sensors Mode-S transponder
A254DA
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N24976 · BOEING 787-9 Dreamliner · operated by UNITED AIRLINES INC
- Hex
- A254DA
- Octal
- 50452332
- Decimal
- 10,638,554
- Country
- US
- Tail
- N24976
- Type
- B789
- Flights observed
- 84
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 8d ago
Last known position
Country allocation
The ICAO 24-bit address A254DA 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 |
|---|---|---|---|
| UAL82 | United Airlines | 7 | 2026-04-17 |
| UAL83 | United Airlines | 6 | 2026-04-18 |
| UAL892 | United Airlines | 5 | 2026-05-17 |
| UAL893 | United Airlines | 4 | 2026-05-16 |
| UAL820 | United Airlines | 4 | 2026-05-01 |
| UAL60 | United Airlines | 4 | 2026-05-11 |
| UAL28 | United Airlines | 4 | 2026-05-19 |
| UAL115 | United Airlines | 4 | 2026-05-12 |
| UAL821 | United Airlines | 3 | 2026-05-01 |
| UAL713 | United Airlines | 3 | 2026-04-16 |
| UAL61 | United Airlines | 3 | 2026-05-12 |
| UAL29 | United Airlines | 3 | 2026-05-18 |
| UAL198 | United Airlines | 3 | 2026-04-24 |
| UAL114 | United Airlines | 3 | 2026-05-13 |
| UAL863 | United Airlines | 2 | 2026-05-08 |
| UAL805 | United Airlines | 2 | 2026-05-15 |
| UAL7 | United Airlines | 2 | 2026-04-22 |
| UAL3887 | United Airlines | 2 | 2026-05-20 |
| UAL33 | United Airlines | 2 | 2026-04-28 |
| UAL32 | United Airlines | 2 | 2026-05-02 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-20 | UAL3887 | PDX → SFO | May 20, 16:09 UTC | May 21, 06:26 UTC | 14h 17m |
| 2026-05-20 | UAL3887 | PDX → SFO | May 20, 16:30 UTC | May 21, 04:15 UTC | 11h 45m |
| 2026-05-19 | UAL28 | SIN → SFO | May 19, 13:06 UTC | May 20, 03:36 UTC | 14h 30m |
| 2026-05-19 | UAL28 | SIN → SFO | May 19, 15:55 UTC | May 20, 03:45 UTC | 11h 50m |
| 2026-05-18 | UAL29 | SFO → SIN | May 18, 18:05 UTC | May 19, 10:06 UTC | 16h 1m |
| 2026-05-18 | UAL29 | SFO → SIN | May 18, 18:00 UTC | May 19, 08:30 UTC | 14h 29m |
| 2026-05-17 | UAL892 | ICN → SFO | May 17, 08:00 UTC | May 17, 18:01 UTC | 10h 0m |
| 2026-05-16 | UAL893 | SFO → ICN | May 16, 18:05 UTC | May 17, 05:40 UTC | 11h 35m |
| 2026-05-16 | UAL806 | ICN → SFO | May 16, 02:35 UTC | May 16, 12:35 UTC | 10h 1m |
| 2026-05-15 | UAL805 | SFO → ICN | May 15, 07:34 UTC | May 15, 19:00 UTC | 11h 26m |
| 2026-05-15 | UAL805 | SFO → ICN | May 15, 07:30 UTC | May 15, 12:50 UTC | 5h 20m |
| 2026-05-14 | UAL892 | ICN → SFO | May 14, 08:10 UTC | May 14, 18:35 UTC | 10h 25m |
| 2026-05-13 | UAL893 | SFO → ICN | May 13, 18:30 UTC | May 14, 05:50 UTC | 11h 20m |
| 2026-05-13 | UAL114 | PPT → SFO | May 13, 08:30 UTC | May 13, 16:05 UTC | 7h 35m |
| 2026-05-12 | UAL115 | SFO → PPT | May 12, 22:12 UTC | May 13, 06:09 UTC | 7h 57m |
| 2026-05-12 | UAL115 | SFO → PPT | May 12, 22:35 UTC | May 13, 06:15 UTC | 7h 40m |
| 2026-05-12 | UAL61 | BRU → EWR | May 12, 02:45 UTC | May 12, 15:01 UTC | 12h 15m |
