sensors Mode-S transponder
781B2B
ICAO 24-bit transponder address · allocated to China
Currently assigned to B-125X · SUNWARD Aurora S60/70
- Hex
- 781B2B
- Octal
- 36015453
- Decimal
- 7,871,275
- Country
- CN
- Tail
- B-125X
- Type
- AURA
- Flights observed
- 99
- Distinct callsigns
- 17
- Country
- CN
- Last broadcast
- 4h ago
Last known position
Country allocation
The ICAO 24-bit address 781B2B 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 17 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| HLF9859 | - | 14 | 2026-05-14 |
| HLF9860 | - | 13 | 2026-05-14 |
| HLF8821 | - | 9 | 2026-05-29 |
| HLF9872 | - | 8 | 2026-05-05 |
| HLF9838 | - | 8 | 2026-05-12 |
| HLF9837 | - | 8 | 2026-05-12 |
| HLF9839 | - | 6 | 2026-05-08 |
| HLF8822 | Hapagfly | 6 | 2026-05-30 |
| HLF9840 | - | 5 | 2026-05-08 |
| HLF9817 | - | 5 | 2026-05-24 |
| HLF9801 | - | 5 | 2026-06-01 |
| HLF9802 | - | 4 | 2026-06-02 |
| HLF9871 | - | 2 | 2026-04-28 |
| HLF9818 | Hapagfly | 2 | 2026-05-22 |
| HLF9813 | Hapagfly | 2 | 2026-05-16 |
| HLF9814 | Hapagfly | 1 | 2026-05-16 |
| HLF9808 | - | 1 | 2026-05-18 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-06-02 | HLF9802 | - | Jun 2, 09:00 UTC | Jun 2, 15:15 UTC | 6h 15m |
| 2026-06-01 | HLF9801 | - | Jun 1, 21:55 UTC | Jun 2, 05:25 UTC | 7h 30m |
| 2026-05-31 | HLF9802 | - | May 31, 09:20 UTC | May 31, 15:50 UTC | 6h 30m |
| 2026-05-30 | HLF9801 | - | May 30, 04:50 UTC | May 30, 23:30 UTC | 18h 40m |
| 2026-05-30 | HLF8822 | XCR → SZX | May 30, 02:50 UTC | May 30, 23:30 UTC | 20h 40m |
| 2026-05-30 | HLF8822 | XCR → SZX | May 30, 02:30 UTC | May 30, 23:30 UTC | 21h 0m |
| 2026-05-29 | HLF8821 | - | May 29, 16:05 UTC | May 29, 16:55 UTC | 50m |
| 2026-05-28 | HLF8821 | - | May 28, 18:30 UTC | May 29, 16:45 UTC | 22h 15m |
| 2026-05-28 | HLF9802 | - | May 28, 12:15 UTC | May 28, 19:00 UTC | 6h 45m |
| 2026-05-28 | HLF9801 | - | May 28, 07:50 UTC | May 28, 08:15 UTC | 25m |
| 2026-05-27 | HLF8822 | XCR → SZX | May 27, 07:50 UTC | May 28, 02:45 UTC | 18h 55m |
| 2026-05-26 | HLF8821 | - | May 26, 21:20 UTC | May 26, 22:09 UTC | 50m |
| 2026-05-25 | HLF9802 | - | May 25, 12:20 UTC | May 25, 18:25 UTC | 6h 5m |
| 2026-05-24 | HLF9801 | - | May 24, 16:20 UTC | May 25, 08:35 UTC | 16h 15m |
| 2026-05-24 | HLF9801 | - | May 24, 10:50 UTC | May 25, 08:35 UTC | 21h 45m |
| 2026-05-24 | HLF9817 | - | May 24, 04:10 UTC | May 25, 02:30 UTC | 22h 20m |
| 2026-05-24 | HLF9817 | - | May 24, 01:30 UTC | May 24, 16:30 UTC | 15h 0m |
| 2026-05-23 | HLF9817 | - | May 23, 15:05 UTC | May 24, 10:55 UTC | 19h 50m |
| 2026-05-23 | HLF9817 | - | May 23, 13:25 UTC | May 24, 10:55 UTC | 21h 30m |
