sensors Mode-S transponder
A219EA
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N2341U · BOEING 777-300ER · operated by UNITED AIRLINES INC
- Hex
- A219EA
- Octal
- 50414752
- Decimal
- 10,623,466
- Country
- US
- Tail
- N2341U
- Type
- B77W
- Flights observed
- 232
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 10h ago
Last known position
Country allocation
The ICAO 24-bit address A219EA 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 |
|---|---|---|---|
| UAL857 | - | 14 | 2026-07-09 |
| UAL872 | - | 13 | 2026-07-08 |
| UAL871 | - | 11 | 2026-07-06 |
| UAL1960 | - | 11 | 2026-07-06 |
| UAL858 | - | 10 | 2026-07-10 |
| UAL41 | United Airlines | 9 | 2026-05-25 |
| UAL988 | - | 8 | 2026-07-03 |
| UAL951 | United Airlines | 8 | 2026-07-04 |
| UAL869 | United Airlines | 8 | 2026-05-30 |
| UAL78 | United Airlines | 8 | 2026-06-25 |
| UAL40 | United Airlines | 8 | 2026-05-24 |
| UAL1175 | - | 8 | 2026-06-30 |
| UAL989 | - | 7 | 2026-07-05 |
| UAL950 | - | 7 | 2026-07-03 |
| UAL79 | - | 7 | 2026-06-22 |
| UAL43 | - | 7 | 2026-07-05 |
| UAL201 | - | 7 | 2026-07-01 |
| UAL810 | - | 6 | 2026-07-11 |
| UAL809 | - | 6 | 2026-07-10 |
| UAL2416 | - | 6 | 2026-06-22 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-13 | UAL1844 | EWR → SFO | Jul 13, 23:24 UTC | Jul 14, 04:22 UTC | 4h 58m |
| 2026-07-13 | UAL1844 | - | Jul 13, 23:20 UTC | Jul 14, 04:30 UTC | 5h 10m |
| 2026-07-13 | UAL435 | - | Jul 13, 15:55 UTC | Jul 13, 20:50 UTC | 4h 55m |
| 2026-07-13 | UAL190 | - | Jul 13, 00:55 UTC | Jul 13, 13:15 UTC | 12h 20m |
| 2026-07-12 | UAL189 | SFO → MNL | Jul 12, 08:15 UTC | Jul 12, 21:40 UTC | 13h 25m |
| 2026-07-11 | UAL810 | - | Jul 11, 13:40 UTC | Jul 12, 01:50 UTC | 12h 10m |
| 2026-07-11 | UAL810 | MNL → SFO | Jul 11, 13:41 UTC | Jul 12, 01:46 UTC | 12h 5m |
| 2026-07-10 | UAL809 | SFO → MNL | Jul 10, 22:00 UTC | Jul 11, 11:20 UTC | 13h 20m |
| 2026-07-10 | UAL858 | - | Jul 10, 05:20 UTC | Jul 10, 15:25 UTC | 10h 5m |
| 2026-07-10 | UAL858 | PVG → SFO | Jul 10, 04:44 UTC | Jul 10, 15:20 UTC | 10h 36m |
| 2026-07-09 | UAL857 | - | Jul 9, 06:35 UTC | Jul 10, 06:30 UTC | 23h 55m |
| 2026-07-08 | UAL857 | SFO → PVG | Jul 8, 20:57 UTC | Jul 9, 09:01 UTC | 12h 4m |
| 2026-07-08 | UAL857 | - | Jul 8, 20:55 UTC | Jul 9, 08:05 UTC | 11h 10m |
| 2026-07-08 | UAL872 | - | Jul 8, 03:40 UTC | Jul 8, 13:20 UTC | 9h 40m |
| 2026-07-08 | UAL872 | - | Jul 8, 02:10 UTC | Jul 8, 02:25 UTC | 15m |
| 2026-07-06 | UAL871 | - | Jul 6, 22:45 UTC | Jul 6, 23:10 UTC | 25m |
| 2026-07-06 | UAL871 | SFO → TPE | Jul 6, 22:35 UTC | Jul 7, 10:51 UTC | 12h 16m |
| 2026-07-06 | UAL1960 | - | Jul 6, 15:05 UTC | Jul 6, 20:05 UTC | 5h 0m |
