sensors Mode-S transponder
781F04
ICAO 24-bit transponder address · allocated to China
Currently assigned to B-91A0 · COMAC ARJ-21-700 Xiangfeng
- Hex
- 781F04
- Octal
- 36017404
- Decimal
- 7,872,260
- Country
- CN
- Tail
- B-91A0
- Type
- AJ27
- Flights observed
- 17
- Distinct callsigns
- 10
- Country
- CN
- Last broadcast
- 20h ago
Last known position
Country allocation
The ICAO 24-bit address 781F04 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
Recent flights last 17
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-17 | CSN8549 | - | Jul 17, 07:50 UTC | Jul 17, 11:39 UTC | 3h 50m |
| 2026-07-11 | CSN3894 | - | Jul 11, 02:10 UTC | Jul 11, 02:35 UTC | 25m |
| 2026-07-10 | CSN5137 | - | Jul 10, 12:30 UTC | Jul 10, 15:25 UTC | 2h 55m |
| 2026-07-09 | CSN8550 | - | Jul 9, 10:30 UTC | Jul 9, 10:50 UTC | 20m |
| 2026-07-09 | CSN8549 | - | Jul 9, 06:20 UTC | Jul 9, 06:30 UTC | 10m |
| 2026-07-01 | CSN3714 | - | Jul 1, 04:30 UTC | Jul 1, 04:50 UTC | 20m |
| 2026-06-24 | CSN3636 | - | Jun 24, 16:14 UTC | Jun 24, 16:40 UTC | 25m |
| 2026-06-24 | CSN3150 | - | Jun 24, 09:00 UTC | Jun 24, 09:45 UTC | 45m |
| 2026-06-22 | CSN8213 | - | Jun 22, 01:55 UTC | Jun 22, 02:04 UTC | 10m |
| 2026-06-12 | CSN8549 | - | Jun 12, 06:15 UTC | Jun 12, 10:10 UTC | 3h 55m |
| 2026-05-31 | CSN3895 | - | May 31, 23:50 UTC | Jun 1, 00:15 UTC | 25m |
| 2026-05-29 | CSN8794 | PKX → ZUH | May 29, 11:40 UTC | May 29, 11:50 UTC | 10m |
| 2026-05-27 | CSN8549 | - | May 27, 06:15 UTC | May 27, 10:20 UTC | 4h 5m |
| 2026-05-08 | CSN8549 | - | May 8, 06:20 UTC | May 8, 10:09 UTC | 3h 50m |
| 2026-04-25 | CSN3895 | - | Apr 25, 00:10 UTC | Apr 25, 00:25 UTC | 15m |
| 2026-04-19 | CSN3895 | - | Apr 19, 00:05 UTC | Apr 19, 00:30 UTC | 25m |
| 2026-04-17 | CSN3895 | - | Apr 17, 00:10 UTC | Apr 17, 00:20 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-91A0 page for operator, model, and routing details .