sensors Mode-S transponder
A18D29
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N19986 · BOEING 787-9 Dreamliner · operated by UNITED AIRLINES INC
- Hex
- A18D29
- Octal
- 50306451
- Decimal
- 10,587,433
- Country
- US
- Tail
- N19986
- Type
- B789
- Flights observed
- 125
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 10h ago
Last known position
Country allocation
The ICAO 24-bit address A18D29 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 |
|---|---|---|---|
| UAL181 | United Airlines | 11 | 2026-04-15 |
| UAL178 | United Airlines | 6 | 2026-04-27 |
| UAL177 | United Airlines | 6 | 2026-04-26 |
| UAL78 | United Airlines | 5 | 2026-05-17 |
| UAL182 | United Airlines | 5 | 2026-04-15 |
| UAL143 | United Airlines | 5 | 2026-04-30 |
| UAL82 | United Airlines | 4 | 2026-05-23 |
| UAL79 | United Airlines | 4 | 2026-05-16 |
| UAL63 | United Airlines | 4 | 2026-05-13 |
| UAL27 | United Airlines | 4 | 2026-04-16 |
| UAL262 | United Airlines | 4 | 2026-04-28 |
| UAL26 | United Airlines | 4 | 2026-04-16 |
| UAL123 | United Airlines | 4 | 2026-05-26 |
| UAL870 | United Airlines | 3 | 2026-05-28 |
| UAL198 | United Airlines | 3 | 2026-05-06 |
| UAL142 | United Airlines | 3 | 2026-04-13 |
| UAL1122 | United Airlines | 3 | 2026-05-18 |
| UAL892 | United Airlines | 2 | 2026-05-29 |
| UAL83 | United Airlines | 2 | 2026-05-23 |
| UAL772 | United Airlines | 2 | 2026-05-09 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-29 | UAL2480 | BOS → SFO | May 29, 21:15 UTC | May 30, 01:55 UTC | 4h 40m |
| 2026-05-29 | UAL892 | ICN → SFO | May 29, 08:25 UTC | May 29, 10:00 UTC | 1h 35m |
| 2026-05-29 | UAL892 | ICN → SFO | May 29, 08:26 UTC | May 29, 18:25 UTC | 9h 59m |
| 2026-05-28 | UAL893 | SFO → ICN | May 28, 18:10 UTC | May 29, 06:15 UTC | 12h 5m |
| 2026-05-28 | UAL870 | SYD → SFO | May 28, 00:45 UTC | May 28, 13:55 UTC | 13h 10m |
| 2026-05-28 | UAL870 | SYD → SFO | May 28, 00:45 UTC | May 28, 13:58 UTC | 13h 13m |
| 2026-05-28 | UAL870 | SYD → SFO | May 28, 00:50 UTC | May 28, 01:50 UTC | 1h 0m |
| 2026-05-27 | UAL863 | SFO → SYD | May 27, 06:44 UTC | May 27, 20:45 UTC | 14h 1m |
| 2026-05-26 | UAL1227 | PHX → IAD | May 26, 17:39 UTC | May 26, 22:54 UTC | 5h 15m |
| 2026-05-26 | UAL123 | ANC → ORD | May 26, 07:10 UTC | May 26, 08:15 UTC | 1h 5m |
| 2026-05-26 | UAL123 | ANC → ORD | May 26, 07:02 UTC | May 26, 14:06 UTC | 7h 4m |
| 2026-05-25 | UAL122 | IAD → LHR | May 25, 14:20 UTC | May 25, 20:30 UTC | 6h 10m |
| 2026-05-24 | UAL2480 | BOS → SFO | May 24, 21:00 UTC | May 24, 23:46 UTC | 2h 46m |
| 2026-05-24 | UAL1593 | LGA → DEN | May 24, 14:00 UTC | May 24, 19:20 UTC | 5h 20m |
| 2026-05-23 | UAL83 | DEL → EWR | May 23, 18:30 UTC | May 24, 10:10 UTC | 15h 40m |
| 2026-05-23 | UAL82 | EWR → DEL | May 23, 01:44 UTC | May 23, 15:26 UTC | 13h 42m |
| 2026-05-23 | UAL82 | EWR → DEL | May 23, 01:40 UTC | May 23, 11:50 UTC | 10h 9m |
