sensors Mode-S transponder
781C40
ICAO 24-bit transponder address · allocated to China
Currently assigned to B-221D · BOEING 767-300
- Hex
- 781C40
- Octal
- 36016100
- Decimal
- 7,871,552
- Country
- CN
- Tail
- B-221D
- Type
- B763
- Flights observed
- 51
- Distinct callsigns
- 20
- Country
- CN
- Last broadcast
- 8h ago
Last known position
Country allocation
The ICAO 24-bit address 781C40 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 |
|---|---|---|---|
| CSS241 | SF Airlines | 7 | 2026-05-22 |
| CSS242 | - | 5 | 2026-05-22 |
| CSS237 | SF Airlines | 4 | 2026-05-30 |
| CSS253 | - | 3 | 2026-05-29 |
| CSS231 | SF Airlines | 3 | 2026-05-18 |
| CSS7223 | SF Airlines | 2 | 2026-04-19 |
| CSS364 | SF Airlines | 2 | 2026-05-27 |
| CSS363 | SF Airlines | 2 | 2026-05-26 |
| CSS357 | SF Airlines | 2 | 2026-05-25 |
| CSS254 | - | 2 | 2026-05-29 |
| CSS232 | - | 2 | 2026-05-04 |
| CSS161 | SF Airlines | 2 | 2026-04-23 |
| CSS7635 | SF Airlines | 1 | 2026-06-02 |
| CSS6835 | SF Airlines | 1 | 2026-04-19 |
| CSS6805 | SF Airlines | 1 | 2026-05-27 |
| CSS6804 | SF Airlines | 1 | 2026-05-25 |
| CSS6801 | SF Airlines | 1 | 2026-04-17 |
| CSS358 | SF Airlines | 1 | 2026-05-26 |
| CSS258 | - | 1 | 2026-04-16 |
| CSS257 | - | 1 | 2026-04-16 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-06-02 | CSS7635 | SHE → EHU | Jun 2, 16:10 UTC | Jun 2, 22:10 UTC | 6h 0m |
| 2026-05-31 | CSS169 | EHU → MAA | May 31, 11:05 UTC | May 31, 17:35 UTC | 6h 30m |
| 2026-05-30 | CSS237 | CTU → MAA | May 30, 01:05 UTC | May 30, 08:20 UTC | 7h 15m |
| 2026-05-29 | CSS237 | CTU → MAA | May 29, 08:40 UTC | May 30, 07:45 UTC | 23h 5m |
| 2026-05-29 | CSS254 | - | May 29, 06:55 UTC | May 30, 02:55 UTC | 20h 0m |
| 2026-05-29 | CSS253 | - | May 29, 02:55 UTC | May 29, 04:35 UTC | 1h 40m |
| 2026-05-27 | CSS6805 | SZX → EHU | May 27, 16:55 UTC | May 27, 17:05 UTC | 10m |
| 2026-05-27 | CSS364 | NRT → SZX | May 27, 05:24 UTC | May 27, 05:35 UTC | 10m |
| 2026-05-27 | CSS364 | NRT → SZX | May 27, 01:29 UTC | May 27, 02:49 UTC | 1h 20m |
| 2026-05-26 | CSS363 | SZX → NRT | May 26, 21:40 UTC | May 26, 22:59 UTC | 1h 20m |
| 2026-05-26 | CSS363 | SZX → NRT | May 26, 19:15 UTC | May 26, 19:25 UTC | 10m |
| 2026-05-26 | CSS358 | TPE → SZX | May 26, 02:49 UTC | May 26, 04:04 UTC | 1h 15m |
| 2026-05-25 | CSS357 | SZX → TPE | May 25, 23:45 UTC | May 26, 00:29 UTC | 45m |
| 2026-05-25 | CSS357 | SZX → TPE | May 25, 23:00 UTC | May 25, 23:14 UTC | 15m |
| 2026-05-25 | CSS6804 | EHU → SZX | May 25, 20:45 UTC | May 25, 20:59 UTC | 15m |
| 2026-05-22 | CSS242 | - | May 22, 08:30 UTC | May 22, 10:20 UTC | 1h 49m |
| 2026-05-22 | CSS241 | CTU → DEL | May 22, 04:05 UTC | May 22, 06:25 UTC | 2h 20m |
