sensors Mode-S transponder
A254D6
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N24972 · BOEING 787-9 Dreamliner · operated by UNITED AIRLINES INC
- Hex
- A254D6
- Octal
- 50452326
- Decimal
- 10,638,550
- Country
- US
- Tail
- N24972
- Type
- B789
- Flights observed
- 114
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 1h ago
Last known position
Country allocation
The ICAO 24-bit address A254D6 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 |
|---|---|---|---|
| UAL78 | United Airlines | 6 | 2026-04-17 |
| UAL143 | United Airlines | 6 | 2026-04-17 |
| UAL892 | United Airlines | 5 | 2026-05-16 |
| UAL82 | United Airlines | 5 | 2026-04-21 |
| UAL178 | United Airlines | 5 | 2026-04-15 |
| UAL1227 | United Airlines | 5 | 2026-05-27 |
| UAL893 | United Airlines | 4 | 2026-05-15 |
| UAL27 | United Airlines | 4 | 2026-04-13 |
| UAL263 | United Airlines | 4 | 2026-04-15 |
| UAL26 | United Airlines | 4 | 2026-04-13 |
| UAL870 | United Airlines | 3 | 2026-05-15 |
| UAL863 | United Airlines | 3 | 2026-05-28 |
| UAL83 | United Airlines | 3 | 2026-04-21 |
| UAL713 | United Airlines | 3 | 2026-05-17 |
| UAL262 | United Airlines | 3 | 2026-04-15 |
| UAL198 | United Airlines | 3 | 2026-05-24 |
| UAL152 | United Airlines | 3 | 2026-04-24 |
| UAL805 | United Airlines | 2 | 2026-05-10 |
| UAL62 | United Airlines | 2 | 2026-05-21 |
| UAL6 | United Airlines | 2 | 2026-05-20 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-30 | UAL1122 | EWR → CPT | May 30, 00:55 UTC | May 30, 01:25 UTC | 30m |
| 2026-05-29 | UAL2096 | LAX → EWR | May 29, 16:30 UTC | May 29, 21:00 UTC | 4h 30m |
| 2026-05-29 | UAL842 | SYD → LAX | May 29, 00:15 UTC | May 29, 13:30 UTC | 13h 15m |
| 2026-05-28 | UAL863 | SFO → SYD | May 28, 06:45 UTC | May 28, 20:45 UTC | 14h 0m |
| 2026-05-27 | UAL1227 | PHX → IAD | May 27, 19:25 UTC | May 27, 23:05 UTC | 3h 40m |
| 2026-05-27 | UAL1227 | PHX → IAD | May 27, 17:40 UTC | May 27, 19:20 UTC | 1h 40m |
| 2026-05-27 | UAL123 | ANC → ORD | May 27, 06:55 UTC | May 27, 13:40 UTC | 6h 45m |
| 2026-05-26 | UAL122 | IAD → LHR | May 26, 13:54 UTC | May 26, 20:15 UTC | 6h 20m |
| 2026-05-25 | UAL2480 | BOS → SFO | May 25, 22:25 UTC | May 26, 02:55 UTC | 4h 30m |
| 2026-05-25 | UAL1593 | LGA → DEN | May 25, 14:50 UTC | May 25, 20:04 UTC | 5h 15m |
| 2026-05-25 | UAL2303 | IAD → SAN | May 25, 06:20 UTC | May 25, 10:45 UTC | 4h 25m |
| 2026-05-25 | UAL2303 | IAD → SAN | May 25, 06:34 UTC | May 25, 10:43 UTC | 4h 9m |
| 2026-05-24 | UAL199 | PVG → LAX | May 24, 06:40 UTC | May 24, 23:46 UTC | 17h 6m |
| 2026-05-24 | UAL198 | LAX → PVG | May 24, 01:35 UTC | May 24, 23:46 UTC | 22h 11m |
| 2026-05-24 | UAL198 | LAX → PVG | May 24, 00:35 UTC | May 24, 23:30 UTC | 22h 55m |
| 2026-05-23 | UAL198 | LAX → PVG | May 23, 20:30 UTC | May 24, 15:00 UTC | 18h 30m |
| 2026-05-23 | UAL33 | NRT → LAX | May 23, 08:00 UTC | May 23, 17:15 UTC | 9h 15m |