| 2026-05-22 | UAL1173 | SJU → EWR | May 22, 20:25 UTC | May 22, 21:10 UTC | 45m |
| 2026-05-22 | UAL1173 | SJU → EWR | May 22, 17:45 UTC | May 22, 17:55 UTC | 10m |
| 2026-05-22 | UAL2143 | EWR → SJU | May 22, 15:10 UTC | May 22, 15:35 UTC | 25m |
| 2026-05-22 | UAL2143 | EWR → SJU | May 22, 12:20 UTC | May 22, 12:55 UTC | 35m |
| 2026-05-20 | UAL83 | DEL → EWR | May 20, 20:05 UTC | May 21, 11:25 UTC | 15h 20m |
| 2026-05-20 | UAL82 | EWR → DEL | May 20, 02:25 UTC | May 20, 16:55 UTC | 14h 31m |
| 2026-05-20 | UAL82 | EWR → DEL | May 20, 01:26 UTC | May 20, 16:51 UTC | 15h 25m |
| 2026-05-18 | UAL1122 | EWR → CPT | May 18, 01:11 UTC | May 18, 03:01 UTC | 1h 50m |
| 2026-05-18 | UAL1122 | EWR → CPT | May 18, 01:15 UTC | May 18, 03:01 UTC | 1h 45m |
| 2026-05-17 | UAL78 | NRT → EWR | May 17, 08:51 UTC | May 17, 20:27 UTC | 11h 36m |
| 2026-05-17 | UAL78 | NRT → EWR | May 17, 08:35 UTC | May 17, 09:10 UTC | 35m |
| 2026-05-16 | UAL79 | EWR → NRT | May 16, 15:57 UTC | May 17, 05:11 UTC | 13h 14m |
| 2026-05-16 | UAL79 | EWR → NRT | May 16, 15:50 UTC | May 17, 00:10 UTC | 8h 20m |
| 2026-05-15 | UAL187 | JNB → EWR | May 15, 20:05 UTC | May 16, 11:21 UTC | 15h 16m |
| 2026-05-15 | UAL188 | EWR → JNB | May 15, 02:00 UTC | May 15, 16:00 UTC | 13h 59m |
| 2026-05-14 | UAL78 | NRT → EWR | May 14, 08:30 UTC | May 14, 20:40 UTC | 12h 10m |
| 2026-05-13 | UAL7 | IAH → NRT | May 13, 15:35 UTC | May 14, 04:00 UTC | 12h 25m |
| 2026-05-13 | UAL63 | GRU → IAH | May 13, 01:20 UTC | May 13, 10:45 UTC | 9h 25m |
| 2026-05-13 | UAL63 | GRU → IAH | May 13, 01:11 UTC | May 13, 10:43 UTC | 9h 32m |
| 2026-05-12 | UAL62 | IAH → GRU | May 12, 00:03 UTC | May 12, 08:37 UTC | 8h 34m |
| 2026-05-11 | UAL6 | NRT → IAH | May 11, 08:25 UTC | May 11, 20:00 UTC | 11h 36m |
| 2026-05-10 | UAL79 | EWR → NRT | May 10, 15:47 UTC | May 11, 04:34 UTC | 12h 47m |
| 2026-05-10 | UAL79 | EWR → NRT | May 10, 15:39 UTC | May 11, 04:30 UTC | 12h 50m |
| 2026-05-09 | UAL1855 | ORD → BOS | May 9, 20:30 UTC | May 10, 00:15 UTC | 3h 45m |
| 2026-05-09 | UAL1855 | ORD → BOS | May 9, 20:31 UTC | May 10, 01:03 UTC | 4h 32m |
| 2026-05-09 | UAL772 | DEN → DFW | May 9, 05:20 UTC | May 9, 15:35 UTC | 10h 15m |
| 2026-05-09 | UAL772 | DEN → DFW | May 9, 04:29 UTC | May 9, 15:31 UTC | 11h 2m |
| 2026-05-08 | UAL771 | BNA → ORD | May 8, 06:30 UTC | May 8, 19:15 UTC | 12h 45m |
| 2026-05-08 | UAL771 | BNA → ORD | May 8, 06:24 UTC | May 8, 20:31 UTC | 14h 7m |
| 2026-05-07 | UAL199 | PVG → LAX | May 7, 13:10 UTC | May 7, 14:40 UTC | 1h 30m |
| 2026-05-07 | UAL199 | PVG → LAX | May 7, 06:30 UTC | May 7, 23:29 UTC | 17h 0m |
| 2026-05-06 | UAL198 | LAX → PVG | May 6, 20:20 UTC | May 7, 14:40 UTC | 18h 21m |
| 2026-05-06 | UAL198 | LAX → PVG | May 6, 20:10 UTC | May 7, 08:05 UTC | 11h 55m |
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 N19986 page for operator, model, and routing details .