sensors Mode-S transponder
78021B
ICAO 24-bit transponder address · allocated to China
Currently assigned to B-LIE · BOEING 747-400
- Hex
- 78021B
- Octal
- 36001033
- Decimal
- 7,864,859
- Country
- CN
- Tail
- B-LIE
- Type
- B744
- Flights observed
- 21
- Distinct callsigns
- 12
- Country
- CN
- Last broadcast
- Jul 23, 01:10 UTC
Current position
Country allocation
The ICAO 24-bit address 78021B 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 12 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| CPA3280 | - | 3 | 2026-07-16 |
| CPA068 | Cathay Pacific | 3 | 2026-07-19 |
| CPA3281 | Cathay Pacific | 2 | 2026-07-17 |
| CPA3069 | - | 2 | 2026-07-21 |
| CPA3046 | Cathay Pacific | 2 | 2026-07-18 |
| CPA098 | Cathay Pacific | 2 | 2026-07-20 |
| CPA017 | Cathay Pacific | 2 | 2026-07-22 |
| CPA3261 | Cathay Pacific | 1 | 2026-07-22 |
| CPA3260 | Cathay Pacific | 1 | 2026-07-21 |
| CPA3147 | Cathay Pacific | 1 | 2026-07-17 |
| CPA3018 | Cathay Pacific | 1 | 2026-07-23 |
| CPA067 | Cathay Pacific | 1 | 2026-07-18 |
Recent flights last 21
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-23 | CPA3018 | MAA → HKG | Jul 23, 01:00 UTC | Jul 23, 01:05 UTC | 5m |
| 2026-07-22 | CPA017 | MAA → CMB | Jul 22, 14:15 UTC | Jul 22, 23:20 UTC | 9h 5m |
| 2026-07-22 | CPA017 | MAA → CMB | Jul 22, 13:30 UTC | Jul 22, 13:45 UTC | 15m |
| 2026-07-22 | CPA3261 | CKG → CTU | Jul 22, 01:25 UTC | Jul 22, 01:50 UTC | 25m |
| 2026-07-21 | CPA3260 | HKG → CKG | Jul 21, 19:45 UTC | Jul 21, 20:05 UTC | 20m |
| 2026-07-21 | CPA3069 | ANC → HKG | Jul 21, 06:45 UTC | Jul 21, 17:10 UTC | 10h 25m |
| 2026-07-20 | CPA3069 | - | Jul 20, 23:25 UTC | Jul 21, 05:20 UTC | 5h 54m |
| 2026-07-20 | CPA098 | ANC → HKG | Jul 20, 14:50 UTC | Jul 20, 20:10 UTC | 5h 20m |
| 2026-07-20 | CPA098 | ANC → HKG | Jul 20, 03:40 UTC | Jul 20, 13:10 UTC | 9h 30m |
| 2026-07-19 | CPA068 | MXP → HKG | Jul 19, 22:35 UTC | Jul 19, 23:00 UTC | 25m |
| 2026-07-19 | CPA068 | MXP → HKG | Jul 19, 12:00 UTC | Jul 19, 14:00 UTC | 2h 0m |
| 2026-07-19 | CPA068 | MXP → HKG | Jul 19, 08:20 UTC | Jul 19, 09:10 UTC | 50m |
| 2026-07-18 | CPA067 | HKG → MAA | Jul 18, 13:00 UTC | Jul 19, 05:40 UTC | 16h 40m |
| 2026-07-18 | CPA3046 | HAN → HKG | Jul 18, 04:30 UTC | Jul 18, 05:10 UTC | 40m |
| 2026-07-18 | CPA3046 | HAN → HKG | Jul 18, 03:35 UTC | Jul 18, 03:45 UTC | 10m |
| 2026-07-17 | CPA3147 | HKG → HAN | Jul 17, 23:30 UTC | Jul 17, 23:39 UTC | 10m |
| 2026-07-17 | CPA3281 | LAX → PDX | Jul 17, 08:20 UTC | Jul 17, 17:55 UTC | 9h 35m |
| 2026-07-17 | CPA3281 | LAX → PDX | Jul 17, 01:49 UTC | Jul 17, 04:59 UTC | 3h 10m |
| 2026-07-16 | CPA3280 | - | Jul 16, 22:10 UTC | Jul 16, 23:55 UTC | 1h 45m |
| 2026-07-16 | CPA3280 | - | Jul 16, 14:35 UTC | Jul 16, 19:25 UTC | 4h 50m |
| 2026-07-16 | CPA3280 | HKG → ANC | Jul 16, 03:10 UTC | Jul 16, 12:55 UTC | 9h 45m |
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-LIE page for operator, model, and routing details .