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
- 206
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- Jul 26, 20:15 UTC
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 | - | 6 | 2026-07-15 |
| UAL181 | United Airlines | 6 | 2026-07-26 |
| UAL969 | United Airlines | 5 | 2026-07-17 |
| UAL152 | United Airlines | 5 | 2026-06-12 |
| UAL1011 | United Airlines | 5 | 2026-07-20 |
| UAL968 | United Airlines | 4 | 2026-07-17 |
| UAL923 | - | 4 | 2026-06-15 |
| UAL893 | - | 4 | 2026-07-15 |
| UAL892 | - | 4 | 2026-07-16 |
| UAL33 | United Airlines | 4 | 2026-06-09 |
| UAL29 | - | 4 | 2026-06-30 |
| UAL28 | - | 4 | 2026-06-30 |
| UAL263 | United Airlines | 4 | 2026-04-17 |
| UAL2023 | United Airlines | 4 | 2026-07-21 |
| UAL143 | United Airlines | 4 | 2026-06-05 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-26 | UAL181 | FRA → DEN | Jul 26, 10:25 UTC | Jul 26, 20:10 UTC | 9h 45m |
| 2026-07-25 | UAL182 | DEN → FRA | Jul 25, 22:35 UTC | Jul 26, 07:15 UTC | 8h 41m |
| 2026-07-25 | UAL142 | NRT → DEN | Jul 25, 07:55 UTC | Jul 25, 08:30 UTC | 35m |
| 2026-07-25 | UAL142 | NRT → DEN | Jul 25, 07:50 UTC | Jul 25, 18:03 UTC | 10h 13m |
| 2026-07-24 | UAL7 | IAH → NRT | Jul 24, 15:55 UTC | Jul 25, 04:15 UTC | 12h 20m |
| 2026-07-24 | UAL3925 | EWR → SFO | Jul 24, 02:45 UTC | Jul 24, 05:35 UTC | 2h 50m |
| 2026-07-22 | UAL353 | SAN → EWR | Jul 22, 23:15 UTC | Jul 23, 04:10 UTC | 4h 55m |
| 2026-07-22 | UAL3040 | IAD → EWR | Jul 22, 19:25 UTC | Jul 22, 20:10 UTC | 45m |
| 2026-07-21 | UAL2023 | BOS → ORD | Jul 21, 18:21 UTC | Jul 22, 09:08 UTC | 14h 47m |
| 2026-07-21 | UAL2023 | BOS → ORD | Jul 21, 18:05 UTC | Jul 21, 18:25 UTC | 20m |
| 2026-07-20 | UAL1011 | MCI → SFO | Jul 20, 23:00 UTC | Jul 20, 23:50 UTC | 50m |
| 2026-07-20 | UAL1011 | MCI → SFO | Jul 20, 23:01 UTC | Jul 21, 12:50 UTC | 13h 49m |
| 2026-07-19 | UAL2023 | BOS → ORD | Jul 19, 18:20 UTC | Jul 20, 09:20 UTC | 15h 0m |
| 2026-07-19 | UAL2023 | BOS → ORD | Jul 19, 18:21 UTC | Jul 20, 09:20 UTC | 14h 59m |
| 2026-07-19 | UAL1011 | MCI → SFO | Jul 19, 15:05 UTC | Jul 19, 15:20 UTC | 15m |
| 2026-07-19 | UAL1011 | MCI → SFO | Jul 19, 01:30 UTC | Jul 19, 02:25 UTC | 55m |
| 2026-07-19 | UAL1011 | MCI → SFO | Jul 19, 00:56 UTC | Jul 19, 15:11 UTC | 14h 15m |
| 2026-07-18 | UAL1849 | MCO → EWR | Jul 18, 15:44 UTC | Jul 18, 21:08 UTC | 5h 24m |
| 2026-07-18 | UAL1849 | MCO → EWR | Jul 18, 15:50 UTC | Jul 18, 21:05 UTC | 5h 15m |
| 2026-07-17 | UAL969 | AMS → SFO | Jul 17, 13:16 UTC | Jul 17, 23:39 UTC | 10h 23m |
| 2026-07-17 | UAL969 | AMS → SFO | Jul 17, 13:20 UTC | Jul 17, 21:00 UTC | 7h 40m |
| 2026-07-17 | UAL968 | SFO → AMS | Jul 17, 00:14 UTC | Jul 17, 09:40 UTC | 9h 25m |
| 2026-07-16 | UAL892 | - | Jul 16, 07:55 UTC | Jul 16, 18:25 UTC | 10h 30m |
| 2026-07-15 | UAL893 | SFO → ICN | Jul 15, 18:35 UTC | Jul 16, 05:55 UTC | 11h 20m |
| 2026-07-15 | UAL806 | ICN → SFO | Jul 15, 02:55 UTC | Jul 15, 13:30 UTC | 10h 35m |
| 2026-07-14 | UAL805 | SFO → ICN | Jul 14, 08:10 UTC | Jul 14, 19:15 UTC | 11h 5m |
| 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 |
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 .