| 2026-05-22 | UAL7 | IAH → NRT | May 22, 15:55 UTC | May 23, 04:35 UTC | 12h 39m |
| 2026-05-22 | UAL63 | GRU → IAH | May 22, 01:10 UTC | May 22, 10:25 UTC | 9h 15m |
| 2026-05-21 | UAL62 | IAH → GRU | May 21, 00:05 UTC | May 21, 01:30 UTC | 1h 25m |
| 2026-05-21 | UAL62 | IAH → GRU | May 21, 00:03 UTC | May 21, 08:53 UTC | 8h 50m |
| 2026-05-20 | UAL6 | NRT → IAH | May 20, 08:20 UTC | May 20, 19:30 UTC | 11h 10m |
| 2026-05-20 | UAL6 | NRT → IAH | May 20, 08:26 UTC | May 20, 19:32 UTC | 11h 6m |
| 2026-05-19 | UAL79 | EWR → NRT | May 19, 15:45 UTC | May 20, 04:50 UTC | 13h 6m |
| 2026-05-18 | UAL187 | JNB → EWR | May 18, 20:15 UTC | May 19, 04:30 UTC | 8h 15m |
| 2026-05-18 | UAL187 | JNB → EWR | May 18, 20:19 UTC | May 19, 12:06 UTC | 15h 47m |
| 2026-05-18 | UAL188 | EWR → JNB | May 18, 01:55 UTC | May 18, 15:40 UTC | 13h 45m |
| 2026-05-17 | UAL713 | ORD → DEL | May 17, 18:20 UTC | May 17, 22:49 UTC | 4h 29m |
| 2026-05-17 | UAL713 | ORD → DEL | May 17, 18:15 UTC | May 17, 22:45 UTC | 4h 30m |
| 2026-05-16 | UAL892 | ICN → SFO | May 16, 10:26 UTC | May 16, 20:14 UTC | 9h 48m |
| 2026-05-16 | UAL892 | ICN → SFO | May 16, 10:20 UTC | May 16, 12:11 UTC | 1h 50m |
| 2026-05-15 | UAL893 | SFO → ICN | May 15, 20:45 UTC | May 16, 08:20 UTC | 11h 36m |
| 2026-05-15 | UAL870 | SYD → SFO | May 15, 00:55 UTC | May 15, 13:50 UTC | 12h 55m |
| 2026-05-14 | UAL863 | SFO → SYD | May 14, 06:51 UTC | May 14, 21:27 UTC | 14h 36m |
| 2026-05-14 | UAL863 | SFO → SYD | May 14, 07:10 UTC | May 14, 07:35 UTC | 25m |
| 2026-05-13 | UAL900 | LHR → SFO | May 13, 10:25 UTC | May 13, 20:55 UTC | 10h 30m |
| 2026-05-12 | UAL901 | SFO → LHR | May 12, 20:50 UTC | May 13, 06:30 UTC | 9h 40m |
| 2026-05-12 | UAL892 | ICN → SFO | May 12, 08:05 UTC | May 12, 18:05 UTC | 10h 0m |
| 2026-05-11 | UAL893 | SFO → ICN | May 11, 17:55 UTC | May 12, 05:10 UTC | 11h 15m |
| 2026-05-11 | UAL806 | ICN → SFO | May 11, 02:45 UTC | May 11, 13:05 UTC | 10h 20m |
| 2026-05-10 | UAL805 | SFO → ICN | May 10, 07:11 UTC | May 10, 18:20 UTC | 11h 9m |
| 2026-05-10 | UAL805 | SFO → ICN | May 10, 06:55 UTC | May 10, 18:20 UTC | 11h 25m |
| 2026-05-09 | UAL1757 | PIT → DEN | May 9, 22:25 UTC | May 10, 03:35 UTC | 5h 10m |
| 2026-05-08 | UAL2023 | BOS → ORD | May 8, 18:10 UTC | May 9, 09:45 UTC | 15h 35m |
| 2026-05-07 | UAL1011 | MCI → SFO | May 7, 23:09 UTC | May 8, 13:05 UTC | 13h 55m |
| 2026-05-07 | UAL1849 | MCO → EWR | May 7, 15:25 UTC | May 7, 19:50 UTC | 4h 25m |
| 2026-05-06 | UAL1227 | PHX → IAD | May 6, 17:50 UTC | May 6, 23:00 UTC | 5h 10m |
| 2026-05-05 | UAL1855 | ORD → BOS | May 5, 20:50 UTC | May 6, 01:05 UTC | 4h 15m |
| 2026-05-04 | UAL3931 | EWR → CLE | May 4, 20:30 UTC | May 4, 21:40 UTC | 1h 10m |
| 2026-05-04 | UAL870 | SYD → SFO | May 4, 14:50 UTC | May 4, 15:25 UTC | 35m |
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 N24972 page for operator, model, and routing details .