sensors Mode-S transponder
781CDF
ICAO 24-bit transponder address · allocated to China
Currently assigned to B-221A · BOEING 757-200
- Hex
- 781CDF
- Octal
- 36016337
- Decimal
- 7,871,711
- Country
- CN
- Tail
- B-221A
- Type
- B752
- Flights observed
- 167
- Distinct callsigns
- 13
- Country
- CN
- Last broadcast
- 27m ago
Last known position
Country allocation
The ICAO 24-bit address 781CDF 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 |
|---|---|---|---|
| HYT9103 | - | 30 | 2026-07-15 |
| HYT9068 | - | 28 | 2026-07-16 |
| HYT9157 | - | 25 | 2026-07-16 |
| HYT9104 | - | 20 | 2026-07-15 |
| HYT9130 | - | 16 | 2026-07-14 |
| HYT9158 | - | 15 | 2026-07-17 |
| HYT9067 | - | 11 | 2026-07-15 |
| HYT9129 | - | 10 | 2026-07-14 |
| HYT9089 | YTO Cargo Ltd | 3 | 2026-05-13 |
| HYT9076 | - | 3 | 2026-06-30 |
| HYT9075 | - | 3 | 2026-07-01 |
| HYT9083 | - | 2 | 2026-06-30 |
| HYT9090 | YTO Cargo Ltd | 1 | 2026-05-14 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-17 | HYT9158 | - | Jul 17, 06:35 UTC | Jul 18, 05:45 UTC | 23h 11m |
| 2026-07-16 | HYT9157 | - | Jul 16, 09:50 UTC | Jul 17, 05:10 UTC | 19h 20m |
| 2026-07-16 | HYT9157 | - | Jul 16, 08:50 UTC | Jul 17, 05:10 UTC | 20h 20m |
| 2026-07-16 | HYT9068 | - | Jul 16, 06:55 UTC | Jul 17, 05:10 UTC | 22h 15m |
| 2026-07-16 | HYT9068 | - | Jul 16, 04:00 UTC | Jul 17, 03:45 UTC | 23h 45m |
| 2026-07-16 | HYT9068 | - | Jul 16, 01:20 UTC | Jul 16, 10:40 UTC | 9h 20m |
| 2026-07-15 | HYT9067 | - | Jul 15, 09:50 UTC | Jul 16, 09:45 UTC | 23h 55m |
| 2026-07-15 | HYT9104 | - | Jul 15, 09:00 UTC | Jul 16, 07:25 UTC | 22h 25m |
| 2026-07-15 | HYT9104 | - | Jul 15, 07:30 UTC | Jul 16, 04:10 UTC | 20h 40m |
| 2026-07-15 | HYT9103 | - | Jul 15, 05:15 UTC | Jul 15, 05:40 UTC | 25m |
| 2026-07-15 | HYT9103 | - | Jul 15, 02:20 UTC | Jul 15, 04:05 UTC | 1h 45m |
| 2026-07-14 | HYT9103 | - | Jul 14, 07:50 UTC | Jul 15, 04:05 UTC | 20h 14m |
| 2026-07-14 | HYT9130 | - | Jul 14, 07:00 UTC | Jul 15, 04:05 UTC | 21h 4m |
| 2026-07-14 | HYT9130 | - | Jul 14, 03:50 UTC | Jul 15, 03:45 UTC | 23h 54m |
| 2026-07-14 | HYT9129 | - | Jul 14, 01:55 UTC | Jul 14, 09:10 UTC | 7h 15m |
| 2026-07-13 | HYT9129 | - | Jul 13, 09:50 UTC | Jul 14, 09:10 UTC | 23h 20m |
| 2026-07-13 | HYT9129 | - | Jul 13, 08:25 UTC | Jul 14, 07:45 UTC | 23h 20m |
| 2026-07-13 | HYT9158 | - | Jul 13, 07:15 UTC | Jul 14, 04:05 UTC | 20h 50m |
| 2026-07-13 | HYT9157 | - | Jul 13, 02:55 UTC | Jul 13, 05:55 UTC | 3h 0m |
