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
- 111
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 5d 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 | United Airlines | 8 | 2026-05-25 |
| UAL932 | United Airlines | 6 | 2026-04-30 |
| UAL968 | United Airlines | 5 | 2026-05-23 |
| UAL930 | United Airlines | 5 | 2026-05-17 |
| UAL984 | United Airlines | 4 | 2026-05-07 |
| UAL927 | United Airlines | 4 | 2026-04-18 |
| UAL925 | United Airlines | 4 | 2026-04-16 |
| UAL900 | United Airlines | 4 | 2026-04-13 |
| UAL880 | United Airlines | 4 | 2026-05-13 |
| UAL819 | United Airlines | 4 | 2026-05-12 |
| UAL47 | United Airlines | 3 | 2026-05-10 |
| UAL46 | United Airlines | 3 | 2026-05-09 |
| UAL23 | United Airlines | 3 | 2026-05-19 |
| UAL22 | United Airlines | 3 | 2026-05-19 |
| UAL18 | United Airlines | 3 | 2026-05-20 |
| UAL949 | United Airlines | 2 | 2026-05-16 |
| UAL948 | United Airlines | 2 | 2026-05-16 |
| UAL943 | United Airlines | 2 | 2026-04-21 |
| UAL942 | United Airlines | 2 | 2026-04-21 |
| UAL919 | United Airlines | 2 | 2026-04-29 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-25 | UAL969 | AMS → SFO | May 25, 03:30 UTC | May 25, 08:35 UTC | 5h 5m |
| 2026-05-24 | UAL969 | AMS → SFO | May 24, 16:50 UTC | May 24, 23:46 UTC | 6h 56m |
| 2026-05-24 | UAL969 | AMS → SFO | May 24, 13:00 UTC | May 24, 14:40 UTC | 1h 40m |
| 2026-05-23 | UAL968 | SFO → AMS | May 23, 22:10 UTC | May 24, 07:50 UTC | 9h 40m |
| 2026-05-22 | UAL506 | MSN → DEN | May 22, 15:00 UTC | May 22, 22:30 UTC | 7h 30m |
| 2026-05-22 | UAL506 | MSN → DEN | May 22, 14:57 UTC | May 23, 02:33 UTC | 11h 36m |
| 2026-05-22 | UAL507 | DEN → LGA | May 22, 01:10 UTC | May 22, 13:00 UTC | 11h 50m |
| 2026-05-21 | UAL1777 | EWR → IAH | May 21, 14:40 UTC | May 21, 19:55 UTC | 5h 15m |
| 2026-05-20 | UAL18 | MXP → EWR | May 20, 10:05 UTC | May 20, 12:35 UTC | 2h 30m |
| 2026-05-20 | UAL18 | MXP → EWR | May 20, 10:01 UTC | May 20, 18:11 UTC | 8h 10m |
| 2026-05-20 | UAL19 | EWR → MXP | May 20, 00:20 UTC | May 20, 07:20 UTC | 7h 1m |
| 2026-05-19 | UAL22 | DUB → EWR | May 19, 08:45 UTC | May 19, 15:15 UTC | 6h 30m |
| 2026-05-19 | UAL23 | EWR → DUB | May 19, 00:35 UTC | May 19, 02:15 UTC | 1h 40m |
| 2026-05-19 | UAL23 | EWR → DUB | May 19, 00:20 UTC | May 19, 06:33 UTC | 6h 13m |
| 2026-05-18 | UAL435 | KOA → SFO | May 18, 16:15 UTC | May 18, 21:10 UTC | 4h 54m |
| 2026-05-17 | UAL939 | LHR → SFO | May 17, 15:45 UTC | May 18, 01:50 UTC | 10h 5m |
| 2026-05-17 | UAL930 | SFO → LHR | May 17, 02:50 UTC | May 17, 12:30 UTC | 9h 40m |
| 2026-05-16 | UAL949 | LHR → SFO | May 16, 12:16 UTC | May 16, 14:35 UTC | 2h 20m |
| 2026-05-16 | UAL949 | LHR → SFO | May 16, 12:25 UTC | May 16, 22:12 UTC | 9h 47m |
