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 7h ago
Flights observed
131
Distinct callsigns
20
Country
CN
Last broadcast
7h 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
CSN6754 - 10 2026-07-02
CSN6630 - 10 2026-07-09
CSN6148 - 9 2026-07-01
CSN6758 - 8 2026-07-10
CSN6712 China Southern Airlines 7 2026-06-25
CSN6757 China Southern Airlines 4 2026-04-26
CSN6716 China Southern Airlines 4 2026-06-26
CSN6700 China Southern Airlines 4 2026-06-20
CSN6624 - 4 2026-06-17
CSN6795 China Southern Airlines 3 2026-06-15
CSN6781 - 3 2026-07-08
CSN6762 - 3 2026-07-10
CSN6732 - 3 2026-07-06
CSN6718 China Southern Airlines 3 2026-06-24
CSN6668 - 3 2026-06-29
CSN6190 - 3 2026-07-04
CSN5785 China Southern Airlines 3 2026-06-27
CSN8920 China Southern Airlines 2 2026-06-16
CSN6736 China Southern Airlines 2 2026-05-06

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 CSN604 - Jul 14, 10:00 UTCJul 14, 10:25 UTC25m
2026-07-14 CSN603 - Jul 14, 07:45 UTCJul 14, 08:25 UTC40m
2026-07-10 CSN6758 - Jul 10, 15:45 UTCJul 10, 16:00 UTC15m
2026-07-10 CSN6762 - Jul 10, 04:30 UTCJul 10, 08:15 UTC3h 45m
2026-07-09 CSN6630 - Jul 9, 12:05 UTCJul 10, 08:15 UTC20h 10m
2026-07-09 CSN6630 - Jul 9, 07:10 UTCJul 10, 04:55 UTC21h 45m
2026-07-08 CSN6630 - Jul 8, 14:15 UTCJul 9, 12:25 UTC22h 10m
2026-07-08 CSN6781 - Jul 8, 09:20 UTCJul 9, 07:20 UTC22h 0m
2026-07-08 CSN6781 - Jul 8, 04:25 UTCJul 8, 14:35 UTC10h 10m
2026-07-06 CSN6732 - Jul 6, 02:50 UTCJul 6, 11:20 UTC8h 30m
2026-07-04 CSN6190 - Jul 4, 05:20 UTCJul 4, 13:00 UTC7h 40m
2026-07-03 CSN6228 - Jul 3, 07:05 UTCJul 4, 05:30 UTC22h 25m
2026-07-03 CSN6753 - Jul 3, 01:00 UTCJul 3, 07:10 UTC6h 10m
2026-07-02 CSN6754 - Jul 2, 05:50 UTCJul 3, 01:10 UTC19h 20m
2026-07-02 CSN6754 - Jul 2, 01:05 UTCJul 3, 01:00 UTC23h 55m
2026-07-02 CSN6754 - Jul 2, 00:55 UTCJul 2, 06:55 UTC6h 0m
2026-07-01 CSN6754 - Jul 1, 09:45 UTCJul 2, 06:55 UTC21h 10m
2026-07-01 CSN6148 - Jul 1, 05:20 UTCJul 2, 01:05 UTC19h 45m
2026-07-01 CSN6148 - Jul 1, 02:50 UTCJul 2, 00:55 UTC22h 5m
2026-06-30 CSN6190 - Jun 30, 00:25 UTCJun 30, 12:50 UTC12h 26m
2026-06-29 CSN6668 - Jun 29, 02:05 UTCJun 29, 12:49 UTC10h 45m
2026-06-28 CSN6190 - Jun 28, 00:15 UTCJun 28, 12:39 UTC12h 25m
2026-06-27 CSN5785 SYX → WUH Jun 27, 00:29 UTCJun 27, 14:54 UTC14h 25m
2026-06-26 CSN5785 SYX → WUH Jun 26, 14:19 UTCJun 27, 10:05 UTC19h 45m
2026-06-26 CSN6716 PKX → SYX Jun 26, 03:50 UTCJun 27, 01:09 UTC21h 20m
2026-06-25 CSN6717 SYX → PKX Jun 25, 10:20 UTCJun 26, 03:50 UTC17h 30m
2026-06-25 CSN6712 PKX → SYX Jun 25, 07:59 UTCJun 26, 03:50 UTC19h 50m
2026-06-25 CSN6712 PKX → SYX Jun 25, 00:49 UTCJun 25, 10:39 UTC9h 50m
2026-06-24 CSN6716 PKX → SYX Jun 24, 14:20 UTCJun 25, 10:39 UTC20h 20m
2026-06-24 CSN6716 PKX → SYX Jun 24, 06:39 UTCJun 25, 00:59 UTC18h 20m
2026-06-24 CSN6718 PKX → SYX Jun 24, 03:19 UTCJun 25, 00:59 UTC21h 40m
2026-06-24 CSN6718 PKX → SYX Jun 24, 00:49 UTCJun 24, 14:39 UTC13h 50m
2026-06-23 CSN6712 PKX → SYX Jun 23, 08:09 UTCJun 23, 08:30 UTC20m
2026-06-22 CSN6630 - Jun 22, 06:49 UTCJun 23, 00:50 UTC18h 0m
2026-06-22 CSN6630 - Jun 22, 03:30 UTCJun 23, 00:50 UTC21h 20m
2026-06-21 CSN6718 PKX → SYX Jun 21, 10:49 UTCJun 22, 07:00 UTC20h 10m
2026-06-21 CSN6712 PKX → SYX Jun 21, 08:15 UTCJun 22, 07:00 UTC22h 45m
2026-06-21 CSN6712 PKX → SYX Jun 21, 00:34 UTCJun 21, 10:54 UTC10h 20m
2026-06-20 CSN6668 NKG → SYX Jun 20, 12:14 UTCJun 21, 10:54 UTC22h 40m
2026-06-20 CSN6668 NKG → SYX Jun 20, 07:04 UTCJun 21, 00:49 UTC17h 45m
2026-06-20 CSN6700 KMG → SYX Jun 20, 03:49 UTCJun 21, 00:49 UTC21h 0m
2026-06-20 CSN6700 KMG → SYX Jun 20, 00:14 UTCJun 20, 12:54 UTC12h 40m
2026-06-19 CSN6700 KMG → SYX Jun 19, 14:15 UTCJun 20, 12:54 UTC22h 40m
2026-06-19 CSN6700 KMG → SYX Jun 19, 07:09 UTCJun 20, 04:29 UTC21h 20m
2026-06-19 CSN6699 SYX → KMG Jun 19, 04:10 UTCJun 20, 00:34 UTC20h 25m
2026-06-17 CSN6712 PKX → SYX Jun 17, 14:40 UTCJun 18, 08:15 UTC17h 35m
2026-06-17 CSN6712 PKX → SYX Jun 17, 09:20 UTCJun 18, 08:15 UTC22h 55m
2026-06-17 CSN6624 - Jun 17, 05:55 UTCJun 18, 00:50 UTC18h 55m
2026-06-16 CSN8920 XIY → SYX Jun 16, 00:20 UTCJun 16, 06:04 UTC5h 45m
2026-06-15 CSN6795 SYX → KWE Jun 15, 00:40 UTCJun 15, 14:55 UTC14h 15m

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 7h 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, CSN6754, CSN6630, CSN6148, CSN6758.