| 2026-07-12 | HYT9157 | - | Jul 12, 09:50 UTC | Jul 13, 05:55 UTC | 20h 5m |
| 2026-07-12 | HYT9157 | - | Jul 12, 08:25 UTC | Jul 13, 05:55 UTC | 21h 30m |
| 2026-07-12 | HYT9068 | - | Jul 12, 06:35 UTC | Jul 13, 05:45 UTC | 23h 10m |
| 2026-07-12 | HYT9068 | - | Jul 12, 00:35 UTC | Jul 12, 10:20 UTC | 9h 45m |
| 2026-07-11 | HYT9068 | - | Jul 11, 11:50 UTC | Jul 12, 10:20 UTC | 22h 30m |
| 2026-07-11 | HYT9104 | - | Jul 11, 09:50 UTC | Jul 12, 09:45 UTC | 23h 55m |
| 2026-07-11 | HYT9103 | - | Jul 11, 05:10 UTC | Jul 11, 05:35 UTC | 25m |
| 2026-07-11 | HYT9103 | - | Jul 11, 02:15 UTC | Jul 11, 04:01 UTC | 1h 45m |
| 2026-07-09 | HYT9104 | - | Jul 9, 09:25 UTC | Jul 9, 11:25 UTC | 2h 0m |
| 2026-07-09 | HYT9104 | - | Jul 9, 07:55 UTC | Jul 9, 08:05 UTC | 10m |
| 2026-07-09 | HYT9103 | - | Jul 9, 05:55 UTC | Jul 9, 06:10 UTC | 15m |
| 2026-07-09 | HYT9103 | - | Jul 9, 03:00 UTC | Jul 9, 04:40 UTC | 1h 40m |
| 2026-07-07 | HYT9068 | - | Jul 7, 07:55 UTC | Jul 8, 02:25 UTC | 18h 30m |
| 2026-07-07 | HYT9103 | - | Jul 7, 05:05 UTC | Jul 7, 05:40 UTC | 35m |
| 2026-07-07 | HYT9103 | - | Jul 7, 02:10 UTC | Jul 7, 03:55 UTC | 1h 45m |
| 2026-07-06 | HYT9103 | - | Jul 6, 07:50 UTC | Jul 7, 03:55 UTC | 20h 5m |
| 2026-07-06 | HYT9103 | - | Jul 6, 07:20 UTC | Jul 7, 03:55 UTC | 20h 35m |
| 2026-07-06 | HYT9129 | - | Jul 6, 01:45 UTC | Jul 6, 08:45 UTC | 7h 0m |
| 2026-07-05 | HYT9130 | - | Jul 5, 07:55 UTC | Jul 6, 07:45 UTC | 23h 50m |
| 2026-07-05 | HYT9129 | - | Jul 5, 01:50 UTC | Jul 6, 01:45 UTC | 23h 55m |
| 2026-07-04 | HYT9129 | - | Jul 4, 11:50 UTC | Jul 5, 09:40 UTC | 21h 50m |
| 2026-07-04 | HYT9104 | - | Jul 4, 10:25 UTC | Jul 5, 09:40 UTC | 23h 15m |
| 2026-07-04 | HYT9104 | - | Jul 4, 08:50 UTC | Jul 5, 03:35 UTC | 18h 45m |
| 2026-07-04 | HYT9103 | - | Jul 4, 05:40 UTC | Jul 4, 06:05 UTC | 25m |
| 2026-07-03 | HYT9104 | - | Jul 3, 09:50 UTC | Jul 4, 04:20 UTC | 18h 30m |
| 2026-07-03 | HYT9104 | - | Jul 3, 08:10 UTC | Jul 4, 04:20 UTC | 20h 10m |
| 2026-07-03 | HYT9103 | - | Jul 3, 05:25 UTC | Jul 3, 05:40 UTC | 15m |
| 2026-07-02 | HYT9103 | - | Jul 2, 14:10 UTC | Jul 3, 04:10 UTC | 14h 0m |
| 2026-07-01 | HYT9075 | - | Jul 1, 06:05 UTC | Jul 1, 09:15 UTC | 3h 10m |
| 2026-06-30 | HYT9076 | - | Jun 30, 08:15 UTC | Jun 30, 10:30 UTC | 2h 15m |
| 2026-06-30 | HYT9083 | - | Jun 30, 04:30 UTC | Jun 30, 05:50 UTC | 1h 20m |
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-221A page for operator, model, and routing details .