sensors Mode-S transponder
A559A3
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N444BS · CESSNA T210 Turbo Centurion · operated by SIEMENS CHRISTOPHER L, SIEMENS JOHN W
- Hex
- A559A3
- Octal
- 51254643
- Decimal
- 10,836,387
- Country
- US
- Tail
- N444BS
- Type
- T210
- Flights observed
- 58
- Distinct callsigns
- 1
- Country
- US
- Last broadcast
- 15d ago
Last known position
Country allocation
The ICAO 24-bit address A559A3 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 1 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| N444BS | - | 58 | 2026-07-20 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-20 | N444BS | - | Jul 20, 23:45 UTC | Jul 21, 00:30 UTC | 45m |
| 2026-07-20 | N444BS | - | Jul 20, 14:50 UTC | Jul 20, 15:30 UTC | 40m |
| 2026-07-13 | N444BS | - | Jul 13, 21:10 UTC | Jul 13, 21:50 UTC | 40m |
| 2026-07-13 | N444BS | - | Jul 13, 13:45 UTC | Jul 13, 14:30 UTC | 45m |
| 2026-07-12 | N444BS | - | Jul 12, 18:20 UTC | Jul 12, 19:01 UTC | 40m |
| 2026-07-12 | N444BS | - | Jul 12, 14:25 UTC | Jul 12, 15:15 UTC | 50m |
| 2026-07-09 | N444BS | - | Jul 9, 18:50 UTC | Jul 9, 19:20 UTC | 30m |
| 2026-07-09 | N444BS | - | Jul 9, 13:05 UTC | Jul 9, 13:35 UTC | 30m |
| 2026-06-29 | N444BS | - | Jun 29, 15:30 UTC | Jun 29, 16:04 UTC | 35m |
| 2026-06-29 | N444BS | - | Jun 29, 12:39 UTC | Jun 29, 13:19 UTC | 40m |
| 2026-06-28 | N444BS | - | Jun 28, 15:29 UTC | Jun 28, 16:00 UTC | 30m |
| 2026-06-26 | N444BS | - | Jun 26, 13:10 UTC | Jun 26, 13:55 UTC | 45m |
| 2026-06-25 | N444BS | - | Jun 25, 14:44 UTC | Jun 25, 15:10 UTC | 25m |
| 2026-06-25 | N444BS | - | Jun 25, 10:20 UTC | Jun 25, 10:55 UTC | 35m |
| 2026-06-24 | N444BS | - | Jun 24, 15:24 UTC | Jun 24, 15:39 UTC | 15m |
| 2026-06-24 | N444BS | - | Jun 24, 13:24 UTC | Jun 24, 13:50 UTC | 25m |
| 2026-06-18 | N444BS | - | Jun 18, 23:30 UTC | Jun 18, 23:50 UTC | 20m |
| 2026-06-18 | N444BS | - | Jun 18, 10:45 UTC | Jun 18, 11:25 UTC | 40m |
| 2026-06-12 | N444BS | - | Jun 12, 19:40 UTC | Jun 12, 20:05 UTC | 25m |
| 2026-06-12 | N444BS | - | Jun 12, 15:25 UTC | Jun 12, 15:50 UTC | 25m |
| 2026-06-09 | N444BS | - | Jun 9, 17:15 UTC | Jun 9, 18:00 UTC | 45m |
| 2026-06-09 | N444BS | - | Jun 9, 13:10 UTC | Jun 9, 13:55 UTC | 45m |
| 2026-06-08 | N444BS | - | Jun 8, 19:35 UTC | Jun 8, 20:00 UTC | 25m |
| 2026-06-08 | N444BS | - | Jun 8, 16:20 UTC | Jun 8, 16:40 UTC | 20m |
| 2026-06-05 | N444BS | - | Jun 5, 20:15 UTC | Jun 5, 20:45 UTC | 30m |
| 2026-06-05 | N444BS | - | Jun 5, 13:45 UTC | Jun 5, 14:05 UTC | 20m |
| 2026-06-02 | N444BS | - | Jun 2, 21:05 UTC | Jun 2, 21:50 UTC | 45m |
| 2026-06-02 | N444BS | - | Jun 2, 13:25 UTC | Jun 2, 14:10 UTC | 45m |
| 2026-05-29 | N444BS | - | May 29, 16:30 UTC | May 29, 16:55 UTC | 25m |
| 2026-05-29 | N444BS | - | May 29, 14:40 UTC | May 29, 15:05 UTC | 25m |
| 2026-05-28 | N444BS | - | May 28, 19:00 UTC | May 28, 19:45 UTC | 45m |
| 2026-05-22 | N444BS | - | May 22, 21:30 UTC | May 22, 22:10 UTC | 40m |
| 2026-05-22 | N444BS | - | May 22, 15:05 UTC | May 22, 15:50 UTC | 45m |
| 2026-05-19 | N444BS | - | May 19, 19:05 UTC | May 19, 20:10 UTC | 1h 5m |
| 2026-05-19 | N444BS | - | May 19, 12:50 UTC | May 19, 13:15 UTC | 25m |
| 2026-05-13 | N444BS | - | May 13, 22:10 UTC | May 13, 22:30 UTC | 20m |
| 2026-05-13 | N444BS | - | May 13, 14:15 UTC | May 13, 14:40 UTC | 25m |
| 2026-05-12 | N444BS | - | May 12, 23:10 UTC | May 12, 23:55 UTC | 45m |
| 2026-05-12 | N444BS | - | May 12, 15:10 UTC | May 12, 15:55 UTC | 45m |
| 2026-05-11 | N444BS | - | May 11, 20:15 UTC | May 11, 20:35 UTC | 20m |
| 2026-05-11 | N444BS | - | May 11, 14:55 UTC | May 11, 15:20 UTC | 25m |
| 2026-05-07 | N444BS | - | May 7, 22:54 UTC | May 7, 23:34 UTC | 40m |
| 2026-05-07 | N444BS | - | May 7, 15:35 UTC | May 7, 16:15 UTC | 40m |
| 2026-05-06 | N444BS | - | May 6, 22:25 UTC | May 6, 22:45 UTC | 20m |
| 2026-05-06 | N444BS | - | May 6, 18:35 UTC | May 6, 18:55 UTC | 20m |
| 2026-05-05 | N444BS | - | May 5, 21:15 UTC | May 5, 21:40 UTC | 25m |
| 2026-05-05 | N444BS | - | May 5, 12:50 UTC | May 5, 13:30 UTC | 40m |
| 2026-05-04 | N444BS | - | May 4, 17:50 UTC | May 4, 18:15 UTC | 25m |
| 2026-05-04 | N444BS | - | May 4, 14:30 UTC | May 4, 14:50 UTC | 20m |
| 2026-04-30 | N444BS | - | Apr 30, 17:00 UTC | Apr 30, 17:30 UTC | 30m |
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 N444BS page for operator, model, and routing details .