sensors Mode-S transponder
A724BD
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N56BU · GULFSTREAM 5 · operated by BSI HOLDINGS LLC
- Hex
- A724BD
- Octal
- 51622275
- Decimal
- 10,953,917
- Country
- US
- Tail
- N56BU
- Type
- GLF5
- Flights observed
- 47
- Distinct callsigns
- 1
- Country
- US
- Last broadcast
- 14h ago
Last known position
Country allocation
The ICAO 24-bit address A724BD 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 |
|---|---|---|---|
| N56BU | - | 47 | 2026-07-17 |
Recent flights last 47
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-17 | N56BU | - | Jul 17, 16:10 UTC | Jul 17, 18:40 UTC | 2h 30m |
| 2026-07-16 | N56BU | - | Jul 16, 01:35 UTC | Jul 16, 04:40 UTC | 3h 5m |
| 2026-07-15 | N56BU | - | Jul 15, 21:50 UTC | Jul 16, 01:30 UTC | 3h 40m |
| 2026-07-06 | N56BU | - | Jul 6, 14:45 UTC | Jul 6, 17:25 UTC | 2h 40m |
| 2026-07-06 | N56BU | - | Jul 6, 09:35 UTC | Jul 6, 12:45 UTC | 3h 10m |
| 2026-07-05 | N56BU | MSP → TMB | Jul 5, 15:35 UTC | Jul 5, 18:50 UTC | 3h 15m |
| 2026-07-05 | N56BU | - | Jul 5, 14:30 UTC | Jul 5, 15:05 UTC | 35m |
| 2026-07-05 | N56BU | - | Jul 5, 11:15 UTC | Jul 5, 13:50 UTC | 2h 35m |
| 2026-06-26 | N56BU | - | Jun 26, 22:55 UTC | Jun 27, 01:44 UTC | 2h 50m |
| 2026-06-26 | N56BU | - | Jun 26, 19:50 UTC | Jun 26, 22:10 UTC | 2h 20m |
| 2026-06-26 | N56BU | - | Jun 26, 16:20 UTC | Jun 26, 19:14 UTC | 2h 55m |
| 2026-06-26 | N56BU | - | Jun 26, 12:44 UTC | Jun 26, 15:49 UTC | 3h 5m |
| 2026-06-25 | N56BU | ABY → SUA | Jun 25, 21:29 UTC | Jun 25, 22:24 UTC | 55m |
| 2026-06-25 | N56BU | - | Jun 25, 18:45 UTC | Jun 25, 20:45 UTC | 2h 0m |
| 2026-06-20 | N56BU | - | Jun 20, 23:19 UTC | Jun 21, 01:35 UTC | 2h 15m |
| 2026-06-20 | N56BU | - | Jun 20, 15:39 UTC | Jun 20, 21:44 UTC | 6h 5m |
| 2026-06-13 | N56BU | - | Jun 13, 14:30 UTC | Jun 13, 14:50 UTC | 20m |
| 2026-06-13 | N56BU | - | Jun 13, 12:40 UTC | Jun 13, 13:05 UTC | 25m |
| 2026-06-11 | N56BU | - | Jun 11, 16:20 UTC | Jun 11, 20:05 UTC | 3h 45m |
| 2026-06-09 | N56BU | - | Jun 9, 22:00 UTC | Jun 10, 01:45 UTC | 3h 45m |
| 2026-06-09 | N56BU | - | Jun 9, 19:35 UTC | Jun 9, 21:10 UTC | 1h 35m |
| 2026-06-06 | N56BU | - | Jun 6, 22:00 UTC | Jun 6, 23:44 UTC | 1h 45m |
| 2026-06-03 | N56BU | - | Jun 3, 17:55 UTC | Jun 3, 19:40 UTC | 1h 45m |
| 2026-06-03 | N56BU | - | Jun 3, 15:55 UTC | Jun 3, 16:50 UTC | 55m |
| 2026-05-30 | N56BU | - | May 30, 16:20 UTC | May 30, 16:55 UTC | 35m |
| 2026-05-29 | N56BU | - | May 29, 03:20 UTC | May 29, 08:05 UTC | 4h 45m |
| 2026-05-28 | N56BU | - | May 28, 17:50 UTC | May 29, 02:35 UTC | 8h 45m |
| 2026-05-28 | N56BU | - | May 28, 15:20 UTC | May 28, 15:35 UTC | 15m |
| 2026-05-24 | N56BU | - | May 24, 02:55 UTC | May 24, 10:50 UTC | 7h 55m |
| 2026-05-24 | N56BU | - | May 24, 00:45 UTC | May 24, 01:45 UTC | 1h 0m |
| 2026-05-23 | N56BU | - | May 23, 23:10 UTC | May 24, 00:10 UTC | 1h 0m |
| 2026-05-23 | N56BU | - | May 23, 15:50 UTC | May 23, 19:30 UTC | 3h 40m |
| 2026-05-17 | N56BU | - | May 17, 21:50 UTC | May 18, 02:20 UTC | 4h 30m |
| 2026-05-17 | N56BU | - | May 17, 16:20 UTC | May 17, 20:50 UTC | 4h 30m |
| 2026-05-15 | N56BU | - | May 15, 15:55 UTC | May 15, 18:50 UTC | 2h 55m |
| 2026-05-14 | N56BU | - | May 14, 16:00 UTC | May 14, 17:50 UTC | 1h 50m |
| 2026-05-12 | N56BU | - | May 12, 18:25 UTC | May 12, 21:55 UTC | 3h 30m |
| 2026-05-05 | N56BU | - | May 5, 18:35 UTC | May 5, 21:05 UTC | 2h 30m |
| 2026-05-04 | N56BU | - | May 4, 16:50 UTC | May 4, 22:05 UTC | 5h 16m |
| 2026-05-04 | N56BU | - | May 4, 00:55 UTC | May 4, 04:09 UTC | 3h 15m |
| 2026-05-03 | N56BU | - | May 3, 19:20 UTC | May 3, 21:35 UTC | 2h 15m |
| 2026-05-01 | N56BU | - | May 1, 15:15 UTC | May 1, 18:55 UTC | 3h 40m |
| 2026-04-29 | N56BU | - | Apr 29, 17:50 UTC | Apr 29, 18:50 UTC | 1h 0m |
| 2026-04-27 | N56BU | - | Apr 27, 19:35 UTC | Apr 27, 22:05 UTC | 2h 30m |
| 2026-04-23 | N56BU | - | Apr 23, 15:50 UTC | Apr 23, 18:15 UTC | 2h 24m |
| 2026-04-16 | N56BU | - | Apr 16, 19:15 UTC | Apr 16, 21:00 UTC | 1h 45m |
| 2026-04-16 | N56BU | - | Apr 16, 18:15 UTC | Apr 16, 19:10 UTC | 55m |
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 N56BU page for operator, model, and routing details .