sensors Mode-S transponder
781C31
ICAO 24-bit transponder address · allocated to China
Currently assigned to B-325K · AIRBUS A-321neo
- Hex
- 781C31
- Octal
- 36016061
- Decimal
- 7,871,537
- Country
- CN
- Tail
- B-325K
- Type
- A21N
- Flights observed
- 45
- Distinct callsigns
- 14
- Country
- CN
- Last broadcast
- 3d ago
Last known position
Country allocation
The ICAO 24-bit address 781C31 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 14 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| CDC8787 | - | 7 | 2026-05-20 |
| CDC8737 | Zhejiang Loong Airlines | 7 | 2026-05-20 |
| CDC8738 | Zhejiang Loong Airlines | 6 | 2026-05-29 |
| CDC8630 | - | 5 | 2026-04-18 |
| CDC8629 | - | 4 | 2026-04-18 |
| CDC8206 | Zhejiang Loong Airlines | 4 | 2026-05-20 |
| CDC8788 | - | 3 | 2026-05-16 |
| CDC8859 | Zhejiang Loong Airlines | 2 | 2026-05-30 |
| CDC8992 | Zhejiang Loong Airlines | 1 | 2026-04-24 |
| CDC8989 | Zhejiang Loong Airlines | 1 | 2026-05-05 |
| CDC8700 | Zhejiang Loong Airlines | 1 | 2026-04-26 |
| CDC8231 | Zhejiang Loong Airlines | 1 | 2026-04-18 |
| CDC8008 | Zhejiang Loong Airlines | 1 | 2026-04-24 |
| CDC8007 | Zhejiang Loong Airlines | 1 | 2026-04-24 |
Recent flights last 45
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-30 | CDC8859 | HGH → CAN | May 30, 08:10 UTC | May 30, 09:05 UTC | 55m |
| 2026-05-29 | CDC8738 | SZX → HGH | May 29, 17:05 UTC | May 29, 17:20 UTC | 15m |
| 2026-05-27 | CDC8738 | SZX → HGH | May 27, 14:35 UTC | May 27, 14:45 UTC | 10m |
| 2026-05-24 | CDC8738 | SZX → HGH | May 24, 16:20 UTC | May 24, 16:35 UTC | 15m |
| 2026-05-20 | CDC8206 | HRB → HGH | May 20, 12:55 UTC | May 20, 13:40 UTC | 45m |
| 2026-05-20 | CDC8787 | - | May 20, 05:25 UTC | May 20, 05:35 UTC | 10m |
| 2026-05-20 | CDC8737 | HGH → SZX | May 20, 02:50 UTC | May 20, 03:10 UTC | 20m |
| 2026-05-19 | CDC8206 | HRB → HGH | May 19, 12:00 UTC | May 19, 12:10 UTC | 10m |
| 2026-05-19 | CDC8787 | - | May 19, 04:50 UTC | May 19, 05:05 UTC | 15m |
| 2026-05-19 | CDC8737 | HGH → SZX | May 19, 02:45 UTC | May 19, 03:05 UTC | 20m |
| 2026-05-16 | CDC8738 | SZX → HGH | May 16, 14:46 UTC | May 16, 14:55 UTC | 10m |
| 2026-05-16 | CDC8788 | - | May 16, 12:35 UTC | May 16, 12:45 UTC | 10m |
| 2026-05-15 | CDC8738 | SZX → HGH | May 15, 15:40 UTC | May 15, 15:50 UTC | 10m |
| 2026-05-13 | CDC8206 | HRB → HGH | May 13, 12:10 UTC | May 13, 13:00 UTC | 50m |
| 2026-05-13 | CDC8787 | - | May 13, 04:40 UTC | May 13, 04:55 UTC | 15m |
