW631 - Jul 26, 17:50 UTCJul 26, 19:10 UTC1h 20m
2026-07-26 CSW630 - Jul 26, 14:40 UTCJul 26, 16:05 UTC1h 25m
2026-07-26 CSW805 KGS → ZRH Jul 26, 10:10 UTCJul 26, 13:10 UTC3h 0m
2026-07-26 CSW804 ZRH → KGS Jul 26, 05:45 UTCJul 26, 08:20 UTC2h 36m
2026-07-25 CSW8HE - Jul 25, 18:05 UTCJul 25, 20:55 UTC2h 50m
2026-07-25 CSW8GJ - Jul 25, 14:10 UTCJul 25, 16:25 UTC2h 15m
2026-07-25 CSW606 ZRH → PRN Jul 25, 06:00 UTCJul 25, 12:35 UTC6h 35m
2026-07-24 CSW803 RHO → ZRH Jul 24, 17:55 UTCJul 24, 20:55 UTC3h 0m
2026-07-24 CSW802 - Jul 24, 14:05 UTCJul 24, 16:35 UTC2h 30m
2026-07-24 CSW8HE - Jul 24, 10:00 UTCJul 24, 12:45 UTC2h 45m
2026-07-24 CSW8GJ - Jul 24, 06:00 UTCJul 24, 08:15 UTC2h 15m
2026-07-23 CSW745 - Jul 23, 17:40 UTCJul 23, 19:10 UTC1h 30m
2026-07-23 CSW744 - Jul 23, 15:05 UTCJul 23, 16:15 UTC1h 10m
2026-07-23 CSW805 - Jul 23, 09:40 UTCJul 23, 12:35 UTC2h 55m
2026-07-23 CSW804 ZRH → KGS Jul 23, 05:25 UTCJul 23, 07:40 UTC2h 15m
2026-07-22 CSW605 PRN → ZRH Jul 22, 17:00 UTCJul 22, 18:45 UTC1h 45m
2026-07-22 CSW604 ZRH → PRN Jul 22, 14:15 UTCJul 22, 15:35 UTC1h 20m
2026-07-22 CSW177 - Jul 22, 10:20 UTCJul 22, 13:00 UTC2h 40m
2026-07-21 CSW797 - Jul 21, 17:25 UTCJul 21, 19:20 UTC1h 55m
2026-07-21 CSW796 ZRH → TIA Jul 21, 14:30 UTCJul 21, 15:55 UTC1h 25m
2026-07-21 CSW805 - Jul 21, 08:40 UTCJul 21, 11:30 UTC2h 50m
2026-07-21 CSW804 ZRH → KGS Jul 21, 04:45 UTCJul 21, 07:10 UTC2h 25m
2026-07-20 CSW177 - Jul 20, 23:20 UTCJul 20, 23:55 UTC34m
2026-07-20 CSW177 OPO → ZRH Jul 20, 18:50 UTCJul 20, 21:15 UTC2h 25m
2026-07-20 CSW176 - Jul 20, 15:25 UTCJul 20, 17:50 UTC2h 25m
2026-07-20 CSW803 RHO → ZRH Jul 20, 11:30 UTCJul 20, 14:25 UTC2h 55m
2026-07-20 CSW802 - Jul 20, 07:40 UTCJul 20, 10:10 UTC2h 30m
2026-07-20 CSW1631 SKP → ZRH Jul 20, 03:45 UTCJul 20, 05:30 UTC1h 45m
2026-07-19 CSW630 - Jul 19, 18:30 UTCJul 19, 19:00 UTC30m
2026-07-19 CSW630 - Jul 19, 16:00 UTCJul 19, 17:20 UTC1h 20m
2026-07-18 CSW8HE - Jul 18, 18:35 UTCJul 18, 21:15 UTC2h 40m
2026-07-18 CSW8GJ - Jul 18, 14:55 UTCJul 18, 17:10 UTC2h 15m
2026-07-18 CSW607 PRN → ZRH Jul 18, 10:55 UTCJul 18, 12:30 UTC1h 35m
2026-07-18 CSW606 - Jul 18, 06:05 UTCJul 18, 07:20 UTC1h 15m
2026-07-17 CSW5605 - Jul 17, 18:19 UTCJul 17, 20:15 UTC1h 55m
2026-07-17 CSW604 ZRH → PRN Jul 17, 15:49 UTCJul 17, 17:09 UTC1h 20m
2026-07-17 CSW445 ZRH → ZRH Jul 17, 05:15 UTCJul 17, 14:39 UTC9h 25m
2026-07-17 CSW5633 - Jul 17, 02:05 UTCJul 17, 04:04 UTC2h 0m
2026-07-16 CSW632 - Jul 16, 21:00 UTCJul 16, 22:25 UTC1h 25m
2026-07-16 CSW745 - Jul 16, 18:25 UTCJul 16, 19:55 UTC1h 30m
2026-07-16 CSW744 - Jul 16, 14:55 UTCJul 16, 16:05 UTC1h 10m
2026-07-16 CSW797 - Jul 16, 12:05 UTCJul 16, 13:49 UTC1h 45m
2026-07-16 CSW796 - Jul 16, 09:10 UTCJul 16, 10:29 UTC1h 20m
2026-07-15 CSW605 PRN → ZRH Jul 15, 17:30 UTCJul 15, 19:10 UTC1h 40m
2026-07-15 CSW604 ZRH → PRN Jul 15, 14:55 UTCJul 15, 16:15 UTC1h 20m
2026-07-15 CSW177 OPO → ZRH Jul 15, 10:30 UTCJul 15, 12:30 UTC2h 0m
2026-07-15 CSW176 ZRH → OPO Jul 15, 07:00 UTCJul 15, 09:25 UTC2h 25m
2026-07-14 CSW797 - Jul 14, 17:15 UTCJul 14, 18:55 UTC1h 40m
2026-07-14 CSW796 - Jul 14, 14:10 UTCJul 14, 15:25 UTC1h 15m
2026-07-14 CSW805 - Jul 14, 08:55 UTCJul 14, 11:50 UTC2h 55m

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

Mode-S 4B1939 frequently asked

What is Mode-S code 4B1939?
4B1939 is an ICAO 24-bit transponder address. Allocated to Switzerland. Assigned to HB-JOJ.
Where is Mode-S 4B1939 registered?
Mode-S code 4B1939 is allocated to Switzerland (CH). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4B1939 broadcasting right now?
Yes. Mode-S 4B1939 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4B1939, octal 22614471, decimal 4,921,657.
What flights does 4B1939 operate?
Mode-S 4B1939 has broadcast 20 distinct callsigns, including CSW8GJ, CSW8HE, CSW802, CSW805, CSW803.