sensors Mode-S transponder
A31A76
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N29984 · BOEING 787-9 Dreamliner · operated by WILMINGTON TRUST CO TRUSTEE
- Hex
- A31A76
- Octal
- 50615166
- Decimal
- 10,689,142
- Country
- US
- Tail
- N29984
- Type
- B789
- Flights observed
- 231
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- Jul 26, 11:20 UTC
Last known position
Country allocation
The ICAO 24-bit address A31A76 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 |
|---|---|---|---|
| UAL935 | United Airlines | 9 | 2026-07-22 |
| UAL152 | United Airlines | 8 | 2026-06-17 |
| UAL923 | United Airlines | 7 | 2026-07-21 |
| UAL199 | - | 7 | 2026-07-12 |
| UAL178 | United Airlines | 7 | 2026-06-11 |
| UAL153 | United Airlines | 7 | 2026-06-18 |
| UAL1227 | - | 7 | 2026-06-22 |
| UAL870 | United Airlines | 6 | 2026-07-24 |
| UAL760 | United Airlines | 6 | 2026-06-12 |
| UAL263 | United Airlines | 6 | 2026-05-10 |
| UAL198 | - | 6 | 2026-07-12 |
| UAL182 | United Airlines | 6 | 2026-06-08 |
| UAL78 | United Airlines | 5 | 2026-04-13 |
| UAL761 | United Airlines | 5 | 2026-06-12 |
| UAL7 | - | 5 | 2026-07-02 |
| UAL27 | United Airlines | 5 | 2026-06-09 |
| UAL262 | United Airlines | 5 | 2026-05-10 |
| UAL181 | United Airlines | 5 | 2026-06-09 |
| UAL177 | United Airlines | 5 | 2026-06-11 |
| UAL863 | - | 4 | 2026-06-23 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-25 | UAL187 | JNB → EWR | Jul 25, 20:05 UTC | Jul 26, 11:10 UTC | 15h 6m |
| 2026-07-25 | UAL18 | MXP → EWR | Jul 25, 08:06 UTC | Jul 25, 15:55 UTC | 7h 49m |
| 2026-07-25 | UAL18 | MXP → EWR | Jul 25, 08:06 UTC | Jul 25, 16:01 UTC | 7h 55m |
| 2026-07-25 | UAL188 | EWR → JNB | Jul 25, 01:55 UTC | Jul 25, 09:20 UTC | 7h 25m |
| 2026-07-24 | UAL713 | ORD → DEL | Jul 24, 17:50 UTC | Jul 24, 22:25 UTC | 4h 35m |
| 2026-07-24 | UAL870 | SYD → SFO | Jul 24, 01:15 UTC | Jul 24, 13:55 UTC | 12h 40m |
| 2026-07-24 | UAL870 | SYD → SFO | Jul 24, 01:05 UTC | Jul 24, 14:00 UTC | 12h 55m |
| 2026-07-23 | UAL839 | LAX → SYD | Jul 23, 06:30 UTC | Jul 23, 21:00 UTC | 14h 30m |
| 2026-07-23 | UAL839 | LAX → SYD | Jul 23, 06:24 UTC | Jul 23, 20:51 UTC | 14h 27m |
| 2026-07-22 | UAL935 | LHR → LAX | Jul 22, 12:55 UTC | Jul 22, 23:30 UTC | 10h 35m |
| 2026-07-22 | UAL935 | LHR → LAX | Jul 22, 12:30 UTC | Jul 22, 23:22 UTC | 10h 52m |
| 2026-07-21 | UAL923 | LAX → LHR | Jul 21, 23:05 UTC | Jul 22, 02:15 UTC | 3h 10m |
| 2026-07-20 | UAL935 | - | Jul 20, 12:40 UTC | Jul 20, 23:00 UTC | 10h 20m |
| 2026-07-20 | UAL948 | SFO → LHR | Jul 20, 00:40 UTC | Jul 20, 10:05 UTC | 9h 25m |
| 2026-07-19 | UAL114 | - | Jul 19, 07:45 UTC | Jul 19, 15:25 UTC | 7h 40m |
| 2026-07-18 | UAL115 | SFO → PPT | Jul 18, 21:40 UTC | Jul 19, 05:40 UTC | 8h 0m |
