Apparatus

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sensors Mode-S transponder

7821B4

ICAO 24-bit transponder address · allocated to China

Currently assigned to B-32JZ · AIRBUS A-321neo

Hex
7821B4
Octal
36020664
Decimal
7,872,948
Country
CN
Tail
B-32JZ
Type
A21N
No current signal · last broadcast 4h ago
Flights observed
57
Distinct callsigns
20
Country
CN
Last broadcast
4h ago

Last known position

Most recent position reported by Mode-S 7821B4.

Country allocation

The ICAO 24-bit address 7821B4 falls within the block assigned to China (CN) by ICAO Annex 10, Volume III. Every aircraft registered in China 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
CSN6670 China Southern Airlines 12 2026-05-26
CSN6758 China Southern Airlines 6 2026-05-22
CSN6757 China Southern Airlines 4 2026-04-26
CSN6630 China Southern Airlines 4 2026-05-23
CSN6754 China Southern Airlines 3 2026-05-20
CSN6624 China Southern Airlines 3 2026-05-30
CSN6148 China Southern Airlines 3 2026-05-18
CSN6762 China Southern Airlines 2 2026-05-04
CSN6736 China Southern Airlines 2 2026-05-06
CSN6623 China Southern Airlines 2 2026-05-29
CSN3369 China Southern Airlines 2 2026-04-25
CSN6782 China Southern Airlines 1 2026-05-02
CSN6781 China Southern Airlines 1 2026-05-30
CSN6735 China Southern Airlines 1 2026-05-20
CSN6732 China Southern Airlines 1 2026-05-22
CSN6669 China Southern Airlines 1 2026-05-20
CSN6323 - 1 2026-05-04
CSN6227 China Southern Airlines 1 2026-05-28
CSN6147 China Southern Airlines 1 2026-04-29
CSN5671 China Southern Airlines 1 2026-05-04