| 2026-05-23 | HLF8822 | XCR → SZX | May 23, 09:20 UTC | May 24, 04:45 UTC | 19h 26m |
| 2026-05-23 | HLF8821 | - | May 23, 00:00 UTC | May 23, 06:35 UTC | 6h 34m |
| 2026-05-22 | HLF8821 | - | May 22, 09:20 UTC | May 23, 06:35 UTC | 21h 15m |
| 2026-05-22 | HLF9818 | CDG → CDG | May 22, 07:10 UTC | May 23, 06:35 UTC | 23h 24m |
| 2026-05-22 | HLF9818 | CDG → CDG | May 22, 04:40 UTC | May 23, 00:45 UTC | 20h 5m |
| 2026-05-20 | HLF9817 | - | May 20, 08:50 UTC | May 21, 03:40 UTC | 18h 50m |
| 2026-05-20 | HLF8822 | XCR → SZX | May 20, 07:40 UTC | May 21, 03:40 UTC | 20h 0m |
| 2026-05-19 | HLF8821 | - | May 19, 21:20 UTC | May 20, 04:05 UTC | 6h 45m |
| 2026-05-18 | HLF9808 | - | May 18, 15:20 UTC | May 18, 21:55 UTC | 6h 34m |
| 2026-05-17 | HLF8822 | XCR → SZX | May 17, 11:35 UTC | May 18, 06:25 UTC | 18h 50m |
| 2026-05-17 | HLF8821 | - | May 17, 01:25 UTC | May 17, 08:10 UTC | 6h 45m |
| 2026-05-16 | HLF8821 | - | May 16, 12:11 UTC | May 17, 08:10 UTC | 20h 0m |
| 2026-05-16 | HLF8821 | - | May 16, 08:51 UTC | May 17, 08:10 UTC | 23h 20m |
| 2026-05-16 | HLF9814 | CDG → CDG | May 16, 07:01 UTC | May 17, 06:45 UTC | 23h 44m |
| 2026-05-16 | HLF9813 | CPH → CDG | May 16, 04:00 UTC | May 16, 04:20 UTC | 20m |
| 2026-05-15 | HLF9813 | CPH → CDG | May 15, 22:10 UTC | May 15, 22:55 UTC | 45m |
| 2026-05-14 | HLF9860 | - | May 14, 07:30 UTC | May 14, 09:30 UTC | 2h 0m |
| 2026-05-14 | HLF9859 | - | May 14, 00:40 UTC | May 14, 05:05 UTC | 4h 25m |
| 2026-05-12 | HLF9838 | - | May 12, 18:50 UTC | May 12, 20:50 UTC | 2h 0m |
| 2026-05-12 | HLF9837 | - | May 12, 10:25 UTC | May 12, 16:35 UTC | 6h 10m |
| 2026-05-11 | HLF9837 | - | May 11, 18:50 UTC | May 12, 16:35 UTC | 21h 45m |
| 2026-05-11 | HLF9838 | PRG → PRG | May 11, 18:25 UTC | May 12, 16:35 UTC | 22h 10m |
| 2026-05-11 | HLF9837 | - | May 11, 00:40 UTC | May 11, 02:00 UTC | 1h 20m |
| 2026-05-08 | HLF9840 | - | May 8, 14:40 UTC | May 8, 18:30 UTC | 3h 50m |
| 2026-05-08 | HLF9840 | - | May 8, 12:04 UTC | May 8, 14:35 UTC | 2h 30m |
| 2026-05-08 | HLF9839 | - | May 8, 01:19 UTC | May 8, 08:55 UTC | 7h 35m |
| 2026-05-07 | HLF9839 | - | May 7, 08:50 UTC | May 8, 08:44 UTC | 23h 55m |
| 2026-05-07 | HLF9860 | - | May 7, 07:30 UTC | May 8, 06:45 UTC | 23h 15m |
| 2026-05-07 | HLF9859 | - | May 7, 04:55 UTC | May 7, 05:10 UTC | 15m |
| 2026-05-07 | HLF9859 | - | May 7, 00:35 UTC | May 7, 00:50 UTC | 15m |
| 2026-05-05 | HLF9872 | - | May 5, 06:45 UTC | May 5, 08:00 UTC | 1h 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-125X page for operator, model, and routing details .