sensors Mode-S transponder
AAA4DC
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N785UA · BOEING 777-200 · operated by UNITED AIRLINES INC
- Hex
- AAA4DC
- Octal
- 52522334
- Decimal
- 11,183,324
- Country
- US
- Tail
- N785UA
- Type
- B772
- Flights observed
- 219
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 1h ago
Last known position
Country allocation
The ICAO 24-bit address AAA4DC 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 |
|---|---|---|---|
| UAL969 | - | 15 | 2026-06-25 |
| UAL968 | - | 11 | 2026-06-24 |
| UAL984 | - | 9 | 2026-07-11 |
| UAL59 | - | 8 | 2026-07-12 |
| UAL932 | United Airlines | 6 | 2026-04-30 |
| UAL672 | - | 6 | 2026-07-05 |
| UAL58 | - | 6 | 2026-07-11 |
| UAL506 | - | 6 | 2026-06-29 |
| UAL930 | United Airlines | 5 | 2026-05-17 |
| UAL925 | United Airlines | 5 | 2026-06-07 |
| UAL888 | United Airlines | 5 | 2026-06-12 |
| UAL23 | - | 5 | 2026-07-01 |
| UAL943 | United Airlines | 4 | 2026-06-08 |
| UAL927 | United Airlines | 4 | 2026-04-18 |
| UAL900 | United Airlines | 4 | 2026-04-13 |
| UAL889 | United Airlines | 4 | 2026-06-13 |
| UAL884 | United Airlines | 4 | 2026-06-05 |
| UAL880 | United Airlines | 4 | 2026-05-13 |
| UAL852 | - | 4 | 2026-06-22 |
| UAL819 | United Airlines | 4 | 2026-05-12 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-14 | UAL2143 | - | Jul 14, 12:20 UTC | Jul 14, 13:00 UTC | 40m |
| 2026-07-13 | UAL366 | SFO → EWR | Jul 13, 21:42 UTC | Jul 14, 02:35 UTC | 4h 53m |
| 2026-07-13 | UAL366 | SFO → EWR | Jul 13, 21:45 UTC | Jul 14, 02:40 UTC | 4h 55m |
| 2026-07-12 | UAL59 | FRA → SFO | Jul 12, 11:24 UTC | Jul 12, 22:11 UTC | 10h 47m |
| 2026-07-12 | UAL59 | - | Jul 12, 11:15 UTC | Jul 12, 12:50 UTC | 1h 35m |
| 2026-07-11 | UAL58 | SFO → FRA | Jul 11, 21:25 UTC | Jul 12, 07:20 UTC | 9h 55m |
| 2026-07-11 | UAL984 | - | Jul 11, 07:30 UTC | Jul 11, 18:35 UTC | 11h 5m |
| 2026-07-11 | UAL984 | CDG → SFO | Jul 11, 07:39 UTC | Jul 11, 18:28 UTC | 10h 49m |
| 2026-07-10 | UAL57 | - | Jul 10, 23:00 UTC | Jul 11, 05:25 UTC | 6h 25m |
| 2026-07-10 | UAL31 | - | Jul 10, 08:00 UTC | Jul 10, 16:25 UTC | 8h 25m |
| 2026-07-09 | UAL30 | - | Jul 9, 22:10 UTC | Jul 10, 05:25 UTC | 7h 15m |
| 2026-07-09 | UAL905 | LHR → EWR | Jul 9, 08:55 UTC | Jul 9, 15:57 UTC | 7h 2m |
| 2026-07-09 | UAL905 | LHR → EWR | Jul 9, 08:55 UTC | Jul 9, 16:00 UTC | 7h 5m |
| 2026-07-08 | UAL918 | IAD → LHR | Jul 8, 22:50 UTC | Jul 9, 05:35 UTC | 6h 45m |
| 2026-07-08 | UAL914 | CDG → IAD | Jul 8, 10:45 UTC | Jul 8, 18:20 UTC | 7h 35m |
| 2026-07-07 | UAL990 | SFO → CDG | Jul 7, 22:00 UTC | Jul 8, 08:05 UTC | 10h 5m |
| 2026-07-07 | UAL34 | - | Jul 7, 08:10 UTC | Jul 7, 17:55 UTC | 9h 45m |
| 2026-07-06 | UAL35 | SFO → KIX | Jul 6, 18:42 UTC | Jul 7, 05:31 UTC | 10h 49m |
