sensors Mode-S transponder
AD4521
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N954SP · BOMBARDIER BD-700 Global 6000/6500 · operated by TVPX AIRCRAFT SOLUTIONS INC TRUSTEE
- Hex
- AD4521
- Octal
- 53242441
- Decimal
- 11,355,425
- Country
- US
- Tail
- N954SP
- Type
- GLEX
- Flights observed
- 64
- Distinct callsigns
- 1
- Country
- US
- Last broadcast
- 18h ago
Last known position
Country allocation
The ICAO 24-bit address AD4521 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 |
|---|---|---|---|
| N954SP | - | 64 | 2026-07-21 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-21 | N954SP | - | Jul 21, 01:00 UTC | Jul 21, 01:25 UTC | 25m |
| 2026-07-20 | N954SP | - | Jul 20, 18:10 UTC | Jul 20, 20:45 UTC | 2h 35m |
| 2026-07-17 | N954SP | - | Jul 17, 22:49 UTC | Jul 17, 23:25 UTC | 35m |
| 2026-07-17 | N954SP | - | Jul 17, 18:55 UTC | Jul 17, 19:05 UTC | 10m |
| 2026-07-10 | N954SP | - | Jul 10, 22:35 UTC | Jul 10, 22:40 UTC | 5m |
| 2026-07-10 | N954SP | - | Jul 10, 17:30 UTC | Jul 10, 18:05 UTC | 35m |
| 2026-07-07 | N954SP | - | Jul 7, 16:15 UTC | Jul 7, 21:20 UTC | 5h 5m |
| 2026-07-05 | N954SP | - | Jul 5, 21:55 UTC | Jul 5, 22:05 UTC | 10m |
| 2026-07-05 | N954SP | - | Jul 5, 20:40 UTC | Jul 5, 21:25 UTC | 45m |
| 2026-07-04 | N954SP | - | Jul 4, 00:40 UTC | Jul 4, 03:05 UTC | 2h 25m |
| 2026-07-02 | N954SP | - | Jul 2, 22:30 UTC | Jul 3, 01:00 UTC | 2h 30m |
| 2026-07-02 | N954SP | VNY → PVD | Jul 2, 16:10 UTC | Jul 2, 20:55 UTC | 4h 45m |
| 2026-07-01 | N954SP | - | Jul 1, 17:05 UTC | Jul 1, 23:45 UTC | 6h 40m |
| 2026-06-30 | N954SP | - | Jun 30, 18:25 UTC | Jun 30, 18:40 UTC | 15m |
| 2026-06-30 | N954SP | - | Jun 30, 12:20 UTC | Jun 30, 17:00 UTC | 4h 40m |
| 2026-06-21 | N954SP | - | Jun 21, 13:00 UTC | Jun 21, 17:50 UTC | 4h 50m |
| 2026-06-21 | N954SP | - | Jun 21, 10:54 UTC | Jun 21, 12:19 UTC | 1h 25m |
| 2026-06-20 | N954SP | - | Jun 20, 14:59 UTC | Jun 20, 18:10 UTC | 3h 10m |
| 2026-06-18 | N954SP | - | Jun 18, 22:15 UTC | Jun 19, 01:34 UTC | 3h 19m |
| 2026-06-17 | N954SP | VNY → SUS | Jun 17, 17:55 UTC | Jun 17, 20:50 UTC | 2h 55m |
| 2026-06-16 | N954SP | - | Jun 16, 06:59 UTC | Jun 16, 07:09 UTC | 10m |
| 2026-06-15 | N954SP | - | Jun 15, 22:49 UTC | Jun 16, 06:20 UTC | 7h 30m |
| 2026-06-15 | N954SP | - | Jun 15, 21:04 UTC | Jun 15, 21:30 UTC | 25m |
| 2026-06-10 | N954SP | - | Jun 10, 14:55 UTC | Jun 10, 22:20 UTC | 7h 25m |
| 2026-06-03 | N954SP | - | Jun 3, 19:05 UTC | Jun 4, 00:25 UTC | 5h 20m |
| 2026-06-03 | N954SP | - | Jun 3, 14:10 UTC | Jun 3, 16:25 UTC | 2h 15m |
| 2026-06-01 | N954SP | - | Jun 1, 21:00 UTC | Jun 1, 21:30 UTC | 30m |
| 2026-06-01 | N954SP | - | Jun 1, 15:00 UTC | Jun 1, 18:20 UTC | 3h 20m |
| 2026-06-01 | N954SP | - | Jun 1, 00:55 UTC | Jun 1, 01:10 UTC | 15m |
| 2026-05-29 | N954SP | - | May 29, 23:30 UTC | May 30, 00:05 UTC | 35m |
| 2026-05-23 | N954SP | - | May 23, 17:10 UTC | May 23, 17:45 UTC | 35m |
| 2026-05-21 | N954SP | TEB → VNY | May 21, 05:05 UTC | May 21, 10:45 UTC | 5h 40m |
| 2026-05-20 | N954SP | OAK → TEB | May 20, 12:10 UTC | May 20, 16:40 UTC | 4h 30m |
| 2026-05-19 | N954SP | VNY → OAK | May 19, 21:35 UTC | May 19, 22:30 UTC | 55m |
| 2026-05-15 | N954SP | - | May 15, 14:35 UTC | May 15, 18:15 UTC | 3h 39m |
| 2026-05-13 | N954SP | VNY → BNA | May 13, 16:30 UTC | May 13, 19:55 UTC | 3h 25m |
| 2026-05-06 | N954SP | - | May 6, 16:00 UTC | May 6, 21:05 UTC | 5h 4m |
| 2026-05-05 | N954SP | - | May 5, 19:05 UTC | May 5, 20:45 UTC | 1h 40m |
| 2026-05-05 | N954SP | - | May 5, 15:35 UTC | May 5, 18:35 UTC | 3h 0m |
| 2026-05-05 | N954SP | - | May 5, 14:05 UTC | May 5, 14:40 UTC | 35m |
| 2026-05-03 | N954SP | - | May 3, 15:30 UTC | May 3, 18:30 UTC | 3h 0m |
| 2026-05-03 | N954SP | - | May 3, 13:30 UTC | May 3, 14:55 UTC | 1h 25m |
| 2026-04-30 | N954SP | - | Apr 30, 19:35 UTC | Apr 30, 20:55 UTC | 1h 20m |
| 2026-04-30 | N954SP | - | Apr 30, 16:35 UTC | Apr 30, 19:00 UTC | 2h 25m |
| 2026-04-28 | N954SP | - | Apr 28, 02:10 UTC | Apr 28, 02:30 UTC | 20m |
| 2026-04-28 | N954SP | - | Apr 28, 00:30 UTC | Apr 28, 01:15 UTC | 45m |
| 2026-04-27 | N954SP | - | Apr 27, 04:30 UTC | Apr 27, 07:00 UTC | 2h 30m |
| 2026-04-27 | N954SP | - | Apr 27, 00:40 UTC | Apr 27, 03:55 UTC | 3h 15m |
| 2026-04-24 | N954SP | - | Apr 24, 16:10 UTC | Apr 24, 18:40 UTC | 2h 30m |
| 2026-04-24 | N954SP | - | Apr 24, 14:50 UTC | Apr 24, 15:40 UTC | 50m |
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 N954SP page for operator, model, and routing details .