sensors Mode-S transponder
781683
ICAO 24-bit transponder address · allocated to China
Currently assigned to B-20A8 · BOEING 737-800
- Hex
- 781683
- Octal
- 36013203
- Decimal
- 7,870,083
- Country
- CN
- Tail
- B-20A8
- Type
- B738
- Flights observed
- 15
- Distinct callsigns
- 13
- Country
- CN
- Last broadcast
- 17h ago
Last known position
Country allocation
The ICAO 24-bit address 781683 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 13 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| CUA5802 | China United Airlines | 2 | 2026-06-21 |
| CUA5567 | - | 2 | 2026-05-22 |
| CUA5686 | China United Airlines | 1 | 2026-05-26 |
| CUA5685 | China United Airlines | 1 | 2026-05-26 |
| CUA5630 | China United Airlines | 1 | 2026-05-01 |
| CUA5606 | - | 1 | 2026-06-12 |
| CUA5602 | China United Airlines | 1 | 2026-05-09 |
| CUA5597 | China United Airlines | 1 | 2026-05-17 |
| CUA5595 | China United Airlines | 1 | 2026-04-29 |
| CUA5569 | China United Airlines | 1 | 2026-04-22 |
| CUA5529 | - | 1 | 2026-06-22 |
| CUA5375 | China United Airlines | 1 | 2026-04-27 |
| CUA2917 | China United Airlines | 1 | 2026-06-18 |
Recent flights last 15
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-06-22 | CUA5529 | - | Jun 22, 10:30 UTC | Jun 22, 10:55 UTC | 25m |
| 2026-06-21 | CUA5802 | DSN → PKX | Jun 21, 05:25 UTC | Jun 21, 05:40 UTC | 15m |
| 2026-06-18 | CUA2917 | PVG → HUZ | Jun 18, 15:50 UTC | Jun 18, 16:45 UTC | 55m |
| 2026-06-12 | CUA5606 | - | Jun 12, 11:35 UTC | Jun 12, 11:50 UTC | 15m |
| 2026-05-26 | CUA5686 | HMI → PKX | May 26, 14:30 UTC | May 26, 14:40 UTC | 10m |
| 2026-05-26 | CUA5685 | PKX → HMI | May 26, 07:59 UTC | May 26, 08:15 UTC | 15m |
| 2026-05-22 | CUA5567 | - | May 22, 02:00 UTC | May 22, 02:15 UTC | 15m |
| 2026-05-17 | CUA5597 | PKX → JMU | May 17, 09:40 UTC | May 17, 09:50 UTC | 10m |
| 2026-05-09 | CUA5602 | YZY → PKX | May 9, 14:10 UTC | May 9, 14:25 UTC | 15m |
| 2026-05-09 | CUA5567 | - | May 9, 02:00 UTC | May 9, 02:15 UTC | 15m |
| 2026-05-08 | CUA5802 | DSN → PKX | May 8, 05:54 UTC | May 8, 06:09 UTC | 15m |
| 2026-05-01 | CUA5630 | XNN → PKX | May 1, 13:25 UTC | May 1, 13:40 UTC | 15m |
| 2026-04-29 | CUA5595 | PKX → DBC | Apr 29, 23:45 UTC | Apr 29, 23:55 UTC | 10m |
| 2026-04-27 | CUA5375 | PKX → HSN | Apr 27, 09:20 UTC | Apr 27, 09:50 UTC | 30m |
| 2026-04-22 | CUA5569 | PKX → DQA | Apr 22, 05:10 UTC | Apr 22, 05:20 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-20A8 page for operator, model, and routing details .