| 2026-05-16 | UAL948 | SFO → LHR | May 16, 00:30 UTC | May 16, 10:11 UTC | 9h 41m |
| 2026-05-15 | UAL948 | SFO → LHR | May 15, 23:59 UTC | May 16, 10:07 UTC | 10h 8m |
| 2026-05-15 | UAL195 | MUC → SFO | May 15, 09:55 UTC | May 15, 21:05 UTC | 11h 9m |
| 2026-05-14 | UAL102 | IAH → MUC | May 14, 21:55 UTC | May 15, 07:00 UTC | 9h 5m |
| 2026-05-14 | UAL102 | IAH → MUC | May 14, 21:57 UTC | May 15, 07:43 UTC | 9h 46m |
| 2026-05-14 | UAL879 | LHR → IAH | May 14, 09:15 UTC | May 14, 18:40 UTC | 9h 25m |
| 2026-05-14 | UAL879 | LHR → IAH | May 14, 09:25 UTC | May 14, 18:43 UTC | 9h 18m |
| 2026-05-13 | UAL880 | IAH → LHR | May 13, 22:00 UTC | May 14, 06:45 UTC | 8h 45m |
| 2026-05-13 | UAL818 | EZE → IAH | May 13, 00:10 UTC | May 13, 09:45 UTC | 9h 35m |
| 2026-05-12 | UAL819 | IAH → EZE | May 12, 03:50 UTC | May 12, 11:20 UTC | 7h 30m |
| 2026-05-12 | UAL819 | IAH → EZE | May 12, 01:52 UTC | May 12, 11:14 UTC | 9h 22m |
| 2026-05-11 | UAL4 | LHR → IAH | May 11, 13:10 UTC | May 11, 22:35 UTC | 9h 25m |
| 2026-05-11 | UAL5 | IAH → LHR | May 11, 02:30 UTC | May 11, 11:00 UTC | 8h 30m |
| 2026-05-10 | UAL47 | FRA → IAH | May 10, 12:16 UTC | May 10, 23:25 UTC | 11h 9m |
| 2026-05-10 | UAL47 | FRA → IAH | May 10, 12:54 UTC | May 10, 14:49 UTC | 1h 55m |
| 2026-05-09 | UAL46 | IAH → FRA | May 9, 23:35 UTC | May 10, 08:50 UTC | 9h 15m |
| 2026-05-09 | UAL46 | IAH → FRA | May 9, 23:28 UTC | May 10, 08:40 UTC | 9h 12m |
| 2026-05-08 | UAL160 | MUC → IAH | May 8, 10:29 UTC | May 8, 21:25 UTC | 10h 55m |
| 2026-05-07 | UAL194 | SFO → MUC | May 7, 21:12 UTC | May 8, 08:29 UTC | 11h 17m |
| 2026-05-07 | UAL194 | SFO → MUC | May 7, 21:40 UTC | May 8, 08:19 UTC | 10h 39m |
| 2026-05-07 | UAL984 | CDG → SFO | May 7, 18:25 UTC | May 7, 18:45 UTC | 20m |
| 2026-05-07 | UAL984 | CDG → SFO | May 7, 08:00 UTC | May 7, 10:50 UTC | 2h 50m |
| 2026-05-07 | UAL984 | CDG → SFO | May 7, 08:09 UTC | May 7, 18:08 UTC | 9h 59m |
| 2026-05-07 | UAL984 | CDG → SFO | May 7, 08:09 UTC | May 7, 18:38 UTC | 10h 29m |
| 2026-05-06 | UAL915 | IAD → CDG | May 6, 23:00 UTC | May 7, 06:05 UTC | 7h 5m |
| 2026-05-06 | UAL914 | CDG → IAD | May 6, 10:45 UTC | May 6, 18:45 UTC | 7h 59m |
| 2026-05-05 | UAL990 | SFO → CDG | May 5, 21:55 UTC | May 6, 08:20 UTC | 10h 25m |
| 2026-05-04 | UAL673 | SFO → BOS | May 4, 14:35 UTC | May 5, 02:30 UTC | 11h 56m |
| 2026-05-04 | UAL673 | SFO → BOS | May 4, 14:31 UTC | May 5, 02:24 UTC | 11h 53m |
| 2026-05-04 | UAL672 | EWR → ATL | May 4, 01:09 UTC | May 4, 12:04 UTC | 10h 55m |
| 2026-05-04 | UAL672 | EWR → ATL | May 4, 01:00 UTC | May 4, 12:05 UTC | 11h 5m |
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 .