sensors Mode-S transponder
A31F51
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N300 · CESSNA P337 Skymaster · operated by TEXAS SKY MASTERS INC DBA, TEXAS SKYMASTERS
- Hex
- A31F51
- Octal
- 50617521
- Decimal
- 10,690,385
- Country
- US
- Tail
- N300
- Type
- P337
- Flights observed
- 23
- Distinct callsigns
- 11
- Country
- US
- Last broadcast
- Jun 21, 04:24 UTC
Last known position
Country allocation
The ICAO 24-bit address A31F51 falls within the block assigned to United States (US) by ICAO Annex 10, Volume III. Every aircraft registered in United States 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 23
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-06-21 | SHR17 | XJD → XJD | Jun 21, 03:19 UTC | Jun 21, 04:24 UTC | 1h 5m |
| 2026-06-18 | SHR09 | - | Jun 18, 03:45 UTC | Jun 18, 04:30 UTC | 45m |
| 2026-06-17 | SHR19 | - | Jun 17, 04:20 UTC | Jun 17, 04:35 UTC | 15m |
| 2026-06-15 | SHR12 | - | Jun 15, 06:30 UTC | Jun 15, 07:29 UTC | 1h 0m |
| 2026-06-15 | SHR11 | XJD → XJD | Jun 15, 03:19 UTC | Jun 15, 04:25 UTC | 1h 5m |
| 2026-06-14 | SHR08 | - | Jun 14, 04:10 UTC | Jun 14, 05:10 UTC | 1h 0m |
| 2026-06-09 | SHR08 | - | Jun 9, 06:20 UTC | Jun 9, 07:10 UTC | 50m |
| 2026-06-09 | SHR14 | XJD → XJD | Jun 9, 03:35 UTC | Jun 9, 04:25 UTC | 50m |
| 2026-06-04 | SHR07 | - | Jun 4, 05:35 UTC | Jun 4, 06:30 UTC | 55m |
| 2026-06-04 | SHR11 | - | Jun 4, 03:35 UTC | Jun 4, 04:35 UTC | 1h 0m |
| 2026-06-03 | SHR12 | - | Jun 3, 06:40 UTC | Jun 3, 07:25 UTC | 45m |
| 2026-06-03 | SHR20 | - | Jun 3, 03:45 UTC | Jun 3, 04:15 UTC | 30m |
| 2026-06-01 | SHR09 | XJD → XJD | Jun 1, 08:40 UTC | Jun 1, 09:30 UTC | 50m |
| 2026-06-01 | SHR16 | - | Jun 1, 04:25 UTC | Jun 1, 05:00 UTC | 35m |
| 2026-05-19 | SHR11 | - | May 19, 03:40 UTC | May 19, 04:35 UTC | 55m |
| 2026-05-18 | SHR19 | - | May 18, 03:55 UTC | May 18, 04:55 UTC | 1h 0m |
| 2026-05-17 | SHR15 | - | May 17, 03:35 UTC | May 17, 04:40 UTC | 1h 5m |
| 2026-05-12 | SHR09 | XJD → XJD | May 12, 06:35 UTC | May 12, 07:30 UTC | 55m |
| 2026-05-12 | SHR08 | XJD → XJD | May 12, 03:20 UTC | May 12, 04:20 UTC | 1h 0m |
| 2026-05-05 | SHR11 | - | May 5, 06:15 UTC | May 5, 07:10 UTC | 55m |
| 2026-05-04 | SHR08 | - | May 4, 06:25 UTC | May 4, 07:15 UTC | 50m |
| 2026-05-04 | SHR11 | - | May 4, 03:09 UTC | May 4, 04:15 UTC | 1h 5m |
| 2026-04-26 | SHR19 | - | Apr 26, 06:10 UTC | Apr 26, 06:55 UTC | 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 N300 page for operator, model, and routing details .