sensors Mode-S transponder
A31A54
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N30PX · GULFSTREAM G280 · operated by UNITED AIRLINES INC
- Hex
- A31A54
- Octal
- 50615124
- Decimal
- 10,689,108
- Country
- US
- Tail
- N30PX
- Type
- G280
- Flights observed
- 181
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 4h ago
Last known position
Country allocation
The ICAO 24-bit address A31A54 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 20 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| UAL26 | United Airlines | 13 | 2026-04-23 |
| UAL27 | United Airlines | 9 | 2026-04-23 |
| UAL805 | - | 7 | 2026-07-14 |
| UAL178 | United Airlines | 7 | 2026-04-24 |
| UAL177 | United Airlines | 7 | 2026-04-24 |
| UAL806 | - | 5 | 2026-07-11 |
| UAL181 | United Airlines | 5 | 2026-04-21 |
| UAL152 | United Airlines | 5 | 2026-06-12 |
| UAL923 | - | 4 | 2026-06-15 |
| UAL33 | United Airlines | 4 | 2026-06-09 |
| UAL29 | - | 4 | 2026-06-30 |
| UAL28 | - | 4 | 2026-06-30 |
| UAL263 | United Airlines | 4 | 2026-04-17 |
| UAL143 | United Airlines | 4 | 2026-06-05 |
| UAL99 | United Airlines | 3 | 2026-05-03 |
| UAL969 | - | 3 | 2026-07-13 |
| UAL968 | - | 3 | 2026-07-12 |
| UAL935 | - | 3 | 2026-06-16 |
| UAL893 | - | 3 | 2026-07-11 |
| UAL892 | - | 3 | 2026-07-12 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-14 | UAL805 | - | Jul 14, 08:10 UTC | Jul 14, 08:40 UTC | 30m |
| 2026-07-13 | UAL969 | AMS → SFO | Jul 13, 13:21 UTC | Jul 13, 23:58 UTC | 10h 37m |
| 2026-07-13 | UAL969 | - | Jul 13, 13:25 UTC | Jul 13, 14:50 UTC | 1h 25m |
| 2026-07-12 | UAL968 | SFO → AMS | Jul 12, 22:23 UTC | Jul 13, 07:35 UTC | 9h 12m |
| 2026-07-12 | UAL968 | SFO → AMS | Jul 12, 22:10 UTC | Jul 13, 07:45 UTC | 9h 35m |
| 2026-07-12 | UAL892 | - | Jul 12, 08:10 UTC | Jul 12, 18:40 UTC | 10h 30m |
| 2026-07-11 | UAL893 | SFO → ICN | Jul 11, 18:15 UTC | Jul 12, 05:45 UTC | 11h 30m |
| 2026-07-11 | UAL806 | - | Jul 11, 02:30 UTC | Jul 11, 13:00 UTC | 10h 30m |
| 2026-07-10 | UAL805 | SFO → ICN | Jul 10, 07:44 UTC | Jul 10, 19:24 UTC | 11h 40m |
| 2026-07-10 | UAL805 | SFO → ICN | Jul 10, 07:45 UTC | Jul 10, 19:30 UTC | 11h 45m |
| 2026-07-09 | UAL8227 | EWR → SFO | Jul 9, 17:50 UTC | Jul 9, 23:30 UTC | 5h 40m |
| 2026-07-08 | UAL187 | - | Jul 8, 20:10 UTC | Jul 9, 11:10 UTC | 15h 0m |
| 2026-07-08 | UAL188 | EWR → JNB | Jul 8, 03:25 UTC | Jul 8, 17:35 UTC | 14h 10m |
| 2026-07-07 | UAL713 | SFO → EWR | Jul 7, 17:50 UTC | Jul 7, 22:51 UTC | 5h 1m |
| 2026-07-07 | UAL713 | SFO → EWR | Jul 7, 18:20 UTC | Jul 7, 22:55 UTC | 4h 35m |
| 2026-07-07 | UAL114 | - | Jul 7, 07:30 UTC | Jul 7, 08:05 UTC | 35m |
| 2026-07-07 | UAL114 | PPT → SFO | Jul 7, 07:30 UTC | Jul 7, 15:04 UTC | 7h 34m |
