sensors Mode-S transponder
A31A77
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N29985 · BOEING 787-9 Dreamliner · operated by WILMINGTON TRUST CO TRUSTEE
- Hex
- A31A77
- Octal
- 50615167
- Decimal
- 10,689,143
- Country
- US
- Tail
- N29985
- Type
- B789
- Flights observed
- 94
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 3h ago
Last known position
Country allocation
The ICAO 24-bit address A31A77 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 |
|---|---|---|---|
| UAL821 | United Airlines | 8 | 2026-05-26 |
| UAL820 | United Airlines | 8 | 2026-05-26 |
| UAL60 | United Airlines | 5 | 2026-04-19 |
| UAL28 | United Airlines | 5 | 2026-04-17 |
| UAL870 | United Airlines | 4 | 2026-04-15 |
| UAL863 | United Airlines | 4 | 2026-05-30 |
| UAL761 | United Airlines | 4 | 2026-05-19 |
| UAL760 | United Airlines | 4 | 2026-05-19 |
| UAL772 | United Airlines | 3 | 2026-04-23 |
| UAL263 | United Airlines | 3 | 2026-05-14 |
| UAL262 | United Airlines | 3 | 2026-05-14 |
| UAL78 | United Airlines | 2 | 2026-05-21 |
| UAL771 | United Airlines | 2 | 2026-04-22 |
| UAL7 | United Airlines | 2 | 2026-05-01 |
| UAL62 | United Airlines | 2 | 2026-04-30 |
| UAL61 | United Airlines | 2 | 2026-04-20 |
| UAL353 | United Airlines | 2 | 2026-05-27 |
| UAL29 | United Airlines | 2 | 2026-04-16 |
| UAL26 | United Airlines | 2 | 2026-05-04 |
| UAL2096 | United Airlines | 2 | 2026-05-27 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-30 | UAL863 | SFO → SYD | May 30, 06:35 UTC | May 30, 07:05 UTC | 30m |
| 2026-05-29 | UAL1960 | MCO → ORD | May 29, 13:50 UTC | May 29, 18:57 UTC | 5h 7m |
| 2026-05-29 | UAL1960 | MCO → ORD | May 29, 13:50 UTC | May 29, 19:05 UTC | 5h 15m |
| 2026-05-28 | UAL2480 | BOS → SFO | May 28, 21:15 UTC | May 29, 01:55 UTC | 4h 40m |
| 2026-05-28 | UAL1593 | LGA → DEN | May 28, 14:15 UTC | May 28, 19:25 UTC | 5h 10m |
| 2026-05-28 | UAL2303 | IAD → SAN | May 28, 06:40 UTC | May 28, 11:00 UTC | 4h 20m |
| 2026-05-27 | UAL353 | SAN → EWR | May 27, 23:55 UTC | May 28, 04:55 UTC | 5h 0m |
| 2026-05-27 | UAL2096 | LAX → EWR | May 27, 16:00 UTC | May 27, 20:45 UTC | 4h 45m |
| 2026-05-26 | UAL821 | SFO → MEX | May 26, 14:45 UTC | May 26, 17:50 UTC | 3h 5m |
| 2026-05-26 | UAL821 | SFO → MEX | May 26, 14:00 UTC | May 26, 14:14 UTC | 15m |
| 2026-05-26 | UAL821 | SFO → MEX | May 26, 14:06 UTC | May 27, 02:38 UTC | 12h 32m |
| 2026-05-26 | UAL821 | SFO → MEX | May 26, 11:15 UTC | May 26, 11:34 UTC | 20m |
| 2026-05-26 | UAL821 | SFO → MEX | May 26, 09:19 UTC | May 26, 09:49 UTC | 30m |
| 2026-05-26 | UAL820 | MEX → SFO | May 26, 01:49 UTC | May 26, 02:29 UTC | 40m |
| 2026-05-26 | UAL820 | MEX → SFO | May 26, 00:19 UTC | May 26, 00:29 UTC | 10m |
| 2026-05-26 | UAL820 | MEX → SFO | May 26, 00:01 UTC | May 26, 02:28 UTC | 2h 27m |
| 2026-05-25 | UAL820 | MEX → SFO | May 25, 07:15 UTC | May 25, 21:49 UTC | 14h 34m |
