sensors Mode-S transponder
781CB2
ICAO 24-bit transponder address · allocated to China
Currently assigned to B-221K · BOEING 767-300
- Hex
- 781CB2
- Octal
- 36016262
- Decimal
- 7,871,666
- Country
- CN
- Tail
- B-221K
- Type
- B763
- Flights observed
- 62
- Distinct callsigns
- 20
- Country
- CN
- Last broadcast
- 20h ago
Last known position
Country allocation
The ICAO 24-bit address 781CB2 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 | 6 | 2026-05-27 |
| CSS231 | SF Airlines | 6 | 2026-05-28 |
| CSS242 | - | 5 | 2026-05-27 |
| CSS239 | SF Airlines | 4 | 2026-06-01 |
| CSS232 | - | 4 | 2026-05-28 |
| CSS161 | SF Airlines | 4 | 2026-05-18 |
| CSS257 | - | 3 | 2026-04-28 |
| CSS255 | - | 3 | 2026-04-18 |
| CSS254 | - | 3 | 2026-05-22 |
| CSS253 | - | 3 | 2026-05-22 |
| CSS240 | - | 3 | 2026-05-31 |
| CSS7103 | SF Airlines | 2 | 2026-05-29 |
| CSS173 | - | 2 | 2026-05-03 |
| CSS169 | SF Airlines | 2 | 2026-05-06 |
| CSS167 | - | 2 | 2026-05-19 |
| CSS258 | - | 1 | 2026-04-28 |
| CSS256 | - | 1 | 2026-04-19 |
| CSS174 | - | 1 | 2026-05-03 |
| CSS168 | SF Airlines | 1 | 2026-05-20 |
| CSS162 | SF Airlines | 1 | 2026-05-17 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-06-01 | CSS148 | - | Jun 1, 20:40 UTC | Jun 1, 22:30 UTC | 1h 50m |
| 2026-06-01 | CSS239 | ZUH → DEL | Jun 1, 13:50 UTC | Jun 1, 18:30 UTC | 4h 40m |
| 2026-05-31 | CSS240 | - | May 31, 20:25 UTC | May 31, 22:25 UTC | 2h 0m |
| 2026-05-31 | CSS159 | EHU → DEL | May 31, 15:50 UTC | May 31, 18:15 UTC | 2h 25m |
| 2026-05-29 | CSS7103 | PEK → EHU | May 29, 16:40 UTC | May 29, 16:55 UTC | 15m |
| 2026-05-28 | CSS232 | - | May 28, 07:40 UTC | May 28, 10:35 UTC | 2h 55m |
| 2026-05-28 | CSS231 | CTU → BOM | May 28, 04:20 UTC | May 28, 04:35 UTC | 15m |
| 2026-05-27 | CSS242 | - | May 27, 08:35 UTC | May 28, 02:35 UTC | 18h 0m |
| 2026-05-27 | CSS242 | - | May 27, 08:20 UTC | May 28, 02:35 UTC | 18h 15m |
| 2026-05-27 | CSS241 | CTU → DEL | May 27, 03:54 UTC | May 27, 06:15 UTC | 2h 20m |
| 2026-05-22 | CSS254 | - | May 22, 07:20 UTC | May 22, 09:50 UTC | 2h 30m |
| 2026-05-22 | CSS253 | - | May 22, 05:00 UTC | May 22, 05:20 UTC | 20m |
| 2026-05-22 | CSS253 | - | May 22, 02:45 UTC | May 22, 03:20 UTC | 35m |
| 2026-05-20 | CSS168 | HAN → EHU | May 20, 05:50 UTC | May 20, 08:15 UTC | 2h 25m |
| 2026-05-19 | CSS167 | - | May 19, 15:30 UTC | May 20, 03:45 UTC | 12h 15m |
| 2026-05-19 | CSS239 | ZUH → DEL | May 19, 11:15 UTC | May 19, 13:30 UTC | 2h 15m |
| 2026-05-19 | CSS240 | - | May 19, 00:30 UTC | May 19, 02:15 UTC | 1h 45m |
| 2026-05-18 | CSS161 | EHU → DEL | May 18, 20:35 UTC | May 18, 22:45 UTC | 2h 10m |
