sensors Mode-S transponder
459904
ICAO 24-bit transponder address · allocated to Denmark
Currently assigned to OY-FHD · DE HAVILLAND DHC-6 Twin Otter
- Hex
- 459904
- Octal
- 21314404
- Decimal
- 4,561,156
- Country
- DK
- Tail
- OY-FHD
- Type
- DHC6
- Flights observed
- 76
- Distinct callsigns
- 4
- Country
- DK
- Last broadcast
- Jul 26, 14:25 UTC
Last known position
Country allocation
The ICAO 24-bit address 459904 falls within the block assigned to Denmark (DK) by ICAO Annex 10, Volume III. Every aircraft registered in Denmark 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 4 distinct
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-26 | FHV22 | - | Jul 26, 13:50 UTC | Jul 26, 14:25 UTC | 35m |
| 2026-07-26 | FHV22 | - | Jul 26, 12:55 UTC | Jul 26, 13:15 UTC | 20m |
| 2026-07-26 | FHV22 | - | Jul 26, 08:05 UTC | Jul 26, 09:50 UTC | 1h 45m |
| 2026-07-25 | FHV22 | - | Jul 25, 12:50 UTC | Jul 25, 14:35 UTC | 1h 45m |
| 2026-07-23 | FHV22 | - | Jul 23, 12:35 UTC | Jul 23, 14:20 UTC | 1h 45m |
| 2026-07-20 | FHV22 | - | Jul 20, 08:40 UTC | Jul 20, 10:50 UTC | 2h 10m |
| 2026-07-19 | FHV22 | - | Jul 19, 13:50 UTC | Jul 19, 14:50 UTC | 1h 0m |
| 2026-07-19 | FHV22 | - | Jul 19, 10:40 UTC | Jul 19, 12:05 UTC | 1h 25m |
| 2026-07-19 | FHV22 | - | Jul 19, 09:15 UTC | Jul 19, 09:45 UTC | 30m |
| 2026-07-18 | FHV22 | - | Jul 18, 07:45 UTC | Jul 18, 08:30 UTC | 45m |
| 2026-07-17 | FHV22 | - | Jul 17, 11:35 UTC | Jul 17, 13:15 UTC | 1h 40m |
| 2026-07-17 | FHV22 | - | Jul 17, 07:55 UTC | Jul 17, 09:25 UTC | 1h 30m |
| 2026-07-16 | FHV22 | - | Jul 16, 13:54 UTC | Jul 16, 16:35 UTC | 2h 40m |
| 2026-07-13 | FHV22 | - | Jul 13, 12:30 UTC | Jul 13, 14:35 UTC | 2h 5m |
| 2026-07-12 | FHV22 | RKE → RKE | Jul 12, 12:01 UTC | Jul 12, 14:10 UTC | 2h 10m |
| 2026-07-12 | FHV22 | RKE → RKE | Jul 12, 07:31 UTC | Jul 12, 09:15 UTC | 1h 45m |
| 2026-07-09 | FHV22 | - | Jul 9, 08:40 UTC | Jul 9, 10:50 UTC | 2h 10m |
| 2026-07-08 | FHV22 | - | Jul 8, 14:55 UTC | Jul 8, 16:20 UTC | 1h 25m |
| 2026-07-08 | FHV22 | - | Jul 8, 14:00 UTC | Jul 8, 14:15 UTC | 15m |
| 2026-07-01 | FHV22 | - | Jul 1, 08:35 UTC | Jul 1, 08:55 UTC | 20m |
| 2026-06-27 | FHV22 | - | Jun 27, 18:29 UTC | Jun 27, 19:15 UTC | 45m |
| 2026-06-27 | FHV22 | - | Jun 27, 15:10 UTC | Jun 27, 17:49 UTC | 2h 40m |
| 2026-06-27 | FHV22 | - | Jun 27, 13:24 UTC | Jun 27, 14:14 UTC | 50m |
| 2026-06-24 | FHV22 | - | Jun 24, 14:39 UTC | Jun 24, 15:35 UTC | 55m |
| 2026-06-24 | FHV22 | - | Jun 24, 12:30 UTC | Jun 24, 13:44 UTC | 1h 15m |
| 2026-06-23 | FHV22 | - | Jun 23, 10:24 UTC | Jun 23, 10:55 UTC | 30m |
| 2026-06-22 | FHV22 | - | Jun 22, 15:29 UTC | Jun 22, 16:54 UTC | 1h 25m |
| 2026-06-22 | FHV22 | - | Jun 22, 11:50 UTC | Jun 22, 13:25 UTC | 1h 35m |
| 2026-06-21 | FHV22 | - | Jun 21, 11:49 UTC | Jun 21, 13:09 UTC | 1h 20m |
| 2026-06-18 | FHV22 | - | Jun 18, 18:10 UTC | Jun 18, 20:00 UTC | 1h 50m |
| 2026-06-18 | FHV22 | - | Jun 18, 14:30 UTC | Jun 18, 16:40 UTC | 2h 10m |
| 2026-06-18 | FHV22 | - | Jun 18, 10:00 UTC | Jun 18, 12:35 UTC | 2h 35m |
| 2026-06-17 | FHV22 | - | Jun 17, 15:20 UTC | Jun 17, 17:25 UTC | 2h 5m |
| 2026-06-07 | FHV22 | - | Jun 7, 11:25 UTC | Jun 7, 13:20 UTC | 1h 55m |
| 2026-06-02 | FHV22 | - | Jun 2, 19:55 UTC | Jun 2, 22:15 UTC | 2h 20m |
| 2026-05-31 | FHV22 | - | May 31, 08:30 UTC | May 31, 09:35 UTC | 1h 5m |
| 2026-05-25 | FHV22 | - | May 25, 08:25 UTC | May 25, 11:00 UTC | 2h 35m |
| 2026-05-23 | SPDER22 | - | May 23, 12:55 UTC | May 23, 15:35 UTC | 2h 40m |
| 2026-05-23 | SPDR22 | - | May 23, 07:55 UTC | May 23, 11:05 UTC | 3h 10m |
| 2026-05-20 | FHV22 | - | May 20, 13:35 UTC | May 20, 14:40 UTC | 1h 5m |
| 2026-05-20 | FHV22 | - | May 20, 10:40 UTC | May 20, 12:15 UTC | 1h 35m |
| 2026-05-20 | FHV22 | RKE → RKE | May 20, 06:55 UTC | May 20, 08:40 UTC | 1h 45m |
| 2026-05-17 | FHV22 | - | May 17, 14:25 UTC | May 17, 15:45 UTC | 1h 20m |
| 2026-05-17 | FHV22 | - | May 17, 12:30 UTC | May 17, 13:35 UTC | 1h 5m |
| 2026-05-17 | FHV22 | - | May 17, 09:20 UTC | May 17, 11:01 UTC | 1h 40m |
| 2026-05-17 | FHV22 | - | May 17, 06:35 UTC | May 17, 08:00 UTC | 1h 25m |
| 2026-05-10 | OYFHD | - | May 10, 14:30 UTC | May 10, 14:59 UTC | 30m |
| 2026-05-10 | OYFHD | - | May 10, 10:19 UTC | May 10, 11:35 UTC | 1h 15m |
| 2026-05-10 | OYFHD | - | May 10, 05:50 UTC | May 10, 08:50 UTC | 3h 0m |
| 2026-05-09 | OYFHD | - | May 9, 15:10 UTC | May 9, 15:20 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 OY-FHD page for operator, model, and routing details .