| 2026-05-24 | UAL353 | SAN → EWR | May 24, 23:30 UTC | May 25, 04:30 UTC | 5h 0m |
| 2026-05-21 | UAL78 | NRT → EWR | May 21, 08:50 UTC | May 21, 15:45 UTC | 6h 55m |
| 2026-05-21 | UAL78 | NRT → EWR | May 21, 08:51 UTC | May 21, 20:28 UTC | 11h 37m |
| 2026-05-20 | UAL143 | DEN → NRT | May 20, 18:05 UTC | May 21, 05:40 UTC | 11h 35m |
| 2026-05-19 | UAL761 | MUC → DEN | May 19, 14:40 UTC | May 20, 00:45 UTC | 10h 5m |
| 2026-05-19 | UAL761 | MUC → DEN | May 19, 14:39 UTC | May 20, 00:40 UTC | 10h 1m |
| 2026-05-19 | UAL760 | DEN → MUC | May 19, 03:06 UTC | May 19, 12:26 UTC | 9h 20m |
| 2026-05-19 | UAL760 | DEN → MUC | May 19, 03:15 UTC | May 19, 05:00 UTC | 1h 45m |
| 2026-05-18 | UAL178 | KIX → GUM | May 18, 12:50 UTC | May 18, 23:55 UTC | 11h 4m |
| 2026-05-17 | UAL177 | GUM → KIX | May 17, 23:45 UTC | May 18, 09:25 UTC | 9h 40m |
| 2026-05-17 | UAL181 | FRA → DEN | May 17, 09:40 UTC | May 17, 19:25 UTC | 9h 45m |
| 2026-05-16 | UAL182 | DEN → FRA | May 16, 22:10 UTC | May 17, 07:00 UTC | 8h 50m |
| 2026-05-15 | UAL761 | MUC → DEN | May 15, 14:20 UTC | May 16, 00:20 UTC | 9h 59m |
| 2026-05-15 | UAL760 | DEN → MUC | May 15, 02:40 UTC | May 15, 12:10 UTC | 9h 30m |
| 2026-05-14 | UAL263 | EWR → PBI | May 14, 14:25 UTC | May 14, 23:35 UTC | 9h 10m |
| 2026-05-14 | UAL262 | DEN → LHR | May 14, 02:50 UTC | May 14, 11:25 UTC | 8h 35m |
| 2026-05-14 | UAL262 | DEN → LHR | May 14, 02:50 UTC | May 14, 11:14 UTC | 8h 24m |
| 2026-05-09 | UAL143 | DEN → NRT | May 9, 18:10 UTC | May 9, 20:30 UTC | 2h 20m |
| 2026-05-07 | UAL761 | MUC → DEN | May 7, 14:30 UTC | May 8, 00:20 UTC | 9h 49m |
| 2026-05-07 | UAL760 | DEN → MUC | May 7, 02:45 UTC | May 7, 12:00 UTC | 9h 15m |
| 2026-05-06 | UAL263 | EWR → PBI | May 6, 14:10 UTC | May 6, 23:05 UTC | 8h 54m |
| 2026-05-06 | UAL263 | EWR → PBI | May 6, 14:14 UTC | May 6, 23:01 UTC | 8h 47m |
| 2026-05-06 | UAL262 | DEN → LHR | May 6, 03:40 UTC | May 6, 11:55 UTC | 8h 15m |
| 2026-05-05 | UAL178 | KIX → GUM | May 5, 12:40 UTC | May 5, 23:15 UTC | 10h 35m |
| 2026-05-04 | UAL177 | GUM → KIX | May 4, 23:55 UTC | May 5, 09:45 UTC | 9h 50m |
| 2026-05-04 | UAL26 | LHR → DEN | May 4, 11:00 UTC | May 4, 12:10 UTC | 1h 10m |
| 2026-05-04 | UAL26 | LHR → DEN | May 4, 10:50 UTC | May 4, 19:59 UTC | 9h 9m |
| 2026-05-04 | UAL27 | DEN → LHR | May 4, 00:10 UTC | May 4, 08:55 UTC | 8h 45m |
| 2026-05-03 | UAL181 | FRA → DEN | May 3, 09:40 UTC | May 3, 19:10 UTC | 9h 30m |
| 2026-05-02 | UAL182 | DEN → FRA | May 2, 22:00 UTC | May 3, 07:15 UTC | 9h 14m |
| 2026-05-02 | UAL142 | NRT → DEN | May 2, 07:55 UTC | May 2, 18:05 UTC | 10h 10m |
| 2026-05-01 | UAL7 | IAH → NRT | May 1, 16:10 UTC | May 2, 05:30 UTC | 13h 20m |
| 2026-05-01 | UAL7 | IAH → NRT | May 1, 15:47 UTC | May 2, 05:29 UTC | 13h 42m |
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 N29985 page for operator, model, and routing details .