| 2026-07-06 | UAL35 | - | Jul 6, 18:40 UTC | Jul 6, 23:55 UTC | 5h 15m |
| 2026-07-05 | UAL673 | - | Jul 5, 14:30 UTC | Jul 6, 02:10 UTC | 11h 40m |
| 2026-07-05 | UAL672 | SFO → BCN | Jul 5, 01:29 UTC | Jul 5, 11:54 UTC | 10h 25m |
| 2026-07-05 | UAL672 | - | Jul 5, 01:15 UTC | Jul 5, 11:00 UTC | 9h 45m |
| 2026-07-04 | UAL59 | FRA → SFO | Jul 4, 11:15 UTC | Jul 4, 22:15 UTC | 11h 0m |
| 2026-07-03 | UAL58 | - | Jul 3, 21:30 UTC | Jul 4, 00:35 UTC | 3h 5m |
| 2026-07-03 | UAL58 | SFO → FRA | Jul 3, 21:22 UTC | Jul 4, 07:33 UTC | 10h 11m |
| 2026-07-02 | UAL2328 | - | Jul 2, 20:25 UTC | Jul 3, 01:45 UTC | 5h 20m |
| 2026-07-02 | UAL18 | - | Jul 2, 08:05 UTC | Jul 2, 16:15 UTC | 8h 10m |
| 2026-07-01 | UAL19 | EWR → MXP | Jul 1, 22:13 UTC | Jul 2, 05:32 UTC | 7h 19m |
| 2026-07-01 | UAL19 | - | Jul 1, 22:10 UTC | Jul 2, 03:00 UTC | 4h 50m |
| 2026-07-01 | UAL22 | DUB → EWR | Jul 1, 09:00 UTC | Jul 1, 15:45 UTC | 6h 45m |
| 2026-07-01 | UAL23 | EWR → DUB | Jul 1, 00:15 UTC | Jul 1, 06:01 UTC | 5h 46m |
| 2026-07-01 | UAL23 | EWR → DUB | Jul 1, 00:10 UTC | Jul 1, 06:20 UTC | 6h 10m |
| 2026-06-30 | UAL1141 | SFO → EWR | Jun 30, 07:45 UTC | Jun 30, 12:25 UTC | 4h 40m |
| 2026-06-29 | UAL506 | - | Jun 29, 14:14 UTC | Jun 29, 22:15 UTC | 8h 0m |
| 2026-06-29 | UAL506 | FCO → SFO | Jun 29, 14:07 UTC | Jun 30, 01:58 UTC | 11h 51m |
| 2026-06-29 | UAL507 | SFO → FCO | Jun 29, 00:24 UTC | Jun 29, 11:20 UTC | 10h 55m |
| 2026-06-27 | UAL59 | - | Jun 27, 11:25 UTC | Jun 27, 22:04 UTC | 10h 40m |
| 2026-06-27 | UAL59 | FRA → SFO | Jun 27, 11:29 UTC | Jun 27, 22:06 UTC | 10h 37m |
| 2026-06-26 | UAL58 | - | Jun 26, 21:15 UTC | Jun 27, 07:30 UTC | 10h 15m |
| 2026-06-26 | UAL1593 | EWR → SFO | Jun 26, 13:49 UTC | Jun 26, 19:09 UTC | 5h 20m |
| 2026-06-26 | UAL1593 | - | Jun 26, 13:45 UTC | Jun 26, 19:00 UTC | 5h 15m |
| 2026-06-26 | UAL1141 | - | Jun 26, 06:00 UTC | Jun 26, 10:25 UTC | 4h 25m |
| 2026-06-25 | UAL969 | AMS → SFO | Jun 25, 14:26 UTC | Jun 26, 00:57 UTC | 10h 31m |
| 2026-06-25 | UAL969 | AMS → SFO | Jun 25, 14:26 UTC | Jun 26, 01:06 UTC | 10h 40m |
| 2026-06-25 | UAL969 | - | Jun 25, 14:44 UTC | Jun 25, 16:05 UTC | 1h 20m |
| 2026-06-24 | UAL968 | SFO → AMS | Jun 24, 22:35 UTC | Jun 25, 08:14 UTC | 9h 40m |
| 2026-06-23 | UAL969 | AMS → SFO | Jun 23, 13:21 UTC | Jun 23, 23:50 UTC | 10h 29m |
| 2026-06-23 | UAL969 | - | Jun 23, 13:19 UTC | Jun 23, 18:20 UTC | 5h 0m |
| 2026-06-23 | UAL968 | SFO → AMS | Jun 23, 00:28 UTC | Jun 23, 10:15 UTC | 9h 47m |
| 2026-06-23 | UAL968 | - | Jun 23, 00:30 UTC | Jun 23, 03:00 UTC | 2h 30m |
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 N785UA page for operator, model, and routing details .