sensors Mode-S transponder
A31A2D
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N29961 · BOEING 787-9 Dreamliner · operated by UNITED AIRLINES INC
- Hex
- A31A2D
- Octal
- 50615055
- Decimal
- 10,689,069
- Country
- US
- Tail
- N29961
- Type
- B789
- Flights observed
- 205
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 52m ago
Current position
Country allocation
The ICAO 24-bit address A31A2D 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 |
|---|---|---|---|
| UAL2222 | - | 8 | 2026-06-26 |
| UAL198 | - | 8 | 2026-06-29 |
| UAL820 | - | 7 | 2026-06-16 |
| UAL152 | United Airlines | 7 | 2026-05-26 |
| UAL870 | - | 6 | 2026-07-01 |
| UAL821 | - | 6 | 2026-06-17 |
| UAL2096 | United Airlines | 6 | 2026-06-24 |
| UAL199 | United Airlines | 6 | 2026-06-29 |
| UAL153 | United Airlines | 6 | 2026-05-27 |
| UAL122 | - | 6 | 2026-07-03 |
| UAL1122 | - | 6 | 2026-06-25 |
| UAL62 | - | 5 | 2026-07-10 |
| UAL61 | United Airlines | 5 | 2026-06-03 |
| UAL29 | United Airlines | 5 | 2026-06-03 |
| UAL2023 | United Airlines | 5 | 2026-05-05 |
| UAL187 | - | 5 | 2026-06-22 |
| UAL83 | United Airlines | 4 | 2026-07-05 |
| UAL78 | United Airlines | 4 | 2026-04-14 |
| UAL63 | - | 4 | 2026-07-11 |
| UAL60 | United Airlines | 4 | 2026-06-02 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-14 | UAL26 | - | Jul 14, 12:30 UTC | Jul 14, 19:15 UTC | 6h 45m |
| 2026-07-14 | UAL27 | DEN → LHR | Jul 14, 00:10 UTC | Jul 14, 08:40 UTC | 8h 30m |
| 2026-07-13 | UAL27 | DEN → LHR | Jul 13, 23:58 UTC | Jul 14, 08:28 UTC | 8h 30m |
| 2026-07-13 | UAL181 | - | Jul 13, 09:45 UTC | Jul 13, 19:15 UTC | 9h 30m |
| 2026-07-13 | UAL181 | FRA → DEN | Jul 13, 09:51 UTC | Jul 13, 19:11 UTC | 9h 20m |
| 2026-07-12 | UAL182 | DEN → FRA | Jul 12, 22:35 UTC | Jul 13, 07:35 UTC | 9h 0m |
| 2026-07-12 | UAL142 | - | Jul 12, 07:50 UTC | Jul 12, 08:20 UTC | 30m |
| 2026-07-12 | UAL142 | NRT → DEN | Jul 12, 07:50 UTC | Jul 12, 17:49 UTC | 9h 59m |
| 2026-07-12 | UAL142 | NRT → DEN | Jul 12, 07:50 UTC | Jul 12, 17:51 UTC | 10h 1m |
| 2026-07-11 | UAL7 | - | Jul 11, 16:15 UTC | Jul 12, 04:50 UTC | 12h 35m |
| 2026-07-11 | UAL63 | GRU → IAH | Jul 11, 01:11 UTC | Jul 11, 10:33 UTC | 9h 22m |
| 2026-07-10 | UAL62 | IAH → GRU | Jul 10, 00:03 UTC | Jul 10, 09:06 UTC | 9h 3m |
| 2026-07-09 | UAL62 | - | Jul 9, 23:55 UTC | Jul 10, 04:50 UTC | 4h 55m |
| 2026-07-09 | UAL6 | - | Jul 9, 08:20 UTC | Jul 9, 19:45 UTC | 11h 25m |
| 2026-07-09 | UAL6 | NRT → IAH | Jul 9, 08:26 UTC | Jul 9, 19:45 UTC | 11h 19m |
| 2026-07-08 | UAL32 | LAX → NRT | Jul 8, 18:15 UTC | Jul 9, 04:50 UTC | 10h 35m |
| 2026-07-08 | UAL32 | - | Jul 8, 18:15 UTC | Jul 9, 04:55 UTC | 10h 40m |
| 2026-07-08 | UAL99 | - | Jul 8, 00:00 UTC | Jul 8, 13:30 UTC | 13h 30m |
