sensors Mode-S transponder
781551
ICAO 24-bit transponder address · allocated to China
Currently assigned to B-303L · AIRBUS A-321neo
- Hex
- 781551
- Octal
- 36012521
- Decimal
- 7,869,777
- Country
- CN
- Tail
- B-303L
- Type
- A21N
- Flights observed
- 77
- Distinct callsigns
- 20
- Country
- CN
- Last broadcast
- 6h ago
Last known position
Country allocation
The ICAO 24-bit address 781551 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 |
|---|---|---|---|
| CSN672 | - | 21 | 2026-07-18 |
| CSN671 | - | 19 | 2026-07-17 |
| CSN6519 | - | 3 | 2026-07-16 |
| CSN6456 | China Southern Airlines | 3 | 2026-05-25 |
| CSN6403 | - | 3 | 2026-07-18 |
| CSN6414 | - | 2 | 2026-06-28 |
| CSN6401 | China Southern Airlines | 2 | 2026-05-26 |
| CSN6315 | China Southern Airlines | 2 | 2026-05-07 |
| CSN6311 | China Southern Airlines | 2 | 2026-05-11 |
| CSN6309 | China Southern Airlines | 2 | 2026-06-13 |
| CSN6304 | - | 2 | 2026-06-24 |
| CSN6303 | - | 2 | 2026-06-24 |
| CSN6517 | China Southern Airlines | 1 | 2026-04-28 |
| CSN6507 | China Southern Airlines | 1 | 2026-05-14 |
| CSN6469 | China Southern Airlines | 1 | 2026-05-25 |
| CSN6451 | - | 1 | 2026-07-07 |
| CSN6402 | China Southern Airlines | 1 | 2026-04-26 |
| CSN6312 | China Southern Airlines | 1 | 2026-05-11 |
| CSN6310 | China Southern Airlines | 1 | 2026-06-13 |
| CSN6152 | China Southern Airlines | 1 | 2026-06-30 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-18 | CSN672 | - | Jul 18, 12:55 UTC | Jul 18, 13:25 UTC | 30m |
| 2026-07-18 | CSN6403 | - | Jul 18, 01:30 UTC | Jul 18, 11:10 UTC | 9h 41m |
| 2026-07-17 | CSN672 | ICN → ICN | Jul 17, 12:50 UTC | Jul 18, 11:10 UTC | 22h 21m |
| 2026-07-17 | CSN671 | - | Jul 17, 07:30 UTC | Jul 17, 11:20 UTC | 3h 50m |
| 2026-07-16 | CSN6519 | - | Jul 16, 10:25 UTC | Jul 17, 07:50 UTC | 21h 25m |
| 2026-07-16 | CSN6519 | - | Jul 16, 10:04 UTC | Jul 17, 07:50 UTC | 21h 45m |
| 2026-07-16 | CSN6519 | - | Jul 16, 05:40 UTC | Jul 16, 10:35 UTC | 4h 55m |
| 2026-07-08 | CSN5811 | - | Jul 8, 04:20 UTC | Jul 8, 05:05 UTC | 45m |
| 2026-07-07 | CSN6451 | - | Jul 7, 01:50 UTC | Jul 7, 02:35 UTC | 45m |
| 2026-06-30 | CSN6152 | CGO → SHE | Jun 30, 14:50 UTC | Jul 1, 04:40 UTC | 13h 50m |
| 2026-06-28 | CSN6414 | - | Jun 28, 05:34 UTC | Jun 28, 05:49 UTC | 15m |
| 2026-06-27 | CSN6414 | - | Jun 27, 06:35 UTC | Jun 28, 05:49 UTC | 23h 15m |
| 2026-06-25 | CSN6403 | - | Jun 25, 01:24 UTC | Jun 25, 10:45 UTC | 9h 20m |
| 2026-06-24 | CSN6403 | - | Jun 24, 15:35 UTC | Jun 25, 10:45 UTC | 19h 10m |
| 2026-06-24 | CSN6304 | - | Jun 24, 13:10 UTC | Jun 24, 13:24 UTC | 15m |
| 2026-06-24 | CSN6303 | - | Jun 24, 11:20 UTC | Jun 24, 11:34 UTC | 15m |
| 2026-06-24 | CSN6303 | - | Jun 24, 00:59 UTC | Jun 24, 09:05 UTC | 8h 5m |