| 2026-07-05 | UAL43 | FRA → EWR | Jul 5, 11:45 UTC | Jul 5, 19:50 UTC | 8h 5m |
| 2026-07-05 | UAL989 | IAD → FRA | Jul 5, 01:40 UTC | Jul 5, 08:55 UTC | 7h 15m |
| 2026-07-04 | UAL951 | BRU → IAD | Jul 4, 10:27 UTC | Jul 4, 18:18 UTC | 7h 51m |
| 2026-07-04 | UAL951 | BRU → IAD | Jul 4, 10:27 UTC | Jul 4, 18:24 UTC | 7h 57m |
| 2026-07-04 | UAL951 | BRU → IAD | Jul 4, 10:25 UTC | Jul 4, 12:10 UTC | 1h 45m |
| 2026-07-03 | UAL950 | IAD → BRU | Jul 3, 22:40 UTC | Jul 4, 05:20 UTC | 6h 40m |
| 2026-07-03 | UAL988 | - | Jul 3, 11:15 UTC | Jul 3, 12:30 UTC | 1h 15m |
| 2026-07-03 | UAL988 | FRA → IAD | Jul 3, 11:19 UTC | Jul 3, 19:20 UTC | 8h 1m |
| 2026-07-03 | UAL42 | EWR → FRA | Jul 3, 01:10 UTC | Jul 3, 08:10 UTC | 7h 0m |
| 2026-07-02 | UAL435 | SFO → EWR | Jul 2, 15:40 UTC | Jul 2, 20:30 UTC | 4h 50m |
| 2026-07-02 | UAL1346 | - | Jul 2, 08:40 UTC | Jul 2, 13:00 UTC | 4h 20m |
| 2026-07-01 | UAL200 | GUM → HNL | Jul 1, 21:23 UTC | Jul 2, 03:54 UTC | 6h 31m |
| 2026-07-01 | UAL201 | - | Jul 1, 00:50 UTC | Jul 1, 01:05 UTC | 15m |
| 2026-07-01 | UAL201 | HNL → GUM | Jul 1, 00:44 UTC | Jul 1, 08:01 UTC | 7h 17m |
| 2026-06-30 | UAL1175 | - | Jun 30, 21:20 UTC | Jun 30, 21:35 UTC | 15m |
| 2026-06-30 | UAL1175 | - | Jun 30, 16:55 UTC | Jun 30, 17:25 UTC | 30m |
| 2026-06-30 | UAL872 | - | Jun 30, 04:25 UTC | Jun 30, 13:05 UTC | 8h 40m |
| 2026-06-30 | UAL872 | - | Jun 30, 02:10 UTC | Jun 30, 02:25 UTC | 15m |
| 2026-06-28 | UAL871 | SFO → TPE | Jun 28, 22:08 UTC | Jun 29, 10:27 UTC | 12h 19m |
| 2026-06-28 | UAL871 | - | Jun 28, 21:59 UTC | Jun 29, 10:29 UTC | 12h 30m |
| 2026-06-28 | UAL858 | - | Jun 28, 05:15 UTC | Jun 28, 14:54 UTC | 9h 40m |
| 2026-06-26 | UAL857 | SFO → PVG | Jun 26, 20:57 UTC | Jun 27, 09:29 UTC | 12h 32m |
| 2026-06-26 | UAL857 | - | Jun 26, 20:59 UTC | Jun 26, 21:24 UTC | 25m |
| 2026-06-26 | UAL1960 | - | Jun 26, 11:20 UTC | Jun 26, 16:44 UTC | 5h 25m |
| 2026-06-25 | UAL78 | NRT → EWR | Jun 25, 08:45 UTC | Jun 25, 21:10 UTC | 12h 25m |
| 2026-06-24 | UAL837 | SFO → NRT | Jun 24, 20:20 UTC | Jun 25, 06:09 UTC | 9h 50m |
| 2026-06-24 | UAL1960 | - | Jun 24, 11:14 UTC | Jun 24, 16:40 UTC | 5h 25m |
| 2026-06-23 | UAL78 | NRT → EWR | Jun 23, 08:39 UTC | Jun 23, 20:49 UTC | 12h 10m |
| 2026-06-22 | UAL79 | - | Jun 22, 16:05 UTC | Jun 23, 04:50 UTC | 12h 45m |
| 2026-06-22 | UAL2416 | SFO → EWR | Jun 22, 07:30 UTC | Jun 22, 12:35 UTC | 5h 5m |
| 2026-06-22 | UAL2416 | - | Jun 22, 07:45 UTC | Jun 22, 12:25 UTC | 4h 40m |
| 2026-06-21 | UAL810 | - | Jun 21, 13:59 UTC | Jun 22, 02:04 UTC | 12h 5m |
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 N2341U page for operator, model, and routing details .