sensors Mode-S transponder
78121F
ICAO 24-bit transponder address · allocated to China
Currently assigned to B-1313 · BOEING 737-800
- Hex
- 78121F
- Octal
- 36011037
- Decimal
- 7,868,959
- Country
- CN
- Tail
- B-1313
- Type
- B738
- Flights observed
- 53
- Distinct callsigns
- 20
- Country
- CN
- Last broadcast
- 3d ago
Last known position
Country allocation
The ICAO 24-bit address 78121F 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 |
|---|---|---|---|
| YZR7526 | Yangtze River Express | 6 | 2026-05-24 |
| YZR7525 | Yangtze River Express | 6 | 2026-05-23 |
| YZR7579 | Yangtze River Express | 5 | 2026-05-11 |
| YZR7537 | Yangtze River Express | 5 | 2026-05-10 |
| YZR7563 | Yangtze River Express | 4 | 2026-05-20 |
| YZR7577 | Yangtze River Express | 3 | 2026-04-19 |
| YZR7573 | Yangtze River Express | 3 | 2026-05-13 |
| YZR7570 | - | 2 | 2026-05-19 |
| YZR7569 | Yangtze River Express | 2 | 2026-05-19 |
| YZR7566 | Yangtze River Express | 2 | 2026-05-08 |
| YZR7533 | Yangtze River Express | 2 | 2026-04-29 |
| YZR7595 | Yangtze River Express | 1 | 2026-04-19 |
| YZR7591 | Yangtze River Express | 1 | 2026-05-19 |
| YZR7587 | Yangtze River Express | 1 | 2026-05-05 |
| YZR7580 | Yangtze River Express | 1 | 2026-05-10 |
| YZR7575 | Yangtze River Express | 1 | 2026-04-23 |
| YZR7574 | Yangtze River Express | 1 | 2026-05-13 |
| YZR7565 | Yangtze River Express | 1 | 2026-04-13 |
| YZR7564 | - | 1 | 2026-04-17 |
| YZR7538 | Yangtze River Express | 1 | 2026-05-10 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-26 | YZR7532 | HGH → SZX | May 26, 16:10 UTC | May 26, 16:40 UTC | 30m |
| 2026-05-26 | YZR7531 | SZX → HGH | May 26, 01:10 UTC | May 26, 10:20 UTC | 9h 10m |
| 2026-05-24 | YZR7526 | TNA → SZX | May 24, 18:00 UTC | May 24, 18:20 UTC | 20m |
| 2026-05-23 | YZR7525 | SZX → TNA | May 23, 22:25 UTC | May 23, 22:35 UTC | 10m |
| 2026-05-20 | YZR7563 | SZX → LNL | May 20, 04:20 UTC | May 20, 04:30 UTC | 10m |
| 2026-05-19 | YZR7591 | SZX → ACX | May 19, 22:40 UTC | May 19, 22:55 UTC | 15m |
| 2026-05-19 | YZR7570 | - | May 19, 16:40 UTC | May 19, 17:05 UTC | 25m |
| 2026-05-19 | YZR7569 | SZX → CGO | May 19, 01:35 UTC | May 19, 01:45 UTC | 10m |
| 2026-05-18 | YZR7526 | TNA → SZX | May 18, 17:05 UTC | May 18, 17:20 UTC | 15m |
| 2026-05-17 | YZR7525 | SZX → TNA | May 17, 22:25 UTC | May 17, 22:40 UTC | 15m |
| 2026-05-17 | YZR7526 | TNA → SZX | May 17, 17:35 UTC | May 17, 17:45 UTC | 10m |
| 2026-05-16 | YZR7525 | SZX → TNA | May 16, 22:30 UTC | May 16, 22:40 UTC | 10m |
| 2026-05-15 | YZR7528 | HET → SZX | May 15, 16:30 UTC | May 15, 16:45 UTC | 15m |
| 2026-05-14 | YZR7527 | SZX → HET | May 14, 23:05 UTC | May 14, 23:20 UTC | 15m |
| 2026-05-13 | YZR7525 | SZX → TNA | May 13, 22:25 UTC | May 13, 22:35 UTC | 10m |
| 2026-05-13 | YZR7574 | DYG → SZX | May 13, 14:40 UTC | May 13, 14:55 UTC | 15m |