| 2026-07-07 | UAL114 | PPT → SFO | Jul 7, 07:30 UTC | Jul 7, 15:11 UTC | 7h 41m |
| 2026-07-06 | UAL115 | - | Jul 6, 20:50 UTC | Jul 7, 04:45 UTC | 7h 55m |
| 2026-07-05 | UAL949 | - | Jul 5, 12:25 UTC | Jul 5, 22:55 UTC | 10h 30m |
| 2026-07-05 | UAL948 | SFO → LHR | Jul 5, 00:14 UTC | Jul 5, 09:55 UTC | 9h 41m |
| 2026-07-05 | UAL948 | - | Jul 5, 00:15 UTC | Jul 5, 03:25 UTC | 3h 10m |
| 2026-07-04 | UAL806 | ICN → SFO | Jul 4, 02:56 UTC | Jul 4, 12:49 UTC | 9h 53m |
| 2026-07-04 | UAL806 | - | Jul 4, 02:50 UTC | Jul 4, 04:40 UTC | 1h 50m |
| 2026-07-03 | UAL805 | SFO → ICN | Jul 3, 07:55 UTC | Jul 3, 19:50 UTC | 11h 55m |
| 2026-07-02 | UAL806 | - | Jul 2, 02:45 UTC | Jul 2, 12:30 UTC | 9h 45m |
| 2026-07-01 | UAL805 | SFO → ICN | Jul 1, 07:26 UTC | Jul 1, 19:07 UTC | 11h 41m |
| 2026-07-01 | UAL805 | - | Jul 1, 07:15 UTC | Jul 1, 17:00 UTC | 9h 45m |
| 2026-06-30 | UAL28 | - | Jun 30, 16:15 UTC | Jun 30, 16:45 UTC | 30m |
| 2026-06-30 | UAL28 | SIN → SFO | Jun 30, 13:21 UTC | Jul 1, 04:30 UTC | 15h 9m |
| 2026-06-30 | UAL29 | - | Jun 30, 10:15 UTC | Jun 30, 10:25 UTC | 10m |
| 2026-06-29 | UAL29 | - | Jun 29, 18:44 UTC | Jun 30, 08:50 UTC | 14h 6m |
| 2026-06-29 | UAL806 | ICN → SFO | Jun 29, 02:39 UTC | Jun 29, 12:49 UTC | 10h 10m |
| 2026-06-28 | UAL805 | SFO → ICN | Jun 28, 07:14 UTC | Jun 28, 18:49 UTC | 11h 35m |
| 2026-06-27 | UAL969 | - | Jun 27, 13:30 UTC | Jun 27, 23:39 UTC | 10h 10m |
| 2026-06-26 | UAL968 | SFO → AMS | Jun 26, 22:19 UTC | Jun 27, 08:10 UTC | 9h 50m |
| 2026-06-26 | UAL892 | ICN → SFO | Jun 26, 08:16 UTC | Jun 26, 18:03 UTC | 9h 47m |
| 2026-06-26 | UAL892 | - | Jun 26, 08:10 UTC | Jun 26, 09:55 UTC | 1h 45m |
| 2026-06-25 | UAL893 | SFO → ICN | Jun 25, 18:20 UTC | Jun 26, 06:02 UTC | 11h 42m |
| 2026-06-25 | UAL893 | SFO → ICN | Jun 25, 18:29 UTC | Jun 26, 06:09 UTC | 11h 40m |
| 2026-06-25 | UAL61 | - | Jun 25, 01:24 UTC | Jun 25, 02:59 UTC | 1h 35m |
| 2026-06-25 | UAL61 | MEL → SFO | Jun 25, 01:09 UTC | Jun 25, 14:59 UTC | 13h 50m |
| 2026-06-24 | UAL60 | SFO → MEL | Jun 24, 07:05 UTC | Jun 24, 22:35 UTC | 15h 30m |
| 2026-06-23 | UAL1757 | - | Jun 23, 22:25 UTC | Jun 24, 03:24 UTC | 5h 0m |
| 2026-06-23 | UAL1849 | MCO → EWR | Jun 23, 15:30 UTC | Jun 23, 20:04 UTC | 4h 35m |
| 2026-06-21 | UAL1227 | EWR → SFO | Jun 21, 20:50 UTC | Jun 22, 02:00 UTC | 5h 10m |
| 2026-06-21 | UAL123 | - | Jun 21, 07:00 UTC | Jun 21, 13:39 UTC | 6h 40m |
| 2026-06-20 | UAL122 | - | Jun 20, 13:49 UTC | Jun 20, 19:55 UTC | 6h 5m |
| 2026-06-19 | UAL83 | DEL → EWR | Jun 19, 18:30 UTC | Jun 19, 23:00 UTC | 4h 30m |
| 2026-06-19 | UAL83 | DEL → EWR | Jun 19, 18:32 UTC | Jun 20, 09:52 UTC | 15h 20m |
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 N30PX page for operator, model, and routing details .