| 2026-05-13 | CDC8737 | HGH → SZX | May 13, 02:50 UTC | May 13, 03:10 UTC | 20m |
| 2026-05-10 | CDC8738 | SZX → HGH | May 10, 14:40 UTC | May 10, 14:49 UTC | 10m |
| 2026-05-10 | CDC8788 | - | May 10, 12:34 UTC | May 10, 12:54 UTC | 20m |
| 2026-05-08 | CDC8859 | HGH → CAN | May 8, 09:25 UTC | May 8, 09:34 UTC | 10m |
| 2026-05-07 | CDC8787 | - | May 7, 04:35 UTC | May 7, 04:50 UTC | 15m |
| 2026-05-07 | CDC8737 | HGH → SZX | May 7, 02:30 UTC | May 7, 02:55 UTC | 25m |
| 2026-05-05 | CDC8989 | HGH → CAN | May 5, 16:35 UTC | May 5, 16:55 UTC | 20m |
| 2026-05-04 | CDC8787 | - | May 4, 04:24 UTC | May 4, 04:34 UTC | 10m |
| 2026-05-04 | CDC8737 | HGH → SZX | May 4, 02:35 UTC | May 4, 02:54 UTC | 20m |
| 2026-05-03 | CDC8787 | - | May 3, 05:45 UTC | May 3, 05:55 UTC | 10m |
| 2026-05-03 | CDC8737 | HGH → SZX | May 3, 02:45 UTC | May 3, 03:35 UTC | 49m |
| 2026-04-26 | CDC8700 | CAN → HGH | Apr 26, 07:00 UTC | Apr 26, 07:10 UTC | 10m |
| 2026-04-25 | - | - | Apr 25, 16:35 UTC | Apr 25, 16:45 UTC | 10m |
| 2026-04-24 | CDC8992 | HRB → HGH | Apr 24, 14:40 UTC | Apr 25, 07:10 UTC | 16h 30m |
| 2026-04-24 | CDC8008 | HKG → HGH | Apr 24, 06:30 UTC | Apr 24, 15:15 UTC | 8h 45m |
| 2026-04-24 | CDC8007 | HGH → HKG | Apr 24, 04:05 UTC | Apr 24, 04:40 UTC | 35m |
| 2026-04-22 | CDC8788 | - | Apr 22, 12:30 UTC | Apr 22, 12:50 UTC | 20m |
| 2026-04-21 | CDC8206 | HRB → HGH | Apr 21, 13:20 UTC | Apr 21, 14:05 UTC | 45m |
| 2026-04-21 | CDC8787 | - | Apr 21, 05:45 UTC | Apr 21, 06:05 UTC | 20m |
| 2026-04-21 | CDC8737 | HGH → SZX | Apr 21, 03:05 UTC | Apr 21, 03:15 UTC | 10m |
| 2026-04-18 | CDC8231 | HRB → HGH | Apr 18, 23:25 UTC | Apr 19, 08:30 UTC | 9h 5m |
| 2026-04-18 | CDC8630 | - | Apr 18, 10:20 UTC | Apr 18, 10:30 UTC | 10m |
| 2026-04-18 | CDC8629 | - | Apr 18, 07:00 UTC | Apr 18, 07:20 UTC | 20m |
| 2026-04-17 | CDC8629 | - | Apr 17, 07:30 UTC | Apr 17, 07:40 UTC | 10m |
| 2026-04-16 | CDC8630 | - | Apr 16, 11:20 UTC | Apr 16, 11:35 UTC | 15m |
| 2026-04-16 | CDC8629 | - | Apr 16, 09:29 UTC | Apr 16, 09:54 UTC | 25m |
| 2026-04-15 | CDC8630 | - | Apr 15, 10:30 UTC | Apr 15, 10:40 UTC | 10m |
| 2026-04-15 | CDC8629 | - | Apr 15, 08:20 UTC | Apr 15, 08:40 UTC | 20m |
| 2026-04-14 | CDC8630 | - | Apr 14, 09:55 UTC | Apr 14, 10:10 UTC | 15m |
| 2026-04-13 | CDC8630 | - | Apr 13, 10:15 UTC | Apr 13, 10:25 UTC | 10m |
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-325K page for operator, model, and routing details .