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 CSN6781 SYX → PVG May 30, 08:35 UTCMay 30, 10:45 UTC2h 10m
2026-05-30 CSN6624 NKG → SYX May 30, 05:45 UTCMay 30, 06:00 UTC15m
2026-05-29 CSN6623 SYX → NKG May 29, 09:10 UTCMay 30, 06:00 UTC20h 50m
2026-05-29 CSN6623 SYX → NKG May 29, 00:00 UTCMay 29, 09:35 UTC9h 35m
2026-05-28 CSN6227 SYX → CKG May 28, 00:05 UTCMay 28, 12:50 UTC12h 45m
2026-05-26 CSN6670 CGQ → SYX May 26, 04:10 UTCMay 26, 16:05 UTC11h 55m
2026-05-25 CSN6670 CGQ → SYX May 25, 15:45 UTCMay 26, 08:39 UTC16h 54m
2026-05-25 CSN6624 NKG → SYX May 25, 05:35 UTCMay 25, 05:50 UTC15m
2026-05-24 CSN6624 NKG → SYX May 24, 09:20 UTCMay 25, 05:50 UTC20h 30m
2026-05-23 CSN6630 CGQ → HGH May 23, 13:05 UTCMay 24, 09:30 UTC20h 25m
2026-05-23 CSN6630 CGQ → HGH May 23, 12:50 UTCMay 24, 09:30 UTC20h 40m
2026-05-23 CSN6630 CGQ → HGH May 23, 07:00 UTCMay 23, 13:10 UTC6h 10m
2026-05-22 CSN6758 SZX → SYX May 22, 16:00 UTCMay 22, 16:10 UTC10m
2026-05-22 CSN6732 CAN → SYX May 22, 02:20 UTCMay 22, 02:40 UTC20m
2026-05-20 CSN6669 SYX → CGQ May 20, 17:10 UTCMay 21, 08:30 UTC15h 20m
2026-05-20 CSN6735 SYX → CAN May 20, 14:00 UTCMay 20, 14:15 UTC15m
2026-05-20 CSN6754 PVG → SYX May 20, 06:05 UTCMay 20, 07:15 UTC1h 10m
2026-05-19 CSN6754 PVG → SYX May 19, 09:10 UTCMay 20, 07:15 UTC22h 6m
2026-05-18 CSN6148 HRB → SYX May 18, 05:15 UTCMay 18, 10:05 UTC4h 50m
2026-05-17 CSN6758 SZX → SYX May 17, 15:35 UTCMay 17, 15:50 UTC15m
2026-05-17 CSN3978 SZX → SYX May 17, 03:25 UTCMay 17, 03:40 UTC15m
2026-05-17 CSN3977 SYX → SZX May 17, 00:05 UTCMay 17, 00:20 UTC15m
2026-05-15 CSN6758 SZX → SYX May 15, 16:35 UTCMay 15, 16:45 UTC10m
2026-05-15 CSN6754 PVG → SYX May 15, 01:05 UTCMay 15, 07:10 UTC6h 5m
2026-05-09 CSN6630 CGQ → HGH May 9, 07:10 UTCMay 9, 12:20 UTC5h 10m
2026-05-08 CSN6670 CGQ → SYX May 8, 09:04 UTCMay 9, 07:20 UTC22h 15m
2026-05-08 CSN6670 CGQ → SYX May 8, 04:29 UTCMay 8, 09:25 UTC4h 55m
2026-05-07 CSN6670 CGQ → SYX May 7, 14:05 UTCMay 8, 09:25 UTC19h 20m
2026-05-06 CSN6736 CAN → SYX May 6, 15:50 UTCMay 7, 09:35 UTC17h 45m
2026-05-05 CSN6758 SZX → SYX May 5, 15:35 UTCMay 6, 08:40 UTC17h 5m
2026-05-04 CSN6762 SHE → SYX May 4, 14:10 UTCMay 5, 08:25 UTC18h 16m
2026-05-04 CSN5671 CAN → JNG May 4, 11:55 UTCMay 4, 12:05 UTC10m
2026-05-04 CSN6323 - May 4, 05:15 UTCMay 4, 09:30 UTC4h 15m
2026-05-02 CSN6782 PVG → SYX May 2, 09:05 UTCMay 3, 04:35 UTC19h 29m
2026-04-29 CSN6147 SYX → HRB Apr 29, 07:24 UTCApr 29, 07:40 UTC15m
2026-04-26 CSN6670 CGQ → SYX Apr 26, 15:45 UTCApr 27, 09:35 UTC17h 50m
2026-04-26 CSN6757 SYX → SZX Apr 26, 14:05 UTCApr 26, 14:25 UTC20m
2026-04-25 CSN6758 SZX → SYX Apr 25, 15:30 UTCApr 26, 08:30 UTC17h 0m
2026-04-25 CSN3370 CGQ → SZX Apr 25, 13:00 UTCApr 25, 13:20 UTC20m
2026-04-25 CSN3369 SZX → CGQ Apr 25, 06:45 UTCApr 25, 11:00 UTC4h 15m
2026-04-25 CSN3369 SZX → CGQ Apr 25, 04:15 UTCApr 25, 04:25 UTC10m
2026-04-25 CSN3642 SYX → CGO Apr 25, 02:15 UTCApr 25, 02:30 UTC15m
2026-04-24 CSN3641 SZX → CKG Apr 24, 16:55 UTCApr 24, 17:10 UTC15m
2026-04-24 CSN6757 SYX → SZX Apr 24, 14:55 UTCApr 24, 15:15 UTC20m
2026-04-24 CSN6762 SHE → SYX Apr 24, 08:00 UTCApr 24, 08:25 UTC25m
2026-04-23 CSN6758 SZX → SYX Apr 23, 22:40 UTCApr 23, 23:00 UTC20m
2026-04-23 CSN6757 SYX → SZX Apr 23, 20:55 UTCApr 23, 21:05 UTC10m
2026-04-22 CSN6148 HRB → SYX Apr 22, 13:15 UTCApr 23, 08:20 UTC19h 5m
2026-04-22 CSN6148 HRB → SYX Apr 22, 05:45 UTCApr 23, 04:55 UTC23h 10m
2026-04-21 CSN6670 CGQ → SYX Apr 21, 09:15 UTCApr 22, 05:55 UTC20h 40m

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 B-32JZ page for operator, model, and routing details .

Mode-S 7821B4 frequently asked

What is Mode-S code 7821B4?
7821B4 is an ICAO 24-bit transponder address. Allocated to China. Assigned to B-32JZ.
Where is Mode-S 7821B4 registered?
Mode-S code 7821B4 is allocated to China (CN). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 7821B4 broadcasting right now?
No active broadcast right now. Last signal was 4h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 7821B4, octal 36020664, decimal 7,872,948.
What flights does 7821B4 operate?
Mode-S 7821B4 has broadcast 20 distinct callsigns, including CSN6670, CSN6758, CSN6757, CSN6630, CSN6754.