sensors Mode-S transponder
A254D7
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N24973 · BOEING 787-9 Dreamliner · operated by UNITED AIRLINES INC
- Hex
- A254D7
- Octal
- 50452327
- Decimal
- 10,638,551
- Country
- US
- Tail
- N24973
- Type
- B789
- Flights observed
- 100
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 1h ago
Last known position
Country allocation
The ICAO 24-bit address A254D7 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 |
|---|---|---|---|
| UAL62 | United Airlines | 7 | 2026-05-30 |
| UAL198 | United Airlines | 7 | 2026-04-18 |
| UAL6 | United Airlines | 6 | 2026-05-29 |
| UAL806 | United Airlines | 5 | 2026-05-23 |
| UAL805 | United Airlines | 5 | 2026-05-22 |
| UAL7 | United Airlines | 5 | 2026-04-17 |
| UAL893 | United Airlines | 4 | 2026-05-08 |
| UAL892 | United Airlines | 4 | 2026-05-09 |
| UAL820 | United Airlines | 4 | 2026-05-27 |
| UAL63 | United Airlines | 4 | 2026-04-16 |
| UAL61 | United Airlines | 4 | 2026-05-11 |
| UAL33 | United Airlines | 4 | 2026-04-17 |
| UAL32 | United Airlines | 4 | 2026-05-29 |
| UAL60 | United Airlines | 3 | 2026-05-10 |
| UAL28 | United Airlines | 3 | 2026-05-22 |
| UAL2023 | United Airlines | 3 | 2026-04-29 |
| UAL1757 | United Airlines | 3 | 2026-05-01 |
| UAL870 | United Airlines | 2 | 2026-04-23 |
| UAL863 | United Airlines | 2 | 2026-04-22 |
| UAL821 | United Airlines | 2 | 2026-05-27 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-30 | UAL62 | IAH → GRU | May 30, 00:00 UTC | May 30, 04:50 UTC | 4h 50m |
| 2026-05-29 | UAL6 | NRT → IAH | May 29, 08:30 UTC | May 29, 19:55 UTC | 11h 25m |
| 2026-05-29 | UAL6 | NRT → IAH | May 29, 08:26 UTC | May 29, 19:53 UTC | 11h 27m |
| 2026-05-29 | UAL32 | LAX → NRT | May 29, 04:40 UTC | May 29, 05:25 UTC | 45m |
| 2026-05-28 | UAL32 | LAX → NRT | May 28, 18:25 UTC | May 28, 19:35 UTC | 1h 10m |
| 2026-05-28 | UAL32 | LAX → NRT | May 28, 18:30 UTC | May 29, 05:22 UTC | 10h 52m |
| 2026-05-27 | UAL821 | SFO → MEX | May 27, 14:40 UTC | May 28, 03:50 UTC | 13h 10m |
| 2026-05-27 | UAL821 | SFO → MEX | May 27, 10:20 UTC | May 27, 12:40 UTC | 2h 20m |
| 2026-05-27 | UAL820 | MEX → SFO | May 27, 01:34 UTC | May 27, 01:44 UTC | 10m |
| 2026-05-27 | UAL820 | MEX → SFO | May 27, 00:00 UTC | May 27, 00:10 UTC | 10m |
| 2026-05-27 | UAL820 | MEX → SFO | May 27, 00:01 UTC | May 27, 02:02 UTC | 2h 1m |
| 2026-05-26 | UAL820 | MEX → SFO | May 26, 07:19 UTC | May 26, 21:34 UTC | 14h 15m |
| 2026-05-25 | UAL353 | SAN → EWR | May 25, 23:00 UTC | May 26, 04:04 UTC | 5h 5m |
| 2026-05-24 | UAL83 | DEL → EWR | May 24, 20:20 UTC | May 25, 11:55 UTC | 15h 35m |
| 2026-05-24 | UAL82 | EWR → DEL | May 24, 02:25 UTC | May 24, 16:10 UTC | 13h 45m |
| 2026-05-23 | UAL713 | ORD → DEL | May 23, 19:15 UTC | May 23, 23:42 UTC | 4h 27m |
| 2026-05-23 | UAL713 | ORD → DEL | May 23, 19:05 UTC | May 23, 23:50 UTC | 4h 45m |