| 2026-06-16 | CSN340 | - | Jun 16, 01:00 UTC | Jun 16, 01:45 UTC | 45m |
| 2026-06-15 | CSN339 | - | Jun 15, 12:05 UTC | Jun 15, 12:39 UTC | 35m |
| 2026-06-13 | CSN6310 | SZX → SHE | Jun 13, 10:20 UTC | Jun 13, 10:30 UTC | 10m |
| 2026-06-13 | CSN6309 | SHE → SZX | Jun 13, 08:00 UTC | Jun 13, 08:10 UTC | 10m |
| 2026-06-12 | CSN6309 | SHE → SZX | Jun 12, 12:45 UTC | Jun 13, 05:25 UTC | 16h 39m |
| 2026-06-08 | CSN672 | ICN → SHE | Jun 8, 12:55 UTC | Jun 8, 13:15 UTC | 20m |
| 2026-06-08 | CSN671 | SHE → ICN | Jun 8, 10:40 UTC | Jun 8, 11:00 UTC | 20m |
| 2026-06-07 | CSN672 | ICN → SHE | Jun 7, 13:05 UTC | Jun 8, 07:40 UTC | 18h 35m |
| 2026-06-07 | CSN671 | SHE → ICN | Jun 7, 11:00 UTC | Jun 7, 11:15 UTC | 15m |
| 2026-06-05 | CSN672 | ICN → SHE | Jun 5, 13:00 UTC | Jun 6, 08:30 UTC | 19h 30m |
| 2026-06-05 | CSN671 | SHE → ICN | Jun 5, 10:50 UTC | Jun 5, 11:20 UTC | 30m |
| 2026-06-04 | CSN672 | ICN → SHE | Jun 4, 12:55 UTC | Jun 5, 07:25 UTC | 18h 30m |
| 2026-06-04 | CSN671 | SHE → ICN | Jun 4, 10:50 UTC | Jun 4, 11:15 UTC | 25m |
| 2026-06-03 | CSN672 | ICN → SHE | Jun 3, 13:00 UTC | Jun 4, 07:45 UTC | 18h 45m |
| 2026-06-03 | CSN671 | SHE → ICN | Jun 3, 10:50 UTC | Jun 3, 11:15 UTC | 25m |
| 2026-06-02 | CSN672 | ICN → SHE | Jun 2, 12:50 UTC | Jun 3, 07:40 UTC | 18h 50m |
| 2026-06-02 | CSN671 | SHE → ICN | Jun 2, 10:50 UTC | Jun 2, 11:10 UTC | 20m |
| 2026-06-01 | CSN672 | ICN → SHE | Jun 1, 12:55 UTC | Jun 1, 13:20 UTC | 25m |
| 2026-06-01 | CSN671 | SHE → ICN | Jun 1, 10:50 UTC | Jun 1, 11:10 UTC | 20m |
| 2026-05-30 | CSN672 | ICN → SHE | May 30, 12:55 UTC | May 30, 13:25 UTC | 30m |
| 2026-05-30 | CSN671 | SHE → ICN | May 30, 07:30 UTC | May 30, 11:15 UTC | 3h 45m |
| 2026-05-28 | CSN672 | ICN → SHE | May 28, 13:00 UTC | May 29, 05:05 UTC | 16h 5m |
| 2026-05-28 | CSN671 | SHE → ICN | May 28, 10:50 UTC | May 28, 11:15 UTC | 25m |
| 2026-05-27 | CSN672 | ICN → SHE | May 27, 13:00 UTC | May 27, 13:20 UTC | 20m |
| 2026-05-27 | CSN671 | SHE → ICN | May 27, 10:55 UTC | May 27, 11:20 UTC | 25m |
| 2026-05-26 | CSN6401 | SHE → TFU | May 26, 10:54 UTC | May 27, 01:44 UTC | 14h 50m |
| 2026-05-26 | CSN6401 | SHE → TFU | May 26, 05:00 UTC | May 27, 01:44 UTC | 20h 45m |
| 2026-05-25 | CSN6469 | SHE → CKG | May 25, 14:20 UTC | May 26, 11:09 UTC | 20h 50m |
| 2026-05-25 | CSN6456 | XIY → SHE | May 25, 02:00 UTC | May 25, 14:30 UTC | 12h 30m |
| 2026-05-22 | CSN672 | ICN → SHE | May 22, 13:05 UTC | May 22, 13:25 UTC | 20m |
| 2026-05-22 | CSN671 | SHE → ICN | May 22, 11:05 UTC | May 22, 11:35 UTC | 30m |
| 2026-05-21 | CSN5857 | SHE → HGH | May 21, 08:10 UTC | May 21, 08:35 UTC | 25m |
| 2026-05-17 | CSN6456 | XIY → SHE | May 17, 15:10 UTC | May 18, 10:05 UTC | 18h 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 B-303L page for operator, model, and routing details .