sensors Mode-S transponder
781B59
ICAO 24-bit transponder address · allocated to China
Currently assigned to B-322W · AIRBUS A-321neo
- Hex
- 781B59
- Octal
- 36015531
- Decimal
- 7,871,321
- Country
- CN
- Tail
- B-322W
- Type
- A21N
- Flights observed
- 17
- Distinct callsigns
- 10
- Country
- CN
- Last broadcast
- 8d ago
Last known position
Country allocation
The ICAO 24-bit address 781B59 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 10 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| CCA4340 | Air China | 5 | 2026-06-01 |
| CCA4339 | Air China | 3 | 2026-05-12 |
| CCA4338 | Air China | 1 | 2026-05-10 |
| CCA4312 | Air China | 1 | 2026-04-28 |
| CCA4301 | Air China | 1 | 2026-05-23 |
| CCA4182 | Air China | 1 | 2026-04-26 |
| CCA4181 | Air China | 1 | 2026-04-26 |
| CCA4118 | Air China | 1 | 2026-05-19 |
| CCA4116 | Air China | 1 | 2026-04-27 |
| CCA4110 | Air China | 1 | 2026-05-18 |
Recent flights last 17
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-06-01 | CCA4340 | SZX → CTU | Jun 1, 23:30 UTC | Jun 1, 23:40 UTC | 10m |
| 2026-05-23 | CCA4301 | CTU → CAN | May 23, 11:40 UTC | May 23, 11:50 UTC | 10m |
| 2026-05-19 | CCA4118 | PEK → CTU | May 19, 14:00 UTC | May 19, 14:25 UTC | 25m |
| 2026-05-18 | CCA4110 | PEK → CTU | May 18, 11:45 UTC | May 18, 12:05 UTC | 20m |
| 2026-05-12 | CCA4340 | SZX → CTU | May 12, 23:20 UTC | May 12, 23:45 UTC | 25m |
| 2026-05-12 | CCA4339 | CTU → SZX | May 12, 15:05 UTC | May 12, 15:15 UTC | 10m |
| 2026-05-10 | CCA4338 | SZX → CTU | May 10, 03:20 UTC | May 10, 03:35 UTC | 15m |
| 2026-05-10 | - | - | May 10, 01:30 UTC | May 10, 01:39 UTC | 10m |
| 2026-05-06 | CCA4340 | SZX → CTU | May 6, 23:40 UTC | May 6, 23:55 UTC | 15m |
| 2026-04-28 | CCA4312 | SZX → CTU | Apr 28, 12:35 UTC | Apr 28, 12:45 UTC | 10m |
| 2026-04-27 | CCA4116 | PEK → CTU | Apr 27, 07:05 UTC | Apr 27, 07:15 UTC | 10m |
| 2026-04-26 | CCA4182 | PEK → CTU | Apr 26, 23:10 UTC | Apr 26, 23:35 UTC | 25m |
| 2026-04-26 | CCA4181 | CTU → PEK | Apr 26, 12:15 UTC | Apr 26, 12:25 UTC | 10m |
| 2026-04-21 | CCA4340 | SZX → CTU | Apr 21, 23:35 UTC | Apr 21, 23:45 UTC | 10m |
| 2026-04-21 | CCA4339 | CTU → SZX | Apr 21, 14:55 UTC | Apr 21, 15:05 UTC | 10m |
| 2026-04-19 | CCA4340 | SZX → CTU | Apr 19, 23:15 UTC | Apr 19, 23:25 UTC | 10m |
| 2026-04-19 | CCA4339 | CTU → SZX | Apr 19, 15:00 UTC | Apr 19, 15:15 UTC | 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-322W page for operator, model, and routing details .