| 2026-05-23 | UAL806 | ICN → SFO | May 23, 02:45 UTC | May 23, 12:40 UTC | 9h 55m |
| 2026-05-23 | UAL806 | ICN → SFO | May 23, 02:35 UTC | May 23, 02:40 UTC | 5m |
| 2026-05-22 | UAL805 | SFO → ICN | May 22, 08:06 UTC | May 22, 19:54 UTC | 11h 48m |
| 2026-05-22 | UAL805 | SFO → ICN | May 22, 08:05 UTC | May 22, 20:00 UTC | 11h 55m |
| 2026-05-22 | UAL28 | SIN → SFO | May 22, 04:10 UTC | May 22, 04:15 UTC | 5m |
| 2026-05-21 | UAL28 | SIN → SFO | May 21, 16:15 UTC | May 21, 16:55 UTC | 40m |
| 2026-05-21 | UAL28 | SIN → SFO | May 21, 13:21 UTC | May 22, 03:51 UTC | 14h 30m |
| 2026-05-12 | UAL29 | SFO → SIN | May 12, 06:45 UTC | May 12, 22:39 UTC | 15h 54m |
| 2026-05-12 | UAL29 | SFO → SIN | May 12, 06:55 UTC | May 12, 11:25 UTC | 4h 30m |
| 2026-05-11 | UAL61 | BRU → EWR | May 11, 01:09 UTC | May 11, 14:34 UTC | 13h 25m |
| 2026-05-11 | UAL61 | BRU → EWR | May 11, 01:15 UTC | May 11, 14:40 UTC | 13h 25m |
| 2026-05-10 | UAL60 | SFO → MEL | May 10, 07:04 UTC | May 10, 07:30 UTC | 25m |
| 2026-05-10 | UAL60 | SFO → MEL | May 10, 06:51 UTC | May 10, 22:38 UTC | 15h 47m |
| 2026-05-09 | UAL892 | ICN → SFO | May 9, 08:25 UTC | May 9, 18:25 UTC | 10h 0m |
| 2026-05-09 | UAL892 | ICN → SFO | May 9, 08:26 UTC | May 9, 18:19 UTC | 9h 53m |
| 2026-05-08 | UAL893 | SFO → ICN | May 8, 18:05 UTC | May 9, 06:20 UTC | 12h 15m |
| 2026-05-08 | UAL806 | ICN → SFO | May 8, 02:44 UTC | May 8, 12:34 UTC | 9h 50m |
| 2026-05-07 | UAL805 | SFO → ICN | May 7, 07:40 UTC | May 7, 19:20 UTC | 11h 40m |
| 2026-05-05 | UAL892 | ICN → SFO | May 5, 08:10 UTC | May 5, 18:10 UTC | 10h 0m |
| 2026-05-04 | UAL893 | SFO → ICN | May 4, 17:50 UTC | May 5, 05:51 UTC | 12h 1m |
| 2026-05-04 | UAL893 | SFO → ICN | May 4, 17:55 UTC | May 5, 05:50 UTC | 11h 56m |
| 2026-05-04 | UAL114 | PPT → SFO | May 4, 07:35 UTC | May 4, 15:00 UTC | 7h 25m |
| 2026-05-03 | UAL115 | SFO → PPT | May 3, 21:00 UTC | May 4, 05:20 UTC | 8h 20m |
| 2026-05-03 | UAL115 | SFO → PPT | May 3, 20:37 UTC | May 4, 05:14 UTC | 8h 37m |
| 2026-05-03 | UAL61 | BRU → EWR | May 3, 01:44 UTC | May 3, 15:18 UTC | 13h 34m |
| 2026-05-03 | UAL61 | BRU → EWR | May 3, 02:00 UTC | May 3, 15:20 UTC | 13h 19m |
| 2026-05-02 | UAL60 | SFO → MEL | May 2, 08:20 UTC | May 2, 23:30 UTC | 15h 10m |
| 2026-05-01 | UAL1757 | PIT → DEN | May 1, 22:20 UTC | May 2, 03:20 UTC | 5h 0m |
| 2026-05-01 | UAL1849 | MCO → EWR | May 1, 15:35 UTC | May 1, 19:50 UTC | 4h 15m |
| 2026-05-01 | UAL806 | ICN → SFO | May 1, 02:45 UTC | May 1, 12:55 UTC | 10h 10m |
| 2026-04-30 | UAL805 | SFO → ICN | Apr 30, 07:20 UTC | Apr 30, 19:10 UTC | 11h 50m |
| 2026-04-29 | UAL1757 | PIT → DEN | Apr 29, 23:15 UTC | Apr 30, 04:40 UTC | 5h 25m |
| 2026-04-29 | UAL2023 | BOS → ORD | Apr 29, 01:05 UTC | Apr 29, 08:50 UTC | 7h 45m |
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 N24973 page for operator, model, and routing details .