| 2026-05-17 | CSS162 | DEL → EHU | May 17, 01:00 UTC | May 17, 18:10 UTC | 17h 10m |
| 2026-05-16 | CSS161 | EHU → DEL | May 16, 02:45 UTC | May 16, 22:30 UTC | 19h 45m |
| 2026-05-15 | CSS167 | - | May 15, 21:55 UTC | May 16, 00:40 UTC | 2h 45m |
| 2026-05-14 | CSS231 | CTU → BOM | May 14, 01:55 UTC | May 14, 11:30 UTC | 9h 35m |
| 2026-05-13 | CSS254 | - | May 13, 08:35 UTC | May 14, 03:15 UTC | 18h 40m |
| 2026-05-13 | CSS254 | - | May 13, 07:45 UTC | May 14, 03:15 UTC | 19h 30m |
| 2026-05-13 | CSS253 | - | May 13, 02:55 UTC | May 13, 05:40 UTC | 2h 45m |
| 2026-05-08 | CSS7103 | PEK → EHU | May 8, 16:55 UTC | May 8, 17:05 UTC | 10m |
| 2026-05-06 | CSS169 | EHU → MAA | May 6, 11:05 UTC | May 6, 18:05 UTC | 6h 59m |
| 2026-05-05 | CSS169 | EHU → MAA | May 5, 16:35 UTC | May 6, 13:15 UTC | 20h 40m |
| 2026-05-05 | CSS160 | DEL → EHU | May 5, 15:35 UTC | May 6, 13:15 UTC | 21h 40m |
| 2026-05-05 | CSS239 | ZUH → DEL | May 5, 10:05 UTC | May 5, 13:20 UTC | 3h 15m |
| 2026-05-05 | CSS239 | ZUH → DEL | May 5, 07:50 UTC | May 5, 07:55 UTC | 5m |
| 2026-05-05 | CSS240 | - | May 5, 00:35 UTC | May 5, 02:35 UTC | 2h 0m |
| 2026-05-04 | CSS161 | EHU → DEL | May 4, 20:25 UTC | May 4, 22:55 UTC | 2h 30m |
| 2026-05-03 | CSS161 | EHU → DEL | May 3, 22:34 UTC | May 4, 22:30 UTC | 23h 56m |
| 2026-05-03 | CSS174 | - | May 3, 21:00 UTC | May 4, 20:30 UTC | 23h 31m |
| 2026-05-03 | CSS173 | - | May 3, 18:30 UTC | May 3, 18:40 UTC | 10m |
| 2026-05-03 | CSS173 | - | May 3, 16:05 UTC | May 3, 17:45 UTC | 1h 40m |
| 2026-05-02 | CSS156 | LHE → EHU | May 2, 13:25 UTC | May 2, 15:40 UTC | 2h 15m |
| 2026-05-02 | CSS155 | EHU → LHE | May 2, 07:40 UTC | May 2, 10:40 UTC | 3h 0m |
| 2026-04-28 | CSS258 | - | Apr 28, 07:20 UTC | Apr 28, 07:50 UTC | 30m |
| 2026-04-28 | CSS257 | - | Apr 28, 04:35 UTC | Apr 28, 05:35 UTC | 1h 0m |
| 2026-04-27 | CSS232 | - | Apr 27, 10:05 UTC | Apr 27, 11:20 UTC | 1h 15m |
| 2026-04-27 | CSS232 | - | Apr 27, 08:55 UTC | Apr 27, 09:05 UTC | 10m |
| 2026-04-27 | CSS231 | CTU → BOM | Apr 27, 05:20 UTC | Apr 27, 05:35 UTC | 15m |
| 2026-04-27 | CSS231 | CTU → BOM | Apr 27, 02:05 UTC | Apr 27, 03:45 UTC | 1h 40m |
| 2026-04-24 | CSS242 | - | Apr 24, 08:00 UTC | Apr 24, 10:20 UTC | 2h 20m |
| 2026-04-23 | CSS241 | CTU → DEL | Apr 23, 10:35 UTC | Apr 24, 06:05 UTC | 19h 30m |
| 2026-04-23 | CSS241 | CTU → DEL | Apr 23, 09:45 UTC | Apr 24, 06:05 UTC | 20h 20m |
| 2026-04-23 | CSS232 | - | Apr 23, 08:20 UTC | Apr 23, 08:35 UTC | 15m |
| 2026-04-23 | CSS231 | CTU → BOM | Apr 23, 05:15 UTC | Apr 23, 05:30 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-221K page for operator, model, and routing details .