| 2026-07-18 | UAL115 | SFO → PPT | Jul 18, 21:42 UTC | Jul 19, 05:30 UTC | 7h 48m |
| 2026-07-18 | UAL114 | - | Jul 18, 07:30 UTC | Jul 18, 15:10 UTC | 7h 40m |
| 2026-07-17 | UAL115 | SFO → PPT | Jul 17, 20:52 UTC | Jul 18, 04:33 UTC | 7h 41m |
| 2026-07-17 | UAL115 | SFO → PPT | Jul 17, 20:44 UTC | Jul 17, 21:30 UTC | 45m |
| 2026-07-17 | UAL870 | - | Jul 17, 01:05 UTC | Jul 17, 14:10 UTC | 13h 5m |
| 2026-07-16 | UAL839 | - | Jul 16, 07:25 UTC | Jul 16, 21:50 UTC | 14h 25m |
| 2026-07-15 | UAL821 | - | Jul 15, 14:10 UTC | Jul 16, 03:10 UTC | 13h 0m |
| 2026-07-15 | UAL821 | - | Jul 15, 11:20 UTC | Jul 15, 11:30 UTC | 10m |
| 2026-07-15 | UAL821 | - | Jul 15, 09:05 UTC | Jul 15, 09:15 UTC | 10m |
| 2026-07-15 | UAL821 | HKG → LAX | Jul 15, 09:05 UTC | Jul 15, 11:22 UTC | 2h 17m |
| 2026-07-15 | UAL820 | HKG → BKK | Jul 15, 00:01 UTC | Jul 15, 02:10 UTC | 2h 9m |
| 2026-07-15 | UAL820 | - | Jul 15, 00:00 UTC | Jul 15, 00:10 UTC | 10m |
| 2026-07-14 | UAL820 | - | Jul 14, 07:50 UTC | Jul 14, 21:20 UTC | 13h 30m |
| 2026-07-13 | UAL353 | - | Jul 13, 23:15 UTC | Jul 14, 03:45 UTC | 4h 30m |
| 2026-07-13 | UAL2096 | - | Jul 13, 15:40 UTC | Jul 13, 20:25 UTC | 4h 45m |
| 2026-07-13 | UAL2096 | LAX → EWR | Jul 13, 15:41 UTC | Jul 13, 20:26 UTC | 4h 45m |
| 2026-07-12 | UAL199 | - | Jul 12, 16:30 UTC | Jul 12, 18:05 UTC | 1h 35m |
| 2026-07-12 | UAL199 | PVG → LAX | Jul 12, 15:36 UTC | Jul 13, 02:55 UTC | 11h 19m |
| 2026-07-12 | UAL199 | - | Jul 12, 10:30 UTC | Jul 13, 03:01 UTC | 16h 30m |
| 2026-07-12 | UAL198 | - | Jul 12, 01:00 UTC | Jul 12, 12:30 UTC | 11h 30m |
| 2026-07-12 | UAL198 | LAX → PVG | Jul 12, 01:01 UTC | Jul 12, 13:21 UTC | 12h 20m |
| 2026-07-11 | UAL935 | - | Jul 11, 12:30 UTC | Jul 11, 22:55 UTC | 10h 25m |
| 2026-07-10 | UAL923 | - | Jul 10, 23:00 UTC | Jul 11, 08:50 UTC | 9h 50m |
| 2026-07-10 | UAL99 | MEL → LAX | Jul 10, 00:00 UTC | Jul 10, 14:05 UTC | 14h 5m |
| 2026-07-09 | UAL98 | - | Jul 9, 06:45 UTC | Jul 9, 21:30 UTC | 14h 45m |
| 2026-07-09 | UAL98 | LAX → MEL | Jul 9, 06:09 UTC | Jul 9, 21:34 UTC | 15h 25m |
| 2026-07-08 | UAL199 | PVG → LAX | Jul 8, 13:05 UTC | Jul 8, 14:55 UTC | 1h 50m |
| 2026-07-08 | UAL199 | - | Jul 8, 06:45 UTC | Jul 8, 23:50 UTC | 17h 5m |
| 2026-07-07 | UAL198 | - | Jul 7, 20:40 UTC | Jul 8, 07:30 UTC | 10h 50m |
| 2026-07-07 | UAL198 | LAX → PVG | Jul 7, 20:31 UTC | Jul 8, 09:22 UTC | 12h 51m |
| 2026-07-07 | UAL842 | SYD → LAX | Jul 7, 00:01 UTC | Jul 7, 13:06 UTC | 13h 5m |
| 2026-07-07 | UAL842 | - | Jul 7, 00:10 UTC | Jul 7, 01:10 UTC | 1h 0m |
| 2026-07-06 | UAL839 | - | Jul 6, 06:30 UTC | Jul 6, 20:50 UTC | 14h 20m |
| 2026-07-05 | UAL935 | - | Jul 5, 12:25 UTC | Jul 5, 22:45 UTC | 10h 20m |
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 N29984 page for operator, model, and routing details .