sensors Mode-S transponder
AE54EF
ICAO 24-bit transponder address
Currently assigned to 166221 · Raytheon T-6B Texan II
- Hex
- AE54EF
- Octal
- 53452357
- Decimal
- 11,425,007
- Tail
- 166221
- Type
- TEX2
- Flights observed
- 20
- Distinct callsigns
- 4
- Country
- -
- Last broadcast
- 1d ago
Last known position
Callsign history 4 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| RN221 | - | 9 | 2026-05-28 |
| SH221 | - | 6 | 2026-05-27 |
| BB221 | - | 3 | 2026-05-29 |
| MX221 | Breeze Airways | 2 | 2026-05-18 |
Recent flights last 20
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-29 | BB221 | - | May 29, 13:00 UTC | May 29, 13:35 UTC | 35m |
| 2026-05-28 | RN221 | - | May 28, 17:25 UTC | May 28, 18:00 UTC | 35m |
| 2026-05-28 | RN221 | - | May 28, 14:20 UTC | May 28, 14:50 UTC | 30m |
| 2026-05-27 | SH221 | - | May 27, 13:45 UTC | May 27, 14:10 UTC | 25m |
| 2026-05-27 | SH221 | - | May 27, 00:44 UTC | May 27, 00:55 UTC | 10m |
| 2026-05-26 | RN221 | - | May 26, 14:40 UTC | May 26, 15:09 UTC | 30m |
| 2026-05-21 | RN221 | - | May 21, 17:20 UTC | May 21, 18:20 UTC | 1h 0m |
| 2026-05-21 | RN221 | - | May 21, 14:30 UTC | May 21, 15:30 UTC | 1h 0m |
| 2026-05-21 | RN221 | - | May 21, 00:05 UTC | May 21, 01:15 UTC | 1h 10m |
| 2026-05-20 | RN221 | - | May 20, 21:10 UTC | May 20, 21:25 UTC | 15m |
| 2026-05-20 | RN221 | - | May 20, 20:20 UTC | May 20, 20:40 UTC | 20m |
| 2026-05-20 | RN221 | - | May 20, 13:30 UTC | May 20, 14:35 UTC | 1h 5m |
| 2026-05-20 | SH221 | - | May 20, 01:15 UTC | May 20, 03:00 UTC | 1h 45m |
| 2026-05-19 | SH221 | - | May 19, 22:20 UTC | May 19, 23:30 UTC | 1h 10m |
| 2026-05-19 | SH221 | - | May 19, 17:05 UTC | May 19, 18:30 UTC | 1h 25m |
| 2026-05-19 | SH221 | - | May 19, 13:45 UTC | May 19, 14:45 UTC | 1h 0m |
| 2026-05-19 | BB221 | - | May 19, 00:55 UTC | May 19, 02:00 UTC | 1h 5m |
| 2026-05-18 | BB221 | - | May 18, 21:50 UTC | May 18, 22:40 UTC | 50m |
| 2026-05-18 | MX221 | PVD → CHS | May 18, 15:55 UTC | May 18, 16:05 UTC | 10m |
| 2026-05-15 | MX221 | PVD → CHS | May 15, 13:00 UTC | May 15, 13:35 UTC | 35m |
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 166221 page for operator, model, and routing details .