sensors Mode-S transponder
781C48
ICAO 24-bit transponder address · allocated to China
Currently assigned to B-221G · BOEING 737-800
- Hex
- 781C48
- Octal
- 36016110
- Decimal
- 7,871,560
- Country
- CN
- Tail
- B-221G
- Type
- B738
- Flights observed
- 40
- Distinct callsigns
- 15
- Country
- CN
- Last broadcast
- 14h ago
Last known position
Country allocation
The ICAO 24-bit address 781C48 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 15 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| RLH6587 | - | 8 | 2026-07-13 |
| RLH6588 | - | 6 | 2026-07-12 |
| RLH6531 | - | 6 | 2026-07-16 |
| RLH6548 | - | 3 | 2026-07-01 |
| RLH6547 | - | 3 | 2026-06-28 |
| RLH6538 | Ruili Airlines | 2 | 2026-07-17 |
| RLH5016 | Ruili Airlines | 2 | 2026-04-18 |
| RLH6554 | Ruili Airlines | 1 | 2026-06-15 |
| RLH6553 | Ruili Airlines | 1 | 2026-06-15 |
| RLH6549 | - | 1 | 2026-06-13 |
| RLH6537 | Ruili Airlines | 1 | 2026-05-22 |
| RLH5011 | Ruili Airlines | 1 | 2026-05-02 |
| RLH5009 | - | 1 | 2026-06-30 |
| RLH5004 | Ruili Airlines | 1 | 2026-05-12 |
| RLH5003 | Ruili Airlines | 1 | 2026-05-12 |
Recent flights last 40
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-17 | RLH6538 | YNT → KMG | Jul 17, 10:05 UTC | Jul 18, 05:20 UTC | 19h 16m |
| 2026-07-16 | RLH6531 | - | Jul 16, 05:15 UTC | Jul 16, 05:30 UTC | 15m |
| 2026-07-13 | RLH6587 | - | Jul 13, 08:55 UTC | Jul 13, 09:05 UTC | 10m |
| 2026-07-12 | RLH6588 | - | Jul 12, 05:05 UTC | Jul 12, 05:15 UTC | 10m |
| 2026-07-11 | RLH6588 | - | Jul 11, 06:45 UTC | Jul 12, 05:15 UTC | 22h 30m |
| 2026-07-08 | RLH6587 | - | Jul 8, 09:15 UTC | Jul 8, 09:25 UTC | 10m |
| 2026-07-03 | RLH6587 | - | Jul 3, 08:50 UTC | Jul 3, 09:00 UTC | 10m |
| 2026-07-01 | RLH6548 | - | Jul 1, 05:35 UTC | Jul 1, 09:10 UTC | 3h 35m |
| 2026-06-30 | RLH5009 | - | Jun 30, 05:20 UTC | Jun 30, 05:35 UTC | 15m |
| 2026-06-29 | RLH6587 | - | Jun 29, 08:44 UTC | Jun 29, 08:54 UTC | 10m |
| 2026-06-28 | RLH6547 | - | Jun 28, 05:20 UTC | Jun 28, 05:40 UTC | 20m |
| 2026-06-26 | RLH6587 | SHE → WUT | Jun 26, 08:45 UTC | Jun 26, 08:54 UTC | 10m |
| 2026-06-24 | RLH6587 | SHE → WUT | Jun 24, 08:55 UTC | Jun 24, 09:09 UTC | 15m |
| 2026-06-24 | RLH6588 | WUT → SHE | Jun 24, 05:20 UTC | Jun 24, 05:34 UTC | 15m |
| 2026-06-22 | RLH6531 | NNY → HRB | Jun 22, 09:04 UTC | Jun 23, 05:15 UTC | 20h 10m |
| 2026-06-22 | RLH6547 | - | Jun 22, 05:24 UTC | Jun 22, 09:14 UTC | 3h 50m |
| 2026-06-21 | RLH6547 | - | Jun 21, 09:10 UTC | Jun 22, 05:40 UTC | 20h 30m |
| 2026-06-21 | RLH6548 | - | Jun 21, 05:04 UTC | Jun 21, 09:20 UTC | 4h 15m |
| 2026-06-15 | RLH6554 | BAR → KMG | Jun 15, 15:50 UTC | Jun 15, 16:04 UTC | 15m |
| 2026-06-15 | RLH6553 | KMG → BAR | Jun 15, 13:54 UTC | Jun 15, 14:05 UTC | 10m |
| 2026-06-13 | RLH6549 | - | Jun 13, 06:15 UTC | Jun 14, 00:55 UTC | 18h 40m |
| 2026-06-10 | RLH6548 | - | Jun 10, 09:45 UTC | Jun 10, 09:55 UTC | 10m |
| 2026-06-06 | RLH6588 | WUT → SHE | Jun 6, 11:14 UTC | Jun 7, 05:20 UTC | 18h 5m |
| 2026-06-04 | RLH6531 | NNY → HRB | Jun 4, 07:45 UTC | Jun 4, 07:55 UTC | 10m |
| 2026-06-02 | RLH6588 | WUT → SHE | Jun 2, 13:50 UTC | Jun 3, 05:30 UTC | 15h 40m |
| 2026-06-02 | RLH6588 | WUT → SHE | Jun 2, 06:15 UTC | Jun 3, 05:30 UTC | 23h 15m |
| 2026-05-29 | RLH6531 | NNY → HRB | May 29, 10:40 UTC | May 30, 05:35 UTC | 18h 55m |
| 2026-05-28 | - | - | May 28, 06:50 UTC | May 28, 10:20 UTC | 3h 30m |
| 2026-05-27 | RLH6587 | SHE → WUT | May 27, 09:10 UTC | May 27, 09:20 UTC | 10m |
| 2026-05-24 | RLH6538 | YNT → KMG | May 24, 09:50 UTC | May 25, 04:45 UTC | 18h 55m |
| 2026-05-22 | RLH6537 | YNT → CGQ | May 22, 04:50 UTC | May 22, 05:05 UTC | 15m |
| 2026-05-12 | RLH5004 | SZX → WUX | May 12, 10:40 UTC | May 12, 10:50 UTC | 10m |
| 2026-05-12 | RLH5003 | WUX → SZX | May 12, 09:00 UTC | May 12, 09:15 UTC | 15m |
| 2026-05-02 | RLH5011 | BAV → TSN | May 2, 03:05 UTC | May 2, 03:30 UTC | 25m |
| 2026-04-30 | - | - | Apr 30, 06:25 UTC | Apr 30, 10:25 UTC | 4h 0m |
| 2026-04-23 | RLH6531 | NNY → HRB | Apr 23, 05:15 UTC | Apr 23, 05:30 UTC | 15m |
| 2026-04-22 | RLH6531 | NNY → HRB | Apr 22, 09:50 UTC | Apr 23, 05:30 UTC | 19h 40m |
| 2026-04-19 | RLH6587 | SHE → WUT | Apr 19, 08:45 UTC | Apr 19, 08:55 UTC | 10m |
| 2026-04-18 | RLH5016 | TFU → WUX | Apr 18, 11:00 UTC | Apr 19, 05:25 UTC | 18h 25m |
| 2026-04-18 | RLH5016 | TFU → WUX | Apr 18, 07:20 UTC | Apr 19, 05:25 UTC | 22h 5m |
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-221G page for operator, model, and routing details .