sensors Mode-S transponder
8991FF
ICAO 24-bit transponder address · allocated to Taiwan
Currently assigned to B-00101 · BEECHCRAFT Super King Air 350
- Hex
- 8991FF
- Octal
- 42310777
- Decimal
- 9,015,807
- Country
- TW
- Tail
- B-00101
- Type
- B350
- Flights observed
- 29
- Distinct callsigns
- 1
- Country
- TW
- Last broadcast
- 2d ago
Last known position
Country allocation
The ICAO 24-bit address 8991FF falls within the block assigned to Taiwan (TW) by ICAO Annex 10, Volume III. Every aircraft registered in Taiwan 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 1 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| FC101 | - | 29 | 2026-05-28 |
Recent flights last 29
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-28 | FC101 | - | May 28, 06:10 UTC | May 28, 07:25 UTC | 1h 15m |
| 2026-05-28 | FC101 | TSA → KHH | May 28, 01:40 UTC | May 28, 03:30 UTC | 1h 50m |
| 2026-05-27 | FC101 | - | May 27, 00:59 UTC | May 27, 02:24 UTC | 1h 25m |
| 2026-05-25 | FC101 | - | May 25, 01:55 UTC | May 25, 02:45 UTC | 50m |
| 2026-05-21 | FC101 | TSA → TSA | May 21, 01:00 UTC | May 21, 01:55 UTC | 55m |
| 2026-05-20 | FC101 | - | May 20, 01:05 UTC | May 20, 02:00 UTC | 55m |
| 2026-05-18 | FC101 | - | May 18, 06:20 UTC | May 18, 06:55 UTC | 35m |
| 2026-05-18 | FC101 | - | May 18, 01:35 UTC | May 18, 01:55 UTC | 20m |
| 2026-05-14 | FC101 | - | May 14, 06:00 UTC | May 14, 07:20 UTC | 1h 20m |
| 2026-05-14 | FC101 | - | May 14, 01:50 UTC | May 14, 04:10 UTC | 2h 20m |
| 2026-05-12 | FC101 | - | May 12, 06:05 UTC | May 12, 06:25 UTC | 20m |
| 2026-05-07 | FC101 | - | May 7, 05:45 UTC | May 7, 06:35 UTC | 50m |
| 2026-05-07 | FC101 | - | May 7, 02:00 UTC | May 7, 04:00 UTC | 2h 0m |
| 2026-05-06 | FC101 | - | May 6, 01:05 UTC | May 6, 02:40 UTC | 1h 35m |
| 2026-04-29 | FC101 | - | Apr 29, 05:45 UTC | Apr 29, 06:15 UTC | 30m |
| 2026-04-29 | FC101 | - | Apr 29, 01:45 UTC | Apr 29, 03:15 UTC | 1h 30m |
| 2026-04-28 | FC101 | - | Apr 28, 06:20 UTC | Apr 28, 06:40 UTC | 20m |
| 2026-04-28 | FC101 | - | Apr 28, 01:40 UTC | Apr 28, 02:00 UTC | 20m |
| 2026-04-22 | FC101 | - | Apr 22, 02:50 UTC | Apr 22, 03:00 UTC | 10m |
| 2026-04-22 | FC101 | - | Apr 22, 01:40 UTC | Apr 22, 01:55 UTC | 15m |
| 2026-04-21 | FC101 | - | Apr 21, 06:15 UTC | Apr 21, 06:30 UTC | 15m |
| 2026-04-21 | FC101 | - | Apr 21, 01:45 UTC | Apr 21, 02:05 UTC | 20m |
| 2026-04-16 | FC101 | - | Apr 16, 05:45 UTC | Apr 16, 06:29 UTC | 45m |
| 2026-04-16 | FC101 | - | Apr 16, 03:09 UTC | Apr 16, 03:45 UTC | 35m |
| 2026-04-16 | FC101 | - | Apr 16, 02:00 UTC | Apr 16, 03:04 UTC | 1h 5m |
| 2026-04-15 | FC101 | - | Apr 15, 06:00 UTC | Apr 15, 06:55 UTC | 55m |
| 2026-04-15 | FC101 | - | Apr 15, 02:55 UTC | Apr 15, 03:35 UTC | 40m |
| 2026-04-15 | FC101 | - | Apr 15, 01:45 UTC | Apr 15, 02:50 UTC | 1h 5m |
| 2026-04-14 | FC101 | - | Apr 14, 06:20 UTC | Apr 14, 07:00 UTC | 40m |
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-00101 page for operator, model, and routing details .