sensors Mode-S transponder
A51A71
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N428MG · CESSNA 525A Citation CJ2 · operated by SEIS PRIMOS INVESTMENTS LLC
- Hex
- A51A71
- Octal
- 51215161
- Decimal
- 10,820,209
- Country
- US
- Tail
- N428MG
- Type
- C25A
- Flights observed
- 60
- Distinct callsigns
- 1
- Country
- US
- Last broadcast
- 18h ago
Last known position
Country allocation
The ICAO 24-bit address A51A71 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 |
|---|---|---|---|
| N428MG | - | 60 | 2026-07-17 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-17 | N428MG | - | Jul 17, 19:40 UTC | Jul 17, 21:30 UTC | 1h 50m |
| 2026-07-17 | N428MG | - | Jul 17, 13:35 UTC | Jul 17, 14:15 UTC | 40m |
| 2026-07-17 | N428MG | - | Jul 17, 11:55 UTC | Jul 17, 12:35 UTC | 40m |
| 2026-07-16 | N428MG | - | Jul 16, 20:29 UTC | Jul 16, 21:55 UTC | 1h 25m |
| 2026-07-16 | N428MG | - | Jul 16, 15:25 UTC | Jul 16, 16:15 UTC | 50m |
| 2026-07-16 | N428MG | - | Jul 16, 13:54 UTC | Jul 16, 14:10 UTC | 15m |
| 2026-07-09 | N428MG | - | Jul 9, 13:45 UTC | Jul 9, 22:10 UTC | 8h 25m |
| 2026-06-26 | N428MG | - | Jun 26, 16:20 UTC | Jun 26, 17:44 UTC | 1h 25m |
| 2026-06-25 | N428MG | - | Jun 25, 18:00 UTC | Jun 25, 19:49 UTC | 1h 50m |
| 2026-06-25 | N428MG | - | Jun 25, 13:40 UTC | Jun 25, 14:39 UTC | 1h 0m |
| 2026-06-24 | N428MG | - | Jun 24, 22:14 UTC | Jun 24, 22:39 UTC | 25m |
| 2026-06-23 | N428MG | - | Jun 23, 17:50 UTC | Jun 23, 18:14 UTC | 25m |
| 2026-06-23 | N428MG | - | Jun 23, 14:55 UTC | Jun 23, 17:15 UTC | 2h 20m |
| 2026-06-23 | N428MG | - | Jun 23, 13:05 UTC | Jun 23, 14:04 UTC | 1h 0m |
| 2026-06-22 | N428MG | - | Jun 22, 12:19 UTC | Jun 22, 14:55 UTC | 2h 35m |
| 2026-06-21 | N428MG | - | Jun 21, 22:04 UTC | Jun 22, 00:20 UTC | 2h 15m |
| 2026-06-19 | N428MG | - | Jun 19, 14:54 UTC | Jun 19, 16:55 UTC | 2h 0m |
| 2026-06-19 | N428MG | - | Jun 19, 12:44 UTC | Jun 19, 13:29 UTC | 45m |
| 2026-06-19 | N428MG | - | Jun 19, 11:45 UTC | Jun 19, 12:09 UTC | 25m |
| 2026-06-19 | N428MG | - | Jun 19, 09:55 UTC | Jun 19, 11:09 UTC | 1h 15m |
| 2026-06-12 | N428MG | - | Jun 12, 22:50 UTC | Jun 12, 23:00 UTC | 10m |
| 2026-06-12 | N428MG | - | Jun 12, 21:00 UTC | Jun 12, 22:10 UTC | 1h 10m |
| 2026-06-12 | N428MG | - | Jun 12, 19:40 UTC | Jun 12, 20:10 UTC | 30m |
| 2026-06-12 | N428MG | - | Jun 12, 13:30 UTC | Jun 12, 14:20 UTC | 50m |
| 2026-06-12 | N428MG | - | Jun 12, 12:50 UTC | Jun 12, 13:00 UTC | 10m |
| 2026-06-07 | N428MG | - | Jun 7, 20:25 UTC | Jun 7, 20:35 UTC | 10m |
| 2026-06-07 | N428MG | - | Jun 7, 19:05 UTC | Jun 7, 19:50 UTC | 45m |
| 2026-06-07 | N428MG | - | Jun 7, 16:15 UTC | Jun 7, 17:00 UTC | 45m |
| 2026-06-07 | N428MG | - | Jun 7, 15:10 UTC | Jun 7, 15:25 UTC | 15m |
| 2026-05-30 | N428MG | - | May 30, 18:45 UTC | May 30, 19:30 UTC | 45m |
| 2026-05-24 | N428MG | - | May 24, 15:55 UTC | May 24, 16:30 UTC | 35m |
| 2026-05-24 | N428MG | - | May 24, 15:05 UTC | May 24, 15:20 UTC | 15m |
| 2026-05-19 | N428MG | ADS → RBD | May 19, 01:25 UTC | May 19, 01:35 UTC | 10m |
| 2026-05-18 | N428MG | - | May 18, 22:20 UTC | May 19, 00:50 UTC | 2h 30m |
| 2026-05-15 | N428MG | - | May 15, 21:15 UTC | May 15, 23:35 UTC | 2h 20m |
| 2026-05-13 | N428MG | - | May 13, 22:35 UTC | May 14, 00:15 UTC | 1h 40m |
| 2026-05-13 | N428MG | - | May 13, 21:20 UTC | May 13, 21:35 UTC | 15m |
| 2026-05-07 | N428MG | - | May 7, 00:35 UTC | May 7, 03:25 UTC | 2h 50m |
| 2026-05-06 | N428MG | - | May 6, 23:30 UTC | May 7, 00:00 UTC | 30m |
| 2026-05-05 | N428MG | - | May 5, 21:01 UTC | May 5, 21:20 UTC | 20m |
| 2026-05-05 | N428MG | - | May 5, 18:45 UTC | May 5, 20:30 UTC | 1h 45m |
| 2026-05-03 | N428MG | - | May 3, 17:29 UTC | May 3, 18:45 UTC | 1h 15m |
| 2026-05-03 | N428MG | - | May 3, 13:45 UTC | May 3, 15:10 UTC | 1h 25m |
| 2026-05-02 | N428MG | - | May 2, 21:55 UTC | May 3, 00:20 UTC | 2h 25m |
| 2026-04-29 | N428MG | - | Apr 29, 21:20 UTC | Apr 29, 21:45 UTC | 25m |
| 2026-04-28 | N428MG | - | Apr 28, 15:20 UTC | Apr 28, 15:50 UTC | 30m |
| 2026-04-28 | N428MG | WRB → FTY | Apr 28, 14:15 UTC | Apr 28, 15:10 UTC | 55m |
| 2026-04-28 | N428MG | - | Apr 28, 11:00 UTC | Apr 28, 13:00 UTC | 2h 0m |
| 2026-04-27 | N428MG | - | Apr 27, 22:35 UTC | Apr 27, 22:50 UTC | 15m |
| 2026-04-27 | N428MG | - | Apr 27, 19:15 UTC | Apr 27, 22:05 UTC | 2h 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 N428MG page for operator, model, and routing details .