| 2026-05-20 | CSS242 | - | May 20, 08:45 UTC | May 20, 10:50 UTC | 2h 5m |
| 2026-05-20 | CSS241 | CTU → DEL | May 20, 04:05 UTC | May 20, 06:20 UTC | 2h 16m |
| 2026-05-18 | CSS231 | CTU → BOM | May 18, 02:10 UTC | May 18, 09:55 UTC | 7h 45m |
| 2026-05-17 | CSS231 | CTU → BOM | May 17, 10:05 UTC | May 18, 09:55 UTC | 23h 50m |
| 2026-05-17 | CSS242 | - | May 17, 08:50 UTC | May 18, 02:55 UTC | 18h 5m |
| 2026-05-17 | CSS241 | CTU → DEL | May 17, 04:40 UTC | May 17, 06:00 UTC | 1h 20m |
| 2026-05-04 | CSS232 | - | May 4, 09:35 UTC | May 4, 10:40 UTC | 1h 5m |
| 2026-05-04 | CSS232 | - | May 4, 08:10 UTC | May 4, 08:20 UTC | 10m |
| 2026-05-04 | CSS231 | CTU → BOM | May 4, 04:44 UTC | May 4, 05:05 UTC | 20m |
| 2026-05-03 | CSS242 | - | May 3, 08:55 UTC | May 4, 03:19 UTC | 18h 25m |
| 2026-05-03 | CSS241 | CTU → DEL | May 3, 04:05 UTC | May 3, 06:55 UTC | 2h 50m |
| 2026-05-02 | CSS241 | CTU → DEL | May 2, 08:05 UTC | May 3, 06:55 UTC | 22h 49m |
| 2026-05-02 | CSS241 | CTU → DEL | May 2, 06:45 UTC | May 3, 06:00 UTC | 23h 14m |
| 2026-05-02 | CSS237 | CTU → MAA | May 2, 01:20 UTC | May 2, 08:05 UTC | 6h 46m |
| 2026-05-01 | CSS237 | CTU → MAA | May 1, 10:05 UTC | May 2, 08:05 UTC | 22h 0m |
| 2026-05-01 | CSS242 | - | May 1, 08:30 UTC | May 2, 08:00 UTC | 23h 30m |
| 2026-05-01 | CSS241 | CTU → DEL | May 1, 03:10 UTC | May 1, 06:25 UTC | 3h 15m |
| 2026-04-29 | CSS254 | - | Apr 29, 07:45 UTC | Apr 29, 09:55 UTC | 2h 11m |
| 2026-04-29 | CSS253 | - | Apr 29, 05:25 UTC | Apr 29, 05:35 UTC | 10m |
| 2026-04-29 | CSS253 | - | Apr 29, 03:04 UTC | Apr 29, 04:39 UTC | 1h 35m |
| 2026-04-26 | CSS158 | DEL → EHU | Apr 26, 12:05 UTC | Apr 26, 14:10 UTC | 2h 5m |
| 2026-04-25 | CSS239 | ZUH → DEL | Apr 25, 21:00 UTC | Apr 26, 09:20 UTC | 12h 20m |
| 2026-04-25 | CSS159 | EHU → DEL | Apr 25, 15:50 UTC | Apr 25, 18:30 UTC | 2h 40m |
| 2026-04-24 | CSS170 | - | Apr 24, 16:05 UTC | Apr 25, 16:00 UTC | 23h 55m |
| 2026-04-24 | CSS162 | DEL → EHU | Apr 24, 00:15 UTC | Apr 24, 17:40 UTC | 17h 25m |
| 2026-04-23 | CSS161 | EHU → DEL | Apr 23, 19:40 UTC | Apr 23, 22:25 UTC | 2h 45m |
| 2026-04-22 | CSS148 | - | Apr 22, 00:10 UTC | Apr 22, 18:20 UTC | 18h 10m |
| 2026-04-21 | CSS161 | EHU → DEL | Apr 21, 19:40 UTC | Apr 21, 22:25 UTC | 2h 45m |
| 2026-04-19 | CSS6835 | SZX → HGH | Apr 19, 20:45 UTC | Apr 19, 20:55 UTC | 10m |
| 2026-04-19 | CSS7223 | HGH → SZX | Apr 19, 18:45 UTC | Apr 19, 19:10 UTC | 25m |
| 2026-04-18 | CSS7223 | HGH → SZX | Apr 18, 18:20 UTC | Apr 18, 19:15 UTC | 55m |
| 2026-04-17 | CSS6801 | SZX → EHU | Apr 17, 17:40 UTC | Apr 17, 17:50 UTC | 10m |
| 2026-04-16 | CSS258 | - | Apr 16, 07:09 UTC | Apr 16, 07:49 UTC | 40m |
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-221D page for operator, model, and routing details .