| 2026-05-13 | YZR7573 | SZX → DYG | May 13, 08:45 UTC | May 13, 08:55 UTC | 10m |
| 2026-05-11 | YZR7579 | PVG → ZUH | May 11, 05:55 UTC | May 11, 09:00 UTC | 3h 5m |
| 2026-05-10 | YZR7537 | SZX → KWE | May 10, 22:55 UTC | May 10, 23:05 UTC | 10m |
| 2026-05-10 | YZR7538 | KWE → SZX | May 10, 16:59 UTC | May 10, 17:10 UTC | 10m |
| 2026-05-10 | YZR7580 | ZUH → PVG | May 10, 10:00 UTC | May 10, 10:10 UTC | 10m |
| 2026-05-10 | YZR7579 | PVG → ZUH | May 10, 06:04 UTC | May 10, 06:30 UTC | 25m |
| 2026-05-09 | YZR7537 | SZX → KWE | May 9, 22:55 UTC | May 9, 23:05 UTC | 10m |
| 2026-05-09 | YZR7579 | PVG → ZUH | May 9, 06:05 UTC | May 9, 09:05 UTC | 3h 0m |
| 2026-05-08 | YZR7537 | SZX → KWE | May 8, 23:10 UTC | May 8, 23:20 UTC | 10m |
| 2026-05-08 | YZR7573 | SZX → DYG | May 8, 09:44 UTC | May 8, 09:54 UTC | 10m |
| 2026-05-08 | YZR7566 | PVG → SZX | May 8, 07:29 UTC | May 8, 07:39 UTC | 10m |
| 2026-05-05 | YZR7587 | ZUH → TYN | May 5, 17:40 UTC | May 5, 17:50 UTC | 10m |
| 2026-05-05 | YZR7579 | PVG → ZUH | May 5, 06:10 UTC | May 5, 09:15 UTC | 3h 5m |
| 2026-05-04 | YZR7537 | SZX → KWE | May 4, 23:05 UTC | May 4, 23:20 UTC | 15m |
| 2026-05-04 | YZR7579 | PVG → ZUH | May 4, 06:00 UTC | May 4, 06:25 UTC | 25m |
| 2026-05-03 | YZR7537 | SZX → KWE | May 3, 23:00 UTC | May 3, 23:10 UTC | 10m |
| 2026-05-03 | YZR7526 | TNA → SZX | May 3, 19:10 UTC | May 3, 19:25 UTC | 15m |
| 2026-05-02 | YZR7525 | SZX → TNA | May 2, 22:15 UTC | May 2, 22:25 UTC | 10m |
| 2026-05-02 | YZR7526 | TNA → SZX | May 2, 17:45 UTC | May 2, 17:55 UTC | 10m |
| 2026-05-01 | YZR7525 | SZX → TNA | May 1, 22:20 UTC | May 1, 22:30 UTC | 10m |
| 2026-05-01 | YZR7573 | SZX → DYG | May 1, 08:50 UTC | May 1, 09:00 UTC | 10m |
| 2026-05-01 | YZR7566 | PVG → SZX | May 1, 07:15 UTC | May 1, 07:25 UTC | 10m |
| 2026-04-29 | YZR7533 | XIY → CGQ | Apr 29, 06:10 UTC | Apr 29, 06:29 UTC | 20m |
| 2026-04-26 | YZR7533 | XIY → CGQ | Apr 26, 06:30 UTC | Apr 26, 06:40 UTC | 10m |
| 2026-04-23 | YZR7575 | HGH → SYX | Apr 23, 03:15 UTC | Apr 23, 07:40 UTC | 4h 25m |
| 2026-04-21 | YZR7526 | TNA → SZX | Apr 21, 17:10 UTC | Apr 21, 17:25 UTC | 15m |
| 2026-04-20 | YZR7563 | SZX → LNL | Apr 20, 03:10 UTC | Apr 20, 03:20 UTC | 10m |
| 2026-04-19 | YZR7577 | PVG → SZX | Apr 19, 14:40 UTC | Apr 20, 01:15 UTC | 10h 35m |
| 2026-04-19 | YZR7595 | PVG → HAK | Apr 19, 03:40 UTC | Apr 19, 11:55 UTC | 8h 15m |
| 2026-04-18 | YZR7570 | - | Apr 18, 16:30 UTC | Apr 18, 16:40 UTC | 10m |
| 2026-04-17 | YZR7569 | SZX → CGO | Apr 17, 23:55 UTC | Apr 18, 00:05 UTC | 10m |
| 2026-04-17 | YZR7564 | - | Apr 17, 20:25 UTC | Apr 17, 20:35 UTC | 10m |
| 2026-04-17 | YZR7563 | SZX → LNL | Apr 17, 03:30 UTC | Apr 17, 03:45 UTC | 15m |
| 2026-04-17 | YZR7577 | PVG → SZX | Apr 17, 01:00 UTC | Apr 17, 01:15 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-1313 page for operator, model, and routing details .