sensors Mode-S transponder
71C566
ICAO 24-bit transponder address · allocated to Korea, South
Currently assigned to 21-001 · BOEING 737 MAX 8
- Hex
- 71C566
- Octal
- 34342546
- Decimal
- 7,456,102
- Country
- KR
- Tail
- 21-001
- Type
- B38M
- Flights observed
- 35
- Distinct callsigns
- 11
- Country
- KR
- Last broadcast
- 14d ago
Last known position
Country allocation
The ICAO 24-bit address 71C566 falls within the block assigned to Korea, South (KR) by ICAO Annex 10, Volume III. Every aircraft registered in Korea, South 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 11 distinct
Recent flights last 35
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-22 | LR73 | SSN → SSN | Jul 22, 00:35 UTC | Jul 22, 01:30 UTC | 55m |
| 2026-07-19 | DC73 | PUS → SSN | Jul 19, 12:05 UTC | Jul 19, 12:40 UTC | 35m |
| 2026-07-19 | DC73 | SSN → PUS | Jul 19, 06:50 UTC | Jul 19, 07:25 UTC | 35m |
| 2026-07-15 | LR73 | SSN → SSN | Jul 15, 01:05 UTC | Jul 15, 02:35 UTC | 1h 30m |
| 2026-07-10 | LR73 | SSN → SSN | Jul 10, 01:00 UTC | Jul 10, 02:50 UTC | 1h 50m |
| 2026-07-03 | EC73 | - | Jul 3, 08:20 UTC | Jul 3, 08:50 UTC | 30m |
| 2026-07-03 | EC73 | - | Jul 3, 03:55 UTC | Jul 3, 04:20 UTC | 25m |
| 2026-07-02 | NE73 | - | Jul 2, 07:05 UTC | Jul 2, 07:45 UTC | 40m |
| 2026-07-02 | NE73 | - | Jul 2, 05:25 UTC | Jul 2, 05:50 UTC | 25m |
| 2026-06-30 | WF73 | - | Jun 30, 09:35 UTC | Jun 30, 10:10 UTC | 35m |
| 2026-06-30 | WF73 | - | Jun 30, 05:10 UTC | Jun 30, 05:25 UTC | 15m |
| 2026-06-26 | NE73 | - | Jun 26, 05:44 UTC | Jun 26, 06:15 UTC | 30m |
| 2026-06-26 | NE73 | - | Jun 26, 02:00 UTC | Jun 26, 02:24 UTC | 25m |
| 2026-06-24 | KAF002 | - | Jun 24, 13:00 UTC | Jun 24, 13:30 UTC | 30m |
| 2026-06-23 | KAF002 | - | Jun 23, 04:00 UTC | Jun 23, 04:09 UTC | 10m |
| 2026-06-22 | KAF002 | - | Jun 22, 06:15 UTC | Jun 22, 06:49 UTC | 35m |
| 2026-06-19 | LR73 | SSN → SSN | Jun 19, 01:45 UTC | Jun 19, 02:45 UTC | 1h 0m |
| 2026-06-08 | LR73 | SSN → SSN | Jun 8, 01:05 UTC | Jun 8, 02:50 UTC | 1h 45m |
| 2026-06-02 | LR73 | - | Jun 2, 02:25 UTC | Jun 2, 02:55 UTC | 30m |
| 2026-06-02 | LR73 | - | Jun 2, 01:15 UTC | Jun 2, 01:45 UTC | 30m |
| 2026-05-27 | MO73 | - | May 27, 06:20 UTC | May 27, 06:49 UTC | 30m |
| 2026-05-26 | IV73 | - | May 26, 04:24 UTC | May 26, 04:50 UTC | 25m |
| 2026-05-23 | WF73 | TRD → OSL | May 23, 08:20 UTC | May 23, 08:50 UTC | 30m |
| 2026-05-23 | WF73 | TRD → OSL | May 23, 02:10 UTC | May 23, 02:35 UTC | 24m |
| 2026-05-19 | SH73 | - | May 19, 12:30 UTC | May 19, 12:55 UTC | 25m |
| 2026-05-17 | HY73 | - | May 17, 23:40 UTC | May 18, 00:00 UTC | 20m |
| 2026-05-13 | CK73 | - | May 13, 10:20 UTC | May 13, 10:45 UTC | 25m |
| 2026-05-13 | CK73 | - | May 13, 04:50 UTC | May 13, 05:15 UTC | 25m |
| 2026-05-11 | NE73 | - | May 11, 03:40 UTC | May 11, 04:20 UTC | 40m |
| 2026-05-11 | NE73 | - | May 11, 00:05 UTC | May 11, 00:30 UTC | 25m |
| 2026-05-07 | LR73 | SSN → SSN | May 7, 05:20 UTC | May 7, 06:15 UTC | 55m |
| 2026-04-29 | LR73 | SSN → SSN | Apr 29, 00:54 UTC | Apr 29, 01:54 UTC | 1h 0m |
| 2026-04-21 | LR73 | - | Apr 21, 01:05 UTC | Apr 21, 01:55 UTC | 50m |
| 2026-04-16 | LR73 | - | Apr 16, 02:09 UTC | Apr 16, 02:24 UTC | 15m |
| 2026-04-16 | LR73 | - | Apr 16, 01:10 UTC | Apr 16, 01:20 UTC | 10m |
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 21-001 page for operator, model, and routing details .