| 2026-07-07 | UAL98 | LAX → MEL | Jul 7, 06:20 UTC | Jul 7, 21:40 UTC | 15h 20m |
| 2026-07-06 | UAL2692 | EWR → LAX | Jul 6, 13:49 UTC | Jul 6, 18:25 UTC | 4h 36m |
| 2026-07-06 | UAL2692 | - | Jul 6, 13:35 UTC | Jul 6, 18:30 UTC | 4h 55m |
| 2026-07-05 | UAL83 | DEL → EWR | Jul 5, 18:25 UTC | Jul 5, 19:00 UTC | 35m |
| 2026-07-05 | UAL83 | DEL → EWR | Jul 5, 18:32 UTC | Jul 6, 10:07 UTC | 15h 35m |
| 2026-07-05 | UAL82 | EWR → DEL | Jul 5, 01:44 UTC | Jul 5, 15:28 UTC | 13h 44m |
| 2026-07-05 | UAL82 | - | Jul 5, 01:40 UTC | Jul 5, 11:55 UTC | 10h 15m |
| 2026-07-04 | UAL123 | - | Jul 4, 07:00 UTC | Jul 4, 14:10 UTC | 7h 10m |
| 2026-07-04 | UAL123 | LHR → EWR | Jul 4, 06:52 UTC | Jul 4, 14:05 UTC | 7h 13m |
| 2026-07-03 | UAL122 | EWR → LHR | Jul 3, 15:05 UTC | Jul 3, 21:20 UTC | 6h 15m |
| 2026-07-03 | UAL122 | EWR → LHR | Jul 3, 14:09 UTC | Jul 3, 21:15 UTC | 7h 6m |
| 2026-07-02 | UAL83 | DEL → EWR | Jul 2, 18:40 UTC | Jul 3, 10:25 UTC | 15h 45m |
| 2026-07-02 | UAL83 | DEL → EWR | Jul 2, 18:36 UTC | Jul 3, 10:17 UTC | 15h 41m |
| 2026-07-02 | UAL82 | EWR → DEL | Jul 2, 02:30 UTC | Jul 2, 16:15 UTC | 13h 45m |
| 2026-07-01 | UAL713 | - | Jul 1, 17:55 UTC | Jul 1, 22:35 UTC | 4h 40m |
| 2026-07-01 | UAL870 | - | Jul 1, 01:15 UTC | Jul 1, 13:55 UTC | 12h 40m |
| 2026-06-30 | UAL839 | - | Jun 30, 07:15 UTC | Jun 30, 21:40 UTC | 14h 25m |
| 2026-06-30 | UAL839 | LAX → SYD | Jun 30, 07:03 UTC | Jun 30, 21:38 UTC | 14h 35m |
| 2026-06-29 | UAL199 | PVG → LAX | Jun 29, 12:09 UTC | Jun 30, 04:40 UTC | 16h 31m |
| 2026-06-29 | UAL198 | - | Jun 29, 02:14 UTC | Jun 29, 19:54 UTC | 17h 40m |
| 2026-06-26 | UAL2692 | - | Jun 26, 13:40 UTC | Jun 26, 18:29 UTC | 4h 50m |
| 2026-06-26 | UAL2222 | - | Jun 26, 07:24 UTC | Jun 26, 08:40 UTC | 1h 15m |
| 2026-06-25 | UAL2222 | CPT → EWR | Jun 25, 18:12 UTC | Jun 26, 08:38 UTC | 14h 26m |
| 2026-06-25 | UAL2222 | - | Jun 25, 18:00 UTC | Jun 25, 18:10 UTC | 10m |
| 2026-06-25 | UAL1122 | - | Jun 25, 14:50 UTC | Jun 25, 15:15 UTC | 25m |
| 2026-06-25 | UAL1122 | - | Jun 25, 01:35 UTC | Jun 25, 08:30 UTC | 6h 55m |
| 2026-06-24 | UAL2096 | LAX → EWR | Jun 24, 15:59 UTC | Jun 24, 20:30 UTC | 4h 30m |
| 2026-06-23 | UAL2403 | - | Jun 23, 16:24 UTC | Jun 23, 21:39 UTC | 5h 15m |
| 2026-06-22 | UAL187 | - | Jun 22, 20:10 UTC | Jun 23, 11:14 UTC | 15h 5m |
| 2026-06-22 | UAL188 | EWR → JNB | Jun 22, 01:55 UTC | Jun 22, 16:14 UTC | 14h 20m |
| 2026-06-21 | UAL2303 | - | Jun 21, 06:29 UTC | Jun 21, 10:44 UTC | 4h 15m |
| 2026-06-20 | UAL353 | - | Jun 20, 23:14 UTC | Jun 21, 04:24 UTC | 5h 10m |
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 N29961 page for operator, model, and routing details .