| 2026-05-11 | UAL60 | SFO → MEL | May 11, 07:05 UTC | May 11, 22:35 UTC | 15h 30m |
| 2026-05-10 | UAL28 | SIN → SFO | May 10, 08:54 UTC | May 11, 03:10 UTC | 18h 15m |
| 2026-05-10 | UAL28 | SIN → SFO | May 10, 07:30 UTC | May 11, 03:10 UTC | 19h 40m |
| 2026-05-09 | UAL29 | SFO → SIN | May 9, 18:35 UTC | May 10, 16:04 UTC | 21h 30m |
| 2026-05-09 | UAL870 | SYD → SFO | May 9, 01:05 UTC | May 9, 13:45 UTC | 12h 40m |
| 2026-05-08 | UAL863 | SFO → SYD | May 8, 06:31 UTC | May 8, 20:34 UTC | 14h 3m |
| 2026-05-08 | UAL863 | SFO → SYD | May 8, 06:25 UTC | May 8, 20:40 UTC | 14h 15m |
| 2026-05-07 | UAL1227 | PHX → IAD | May 7, 18:35 UTC | May 7, 23:55 UTC | 5h 20m |
| 2026-05-07 | UAL123 | ANC → ORD | May 7, 07:00 UTC | May 7, 14:15 UTC | 7h 15m |
| 2026-05-06 | UAL122 | IAD → LHR | May 6, 13:50 UTC | May 6, 20:05 UTC | 6h 14m |
| 2026-05-04 | UAL187 | JNB → EWR | May 4, 20:20 UTC | May 5, 12:00 UTC | 15h 40m |
| 2026-05-04 | UAL188 | EWR → JNB | May 4, 02:04 UTC | May 4, 15:40 UTC | 13h 35m |
| 2026-05-03 | UAL78 | NRT → EWR | May 3, 08:45 UTC | May 3, 20:49 UTC | 12h 5m |
| 2026-05-02 | UAL32 | LAX → NRT | May 2, 17:50 UTC | May 3, 04:55 UTC | 11h 4m |
| 2026-05-01 | UAL821 | SFO → MEX | May 1, 14:05 UTC | May 2, 02:45 UTC | 12h 41m |
| 2026-05-01 | UAL821 | SFO → MEX | May 1, 11:10 UTC | May 1, 11:20 UTC | 10m |
| 2026-05-01 | UAL821 | SFO → MEX | May 1, 09:10 UTC | May 1, 09:40 UTC | 30m |
| 2026-05-01 | UAL820 | MEX → SFO | May 1, 01:50 UTC | May 1, 04:10 UTC | 2h 20m |
| 2026-04-30 | UAL820 | MEX → SFO | Apr 30, 21:25 UTC | Apr 30, 21:40 UTC | 15m |
| 2026-04-30 | UAL820 | MEX → SFO | Apr 30, 06:30 UTC | Apr 30, 07:25 UTC | 55m |
| 2026-04-30 | UAL820 | MEX → SFO | Apr 30, 06:19 UTC | Apr 30, 21:10 UTC | 14h 51m |
| 2026-04-28 | UAL33 | NRT → LAX | Apr 28, 08:10 UTC | Apr 28, 17:25 UTC | 9h 15m |
| 2026-04-27 | UAL79 | EWR → NRT | Apr 27, 16:35 UTC | Apr 28, 06:05 UTC | 13h 30m |
| 2026-04-26 | UAL187 | JNB → EWR | Apr 26, 21:50 UTC | Apr 27, 13:35 UTC | 15h 45m |
| 2026-04-26 | UAL188 | EWR → JNB | Apr 26, 02:55 UTC | Apr 26, 16:30 UTC | 13h 35m |
| 2026-04-25 | UAL2096 | LAX → EWR | Apr 25, 15:50 UTC | Apr 25, 20:15 UTC | 4h 25m |
| 2026-04-24 | UAL198 | LAX → PVG | Apr 24, 06:35 UTC | Apr 24, 23:10 UTC | 16h 35m |
| 2026-04-23 | UAL198 | LAX → PVG | Apr 23, 20:35 UTC | Apr 24, 14:45 UTC | 18h 10m |
| 2026-04-23 | UAL198 | LAX → PVG | Apr 23, 20:10 UTC | Apr 24, 14:45 UTC | 18h 35m |
| 2026-04-23 | UAL33 | NRT → LAX | Apr 23, 07:55 UTC | Apr 23, 17:25 UTC | 9h 30m |
| 2026-04-22 | UAL7 | IAH → NRT | Apr 22, 17:40 UTC | Apr 23, 04:30 UTC | 10h 50m |
| 2026-04-22 | UAL7 | IAH → NRT | Apr 22, 15:50 UTC | Apr 22, 17:35 UTC | 1h 45m |
| 2026-04-22 | UAL63 | GRU → IAH | Apr 22, 01:30 UTC | Apr 22, 10:25 UTC | 8h 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 N24976 